Prescribed Fire: Controlled Burns for Forest and Non-forest Habitats

Homo sapiens owes much of its success as a species to an acquired knowledge of how to make, control, and utilize fire. Using fire to convert the energy stored in combustible materials into light and heat has enabled humankind to expand its range throughout the globe. Indeed, humans in their furless incomplete mammalian state may have never been able to expand their populations outside of tropical latitudes without mastery of fire. It is fire that has enabled man to exploit more of the earth’s resources than any other species. From cooking otherwise unpalatable foods to powering the modern industrial society, fire has set man apart from the rest of the natural world.

In our modern civilizations, we generally look at the unplanned outbreak of fire as a catastrophe requiring our immediate intercession. A building fire, for example, is extinguished as quickly as possible to save lives and property. And fires detected in fields, brush, and woodlands are promptly controlled to prevent their exponential growth. But has fire gone to our heads? Do we have an anthropocentric view of fire? Aren’t there naturally occurring fires that are essential to the health of some of the world’s ecosystems? And to our own safety? Indeed there are. And many species and the ecosystems they inhabit rely on the periodic occurrence of fire to maintain their health and vigor.

**For the war effort-** The campaign to reduce the frequency of forest fires got its start during World War II with distribution of this poster in 1942. The goal was to protect the nation’s timber resources from accidental or malicious loss due to fire caused by man-made ignition sources. The release of the Walt Disney film “Bambi” during the same year and the adoption of the Smokey the Bear mascot in 1944 softened the message’s delivery, but the public relations outreach continued to be a key element of a no-fire policy to save trees for lumber. Protection and management of healthy forest ecosystems in their entirety has only recently become a priority. (National Archives image)

Man has been availed of the direct benefits of fire for possibly 40,000 years or more. Here in the Lower Susquehanna River Watershed, the earliest humans arrived as early as 12,000 years ago—already possessing skills for using fire. Native plants and animals on the other hand, have been part of the ever-changing mix of ecosystems found here for a much longer period of time—millions to tens of millions of years. Many terrestrial native species are adapted to the periodic occurrence of fire. Some, in fact, require it. Most upland ecosystems need an occasional dose of fire, usually ignited by lightning (though volcanism and incoming cosmic projectiles are rare possibilities), to regenerate vegetation, release nutrients, and maintain certain non-climax habitat types.

But much of our region has been deprived of natural-type fires since the time of the clearcutting of the virgin forests during the eighteenth and nineteenth centuries. This absence of a natural fire cycle has contributed to degradation and/or elimination of many forest and non-forest habitats. Without fire, a dangerous stockpile of combustible debris has been collecting, season after season, in some areas for a hundred years or more. Lacking periodic fires or sufficient moisture to sustain prompt decomposition of dead material, wildlands can accumulate enough leaf litter, thatch, dry brush, tinder, and fallen wood to fuel monumentally large forest fires—fires similar to those recently engulfing some areas of the American west. So elimination of natural fire isn’t just a problem for native plants and animals, its a potential problem for humans as well.

Indiangrass on Fire — Indiangrass (seen here), Switchgrass, Big Bluestem, and Little Bluestem are native species requiring periodic forms of disturbance to eliminate competition by woody plants. These warm-season grasses develop roots that penetrate deep into the soil, sometimes to depths of six feet or more, allowing them to survive severe drought and flash fire events. In the tall grass prairies, these extensive root systems allow these grasses to return following heavy grazing by roaming herds of American Bison (Bison bison). Without these habitat disturbances, warm season grasslands succumb to succession in about seven years. With their periodic occurrence, the plants thrive and provide excellent wildlife habitat, erosion control, and grazing forage.

To address the habitat ailments caused by a lack of natural fires, federal, state, and local conservation agencies are adopting the practice of “prescribed fire” as a treatment to restore ecosystem health. A prescribed fire is a controlled burn specifically planned to correct one or more vegetative management problems on a given parcel of land. In the Lower Susquehanna River Watershed, prescribed fire is used to…

- - Eliminate dangerous accumulations of combustible fuels in woodlands.
  - Reduce accumulations of dead plant material that may harbor disease.
  - Provide top kill to promote oak regeneration.
  - Regenerate other targeted species of trees, wildflowers, grasses, and vegetation.
  - Kill non-native plants and promote growth of native plants.
  - Prevent succession.
  - Remove woody growth and thatch from grasslands.
  - Promote fire tolerant species of plants and animals.
  - Create, enhance, and/or manage specialized habitats.
  - Improve habitat for rare species (Regal Fritillary, etc.)
  - Recycle nutrients and minerals contained in dead plant material.

Let’s look at some examples of prescribed fire being implemented right here in our own neighborhood…

Prescribed Fire at Fort Indiantown Gap — Prescribed fire is used regularly at Fort Indiantown Gap Military Reservation in Lebanon County, Pennsylvania, to keep accumulations of woody and herbaceous fuels from accumulating on and around the training range areas where live ordinance and other sources of ignition could otherwise spark large, hard-to-control wildfires.

Prescribed fire in grassland. — A prescribed fire in late winter prevents this grassland consisting of Big Bluestem and native wildflowers from being overtaken by woody growth and invasive species. Fires such as this that are intended to interrupt the process of succession are repeated at least every three to five years.

Prescribed Fire to Control Invasive Species — In its wildlife food plots, prescribed fire is used by the Pennsylvania Game Commission to prevent succession and control invasive species such as Multiflora Rose, instead promoting the growth of native plants.

A woodlot understory choked with combustible fuels and tangles of invasive Multiflora Rose. — An example of a woodlot understory choked with combustible fuels and dense tangles of invasive Multiflora Rose. A forester has the option of prescribing a dose of dormant-season fire for a site like this to reduce the fuel load, top kill non-native vegetation, and regenerate native plants.

Precribed Fire to Eliminate Woody Growth — A dose of prescribed fire was administered on this grassland to kill the woody growth of small trees beginning to overtake the habitat by succession.

Precribed Fire Education Sign at middle creek Wildlife Management Area — The Pennsylvania Game Commission employs prescribed fire at Middle Creek Wildlife Management Area and on many of their other holdings to maintain grasslands.

Prescribed fire is used to eliminate invasive species including Multiflora Rose from grasslands at Middle Creek W.M.A. Annual burns on the property are conducted in a mosaic pattern so that each individual area of the grassland is exposed to the effects of fire only once every two to five years. Without fire or some type of mechanical or chemical intervention, succession by woody trees and shrubs would take hold after about seven years.

Prescribed fire is planned for a fraction of total grassland acreage at Middle Creek W.M.A. each year. Another section of the mosaic is targeted in the following year and yet another in the year that follows that. Because burns are conducted in the spring, grassland cover is available for wildlife throughout the winter. And because each year’s fire burns only a portion of the total grassland acreage, wildlife still has plenty of standing grass in which to take shelter during and after the prescribed fire.

Prescribed fire at Middle Creek W.M.A. provides grassland habitat for dozens of species of birds and mammals including the not-so-common Grasshopper Sparrow…

…and stocked Ring-necked Pheasants that do nest and raise young there.

Prescribed Burn Maintains Savanna-like Habitat — On a few sites in the Lower Susquehanna River Watershed , prescribed fire is being used to establish and maintain savanna-like grasslands. This one, located on a dry, south-facing slope near numerous man-made sources of ignition, can easily be dosed with periodic prescribed burns to both prevent succession and reduce fuel accumulations that may lead to a devastating extreme fire.

Pitch Pines in Savanna-like Habitat — One year following a prescribed burn, this is the autumn appearance of a savanna-like habitat with fire-tolerant Pitch Pine (Pinus rigida), Bear Oak, warm-season grasses, and a variety of nectar-producing wildflowers for pollinators. These ecosystems are magnets for wildlife and may prove to be a manageable fit on sun-drenched sites adjacent to man-made land disturbances and their sources of ignition.

Red-headed Woodpecker Adult and Juvenile — Savanna-like grasslands with oaks and other scattered large trees, some of them dead, make attractive nesting habitat for the uncommon Red-headed Woodpecker.

Wild Turkey in Savanna-like Habitat — Prescribed fire can benefit hungry Wild Turkeys by maintaining savanna-like grasslands for an abundance of grasshoppers and other insects in summer and improving the success of mast-producing oaks for winter.

In the Lower Susquehanna River Watershed, the caterpillar of the rare Eastern Buck Moth feeds on the foliage of the Bear Oak, also known as the Scrub Oak, a shrubby species that relies upon periodic fire to eliminate competition from larger trees in its early successional habitat.

Leaves of the Bear Oak in fall. The Bear Oak regenerates readily from top kill caused by fire.

Reed Canary Grass (Phalaris arundinacea) is a native cool-season grass with a colorful inflorescence in spring. But given the right situation, it can aggressively overtake other species to create a pure stand lacking biodiversity. It is one of the few native species which is sometimes labelled “invasive”.

Prescribed Burn to Reduce Prevalence of Reed Canary Grass — Prescribed fire can be used to reduce an overabundance of Reed Canary Grass and its thatch in wetlands. Periodic burning can help restore species diversity in these habitats for plants and animals including rare species such as the endangered Bog Turtle (Glyptemys muhlenbergii).

On the range areas at Fort Indiantown Gap in Lebanon County, Pennsylvania, disturbances by armored vehicles mimic the effects of large mammals such as the American Bison which periodically trampled grasses to prevent succession and the establishment of woody plants on its prairie habitat. To supplement the activity of the heavy vehicles and to provide suitable habitat for the very rare Regal Fritillary (Speyeria idalia) butterflies found there, prescribed fire is periodically employed to maintain the grasslands on the range. These burns are planned to encourage the growth of “Fort Indiantown Gap Little Bluestem” grass as well as the violets used as host plants by the Regal Fritillary caterpillars. These fires also promote growth of a variety of native summer-blooming wildflowers to provide nectar for the adults butterflies.

Depiction of Pennsylvania's Last American Bison, Killed in Union County in 1801. (Exhibit: State Museum of Pennsylvania, Harrisburg) — A last record of a wild American Bison killed in Pennsylvania was an animal taken in the Susquehanna watershed in Union County in 1801. The species is thereafter considered extirpated from the state. Since that time, natural disturbances needed to regenerate warm-season grasses have been limited primarily to fires and riverine ice scour. The waning occurrence of both has reduced the range of these grasses and their prairie-like ecosystems in the commonwealth. (Exhibit: State Museum of Pennsylvania, Harrisburg)

A male Regal Fritillary on the range at Fort Indiantown Gap, where armored vehicles and prescribed fire provide suitable prairie-like habitat for this vulnerable species.

Honey Bee Collecting Minerals After Prescribed Burn — Prescribed fires return the nutrients and minerals contained in dead plant material to the soil. Following these controlled burns, insects like this Honey Bee can often be seen collecting minerals from the ashes.

Fly Collecting Minerals from Burned Grasses — A Greenbottle Fly gathering minerals from the ash following a prescribed burn.

In Pennsylvania, state law provides landowners and crews conducting prescribed fire burns with reduced legal liability when the latter meet certain educational, planning, and operational requirements. This law may help encourage more widespread application of prescribed fire in the state’s forests and other ecosystems where essential periodic fire has been absent for so very long. Currently in the Lower Susquehanna River Watershed, prescribed fire is most frequently being employed by state agencies on state lands—in particular, the Department of Conservation and Natural Resources on State Forests and the Pennsylvania Game Commission on State Game Lands. Prescribed fire is also part of the vegetation management plan at Fort Indiantown Gap Military Reservation and on the land holdings of the Hershey Trust. Visitors to the nearby Gettysburg National Military Park will also notice prescribed fire being used to maintain the grassland restorations there.

For crews administering prescribed fire burns, late March and early April are a busy time. The relative humidity is often at its lowest level of the year, so the probability of ignition of previous years’ growth is generally at its best. We visited with a crew administering a prescribed fire at Middle Creek Wildlife Management Area last week. Have a look…

Members of a Pennsylvania Game Commission burn crew provide visitors to Middle Creek Wildlife Management Area with an overview of prescribed fire. — Members of a Pennsylvania Game Commission burn crew provide visitors to Middle Creek Wildlife Management Area with an overview of prescribed fire and the equipment and techniques they use to conduct a burn.

Burn Boss Checking Weather — Pennsylvania Game Commission Southeast Region Forester Andy Weaver will fulfill the role of Burn Boss for administering this day’s dose of fire. His responsibilities include assessing the weather before the burn and calculating a probability of ignition.

Burn Boss Briefing Crew — The Burn Boss briefs personnel with information on site layout, water supply location(s), places of refuge, emergency procedures, the event’s goals and plan of action, crew assignments, and the results of the weather check: wind from the northwest at 5 miles per hour, temperature 48 degrees, and the relative humidity 63%. Today’s patient is a parcel of warm-season grasses receiving a dose of fire to eliminate invasive non-native plants, woody growth, and thatch. The probability of ignition is 20%, but improving by the minute.

Prescribed Fire Test Burn — To begin the burn, a test fire is started in the downwind corner of the parcel, which also happens to be the bottom of the slope. Fuel ignition is good. The burn can proceed.

Igniting the Fire — Crews proceed uphill from the location of the test fire while igniting combustibles along both flanks of the area being treated.

Prescribed Fire Crew Member with Equipment — A drip torch is used to ignite the dried stems and leaves of warm-season grasses and wildflowers. Each member of the burn crew wears Nomex fire-resistant clothing and carries safety equipment including a two-way radio, a hydration pack, and a cocoon-like emergency fire shelter.

Wildfire ATV — An all-terrain vehicle equipped with various tools, a fire pump, hose, and a small water tank accompanies the crew on each flank of the fire.

Effective Fire Break — With green cool-season grasses already growing on the trails surrounding the burn zone, very little water was used to contain this prescribed fire. Where such convenient fire breaks don’t already exist, crews carry tools including chain saws, shovels, and leaf blowers to create their own. They also carry flame swatters, backpack water pumps, shovels, and other tools to extinguish fires if necessary. None of these items were needed to control this particular fire.

Halting the Process of Succession in a Grassland with Prescribed Fire — This fast-burning fire provides enough heat to damage the cambium layer of the woody tree and shrub saplings in this parcel being maintained as a grassland/wildflower plot, thus the process of succession is forestalled. Burns conducted during previous years on this and adjacent fields have also controlled aggressive growth of invasive Multiflora Rose and Olives (Elaeagnus species).

Containing the Fire on the Flanks — Crews proceed up the slope while maintaining the perimeter by igniting dry plant material along the flanks of the burn zone.

The Crew Monitors the Burn — Ignition complete, the crews monitor the fire.

Prescribed Fire: Natural Mosaic-style Burn Pattern — The Burn Boss surveys the final stages of a safe and successful prescribed fire. The fire has left behind a mosaic of burned and unburned areas, just as a naturally occurring event may have done. Wildlife dodging the flames may be taking refuge in the standing grasses, so there is no remedial attempt to go back and ignite these areas. They’ll be burned during prescribed fires in coming years.

By June, this grassland will again be lush and green with warm-season grasses and blooming wildflowers like this Common Milkweed being visited by a Great Spangled Fritillary.

And later in the summer, Eastern Tiger Swallowtails on Joe-pye Weed.

Bobolinks in Indiangrass — Bobolinks glow in the late August sun while taking flight from a stand of warm-season grasses maintained using springtime prescribed fire. The small dots on the dark background at the top of the image are multitudes of flying insects, many of them pollinators. The vegetation is predominately Indiangrass, excellent winter cover for birds, mammals, and other wildlife.

Prescribed burns aren’t a cure-all for what ails a troubled forest or other ecosystem, but they can be an effective remedy for deficiencies caused by a lack of periodic episodes of naturally occurring fire. They are an important option for modern foresters, wildlife managers, and other conservationists.

February 22, 2024February 24, 2024

Time to Order Trees and Shrubs for Spring

It’s that time of year. Your local county conservation district is taking orders for their annual tree sale and it’s a deal that can’t be beat. Order now for pickup in April.

The prices are a bargain and the selection includes the varieties you need to improve wildlife habitat and water quality on your property. For species descriptions and more details, visit each tree sale web page (click the sale name highlighted in blue). And don’t forget to order packs of evergreens for planting in mixed clumps and groves to provide winter shelter and summertime nesting sites for our local native birds. They’re only $12.00 for a bundle of 10.

Mature Trees in a Suburban Neighborhood — It’s the most desirable block in town, not because the houses are any different from others built during the post-war years of the mid-twentieth century, but because the first owners of these domiciles had the good taste and foresight to plant long-lived trees on their lots, the majority of them native species. Pin Oak, Northern Red Oak, Yellow Poplar, Flowering Dogwood (Cornus florida), Eastern Red Cedar, Eastern White Pine, Eastern Hemlock, Norway Spruce, and American Holly dominate the landscape and create excellent habitat for birds and other wildlife. These 75-year-old plantings provide an abundance of shade in summer and thermal stability in winter, making it a “cool” place to live or take a stroll at any time of the year.

Cumberland County Conservation District Annual Tree Seedling Sale—

Orders due by: Friday, March 22, 2024

Pickup on: Thursday, April 18, 2024 or Friday, April 19, 2024

Cumberland County Conservation District is taking orders for Common Winterberry, the ideal small shrub for wet soil anywhere on your property. To get berries, you’ll need both males and females, so buy a bunch and plant them in a clump or scattered group.

To live for a century or more like this towering giant, a Pin Oak needs to grow in well-drained soils with adequate moisture. These sturdy shade providers do well along streams and on low ground receiving clean runoff from hillsides, roofs, streets, and parking areas. As they age, Pin Oaks can fail to thrive and may become vulnerable to disease in locations where rainfall is not adequately infiltrated into the soil. Therefore, in drier areas such as raised ground or slopes, avoid the Pin Oak and select the more durable Northern Red Oak for planting. This year, Pin Oaks are available from the Cumberland and Lancaster County Conservation Districts, while Dauphin, Lancaster, Lebanon, and York Counties are taking orders for Northern Red Oaks.

The Cumberland County Conservation District is again offering a “Showy Northeast Native Wildflower and Grass Mix” for seeding your own pollinator meadow or garden. It consists of more than twenty species including this perennial favorite, Purple Coneflower.

Dauphin County Conservation District Seedling Sale—

Orders due by: Monday, March 18, 2024

Pickup on: Thursday, April 18, 2024 or Friday, April 19, 2024

The Eastern Redbud is small tree native to our forest edges, particularly in areas of the Piedmont Province with Triassic geology (Furnace Hills, Conewago Hills, Gettysburg/Hammer Creek Formations, etc.) Also known as the Judas Tree, the redbud’s brilliant flowers are followed by heart-shaped leaves. As seen here, it is suitable for planting near houses and other buildings. Eastern Redbud seedlings are being offered through tree sales in Dauphin, Cumberland, and Lancaster Counties.

Lancaster County Annual Tree Seedling Sale—

Orders due by: Friday, March 8, 2024

Pickup on: Friday, April 12, 2024

The Yellow Poplar, often called Tuliptree or Tulip Poplar for its showy flowers, is a sturdy, fast-growing deciduous tree native to forests throughout the Lower Susquehanna River Watershed. Its pole-straight growth habit in shady woodlands becomes more spreading and picturesque when the plant is grown as a specimen or shade tree in an urban or suburban setting. The Yellow Poplar can live for hundreds of years and is a host plant for the Eastern Tiger Swallowtail butterfly. It is available this year from the Lancaster County Conservation District.

The American Sweetgum, also known as Sweet Gum, is a large, long-lived tree adorned with a mix of vibrant colors in autumn.

American Goldfinches and Pine Siskin on Sweet Gum — Ever wonder where all the American Goldfinches and particularly the Pine Siskins go after passing through our region in fall? Well, many are headed to the lowland forests of the Atlantic Coastal Plain where they feed on an abundance of seeds contained in spiky American Sweetgum fruits. In the Piedmont and Ridge and Valley Provinces of the Lower Susquehanna River Watershed, American Sweetgum transplants can provide enough sustenance to sometimes lure our friendly finches into lingering through the winter.

Sweet Gum in a Beaver Pond — The American Sweetgum is a versatile tree. It can be planted on upland sites as well as in wet ground along streams, lakes, and rivers. In the beaver pond seen here it is the dominate tree species. This year, you can buy the American Sweetgum from the Lancaster County Conservation District.

"Red-twig Dogwood" — “Red-twig Dogwood” is a group of similar native shrubs that, in our region, includes Silky Dogwood and the more northerly Red-Osier Dogwood (Cornus sericea). Both have clusters of white flowers in spring and showy red twigs in winter. They are an excellent choice for wet soils. Landscapers often ruin these plants by shearing them off horizontally a foot or two from the ground each year. To produce flowers and fruit, and to preserve winter attractiveness, trim them during dormancy by removing three-year-old and older canes at ground level, letting younger growth untouched.

Silky Dogwood Stream Buffer — “Red-twig Dogwoods” make ideal mass plantings for streamside buffers and remain showy through winter, even on a gloomy day. They not only mitigate nutrient and sediment pollution, they provide excellent food and cover for birds and other wildlife. Both Silky and Red-osier Dogwoods are available for sale through the Lancaster County Conservation District as part of their special multi-species offers, the former is included in its “Beauty Pack” and the latter in its “Wildlife Pack”. The similar Gray Dogwood (Cornus racemosa) is being offered for sale by the York County Conservation District.

Lebanon County Conservation District Tree and Plant Sale—

Orders due by: Friday, March 8, 2024

Pickup on: Friday, April 19, 2024

Common Pawpaw flower — The unique maroon flowers of the Common Pawpaw produce banana-like fruits in summer. These small native trees grow best in damp, well-drained soils on slopes along waterways, where they often form clonal understory patches. To get fruit, plant a small grove to increase the probability of pollination. The Common Pawpaw is a host plant for the Zebra Swallowtail butterfly. It is available through both the Lebanon and Lancaster County sales.

The Eastern Red Cedar provides excellent food, cover, and nesting sites for numerous songbirds. Planted in clumps of dozens or groves of hundreds of trees, they can provide winter shelter for larger animals including deer and owls. The Eastern Red Cedar is being offered for purchase through both the Lebanon and Lancaster County Conservation Districts.

Hybrid American Chestnut — Care to try your hand at raising some chestnuts? Lebanon County Conservation District has hybrid American Chestnut seedlings for sale.

Perry County Conservation District Tree Sale—

Orders due by: Sunday, March 24, 2024

Pickup on: Thursday, April 11, 2024

Pollinator Garden — In addition to a selection of trees and shrubs, the Perry County Conservation District is again selling wildflower seed mixes for starting your own pollinator meadow or garden. For 2024, they have both a “Northeast Perennials and Annuals Mix” and a “Butterfly and Hummingbird Seed Mix” available. Give them a try so you can give up the mower!

Again this year, Perry County is offering bluebird nest boxes for sale. The price?—just $12.00.

Eastern Bluebird — Wait, what?,…twelve bucks,…that’s cheaper than renting!

York County Conservation District Seedling Sale—

Orders due by: Friday, March 15, 2024

Pickup on: Thursday, April 11, 2024

Buttonbush flower — The Buttonbush, a shrub of wet soils, produces a cosmic-looking flower. It grows well in wetlands, along streams, and in rain gardens. Buttonbush seedlings are for sale from both the York and Lancaster County Conservation Districts.

To get your deciduous trees like gums, maples, oaks, birches, and poplars off to a safe start, conservation district tree sales in Cumberland, Dauphin, Lancaster, and Perry Counties are offering protective tree shelters. Consider purchasing these plastic tubes and supporting stakes for each of your hardwoods, especially if you have hungry deer in your neighborhood.

Deciduous Tree Planting Protected by Shelters — Tree shelters protect newly transplanted seedlings from browsing deer, klutzy hikers, visually impaired mower operators, and other hazards.

There you have it. Be sure to check out each tree sale’s web page to find the selections you like, then get your order placed. The deadlines will be here before you know it and you wouldn’t want to miss values like these!

January 26, 2024January 26, 2024

The Fog of a January Thaw

As week-old snow and ice slowly disappears from the Lower Susquehanna River Watershed landscape, we ventured out to see what might be lurking in the dense clouds of fog that for more than two days now have accompanied a mid-winter warm spell.

York Haven Dam Powerhouse — After freezing to a slushy consistency earlier this week, the Susquehanna is already beginning to thaw. Below the York Haven Dam at Conewago Falls, the water is open and ice-free.

Mallards and a pair of American Wigeon on a frozen lake. — On frozen man-made lakes and ponds, geese and ducks like these Mallards and American Wigeon are presently concentrated around small pockets of open water.

American Robin in a Callery pear — During the past ten days, American Robin numbers have exploded throughout the lower Susquehanna valley. The majority of these birds may be a mix of both those coming south to escape the late onset of wintry conditions to our north and those inching north into our region as early spring migrants.

American Robin — The January thaw has melted the snow from lawns and fields to provide thousands of visiting robins with a chance to forage for earthworms.

Cooper's Hawk — A visit by this young Cooper’s Hawk to the susquehannnawildlife.net headquarters garden sent songbirds scrambling…

…but did nothing to unnerve our resident Eastern Gray Squirrels,…

But earlier in the week, when heavy snow cover in the rural areas surrounding our urbanized neighborhood made it difficult for rodent-eating raptors to find food, we received brief visits from both a Red-tailed Hawk…

…and this young Red-shouldered Hawk, an uncommon bird of prey most often found in wet woods and other lowlands.

Red-shouldered Hawk in flight. — Unimpressed, each of our visiting buteos remained for just a few minutes before moving on in search of more favorable hunting grounds and prey.

Early Successional Growth — As snow melted and exposed bare ground in fields of early successional growth, we encountered…

…a flock of White-crowned Sparrows, most in first-winter plumage…

…and at least a dozen American Tree Sparrows. During the twentieth century, these handsome songbirds were regular winter visitors to the lower Susquehanna region. During recent decades, they’ve become increasingly more difficult to find. Currently, moderate numbers appear to be arriving to escape harsher weather to our north.

Adult Male Northern Harrier — What could be more appropriate on a foggy, gray evening than finding a “gray ghost” (adult male Northern Harrier) patrolling the fields in search of mice and voles.

If scenes of a January thaw begin to awaken your hopes and aspirations for all things spring, then you’ll appreciate this pair of closing photographs…

Pileated Woodpecker in Silver Maple — The maroon-red flower buds of Silver Maples are beginning to swell. And woodpeckers including Pileated Woodpeckers are beginning to drum, a timber-pounding behavior they use to establish breeding territories in habitats with suitable sites for cavity nesting.

In wet soil surrounding spring seeps and streams, Skunk Cabbage is rising through the leaf litter to herald the coming of a new season. Spring must surely be just around the corner.

January 22, 2024January 22, 2024

Birds Along the River’s Edge

Just as bare ground along a plowed road attracts birds in an otherwise snow-covered landscape, a receding river or large stream can provide the same benefit to hungry avians looking for food following a winter storm.

Here is a small sample of some of the species seen during a brief stop along the Susquehanna earlier this week.

Along vegetated edges of the Susquehanna and its tributaries, the Song Sparrow is ubiquitous in its search for small seeds and other foods. As the river recedes from the effects of this month’s rains, the shoreline is left bare of more recently deposited snow cover. Song Sparrows and other birds are attracted to streamside corridors of frost-free ground to find sufficient consumables for supplying enough energy to survive the long cold nights of winter.

This Golden-crowned Kinglet was observed searching the trees and shrubs along the Susquehanna shoreline for tiny insects and spiders. Temperatures above the bare ground along the receding river can be a few degrees higher than in surrounding snow-covered areas, thus improving the chances of finding active prey among the trunks and limbs of the riparian forest.

Not far from the kinglet, a Brown Creeper is seen searching the bark of a Silver Maple (Acer saccharinum) for wintering insects, as well as their eggs and larvae. Spiders in all their life stages are a favorite too.

American Pipits not only inhabit farm fields during the winter months, they are quite fond of bare ground along the Susquehanna. Seen quite easily along a strip of pebbly shoreline exposed by receding water, these birds will often escape notice when spending time on mid-river gravel and sand bars during periods of low flow.

An American Pipit on a bitterly cold afternoon along the Susquehanna.

January 10, 2024January 18, 2024

Piscivorous Waterfowl Visiting Lakes and Ponds

Heavy rains and snow melt have turned the main stem of the Susquehanna and its larger tributaries into a muddy torrent. For fish-eating (piscivorous) ducks, the poor visibility in fast-flowing turbid waters forces them to seek better places to dive for food. With man-made lakes and ponds throughout most of the region still ice-free, waterfowl are taking to these sources of open water until the rivers and streams recede and clear.

Common Mergansers — The Common Merganser is a species of diving duck with a primary winter range that, along the Atlantic Coast, reaches its southern extreme in the lower Susquehanna and Potomac watersheds. Recently, many have left the main stem of the muddy rivers to congregate on waters with better visibility at some of the area’s larger man-made lakes.

Common Mergansers Feeding — Common Mergansers dive to locate and capture prey, primarily small fish. During this century, their numbers have declined along the southern edge of their winter range, possibly due to birds remaining to the north on open water, particularly on the Great Lakes. In the lower Susquehanna valley, some of these cavity-nesting ducks can now be found year-round in areas where heavy timber again provides breeding sites in riparian forests. After nesting, females lead their young to wander widely along our many miles of larger rivers and streams to feed.

Several Common Mergansers Intimidating a Male with a Freshly Caught Fish — The behavior of these mergansers demonstrates the stiff competition for food that can result when predators are forced away from ideal habitat and become compressed into less favorable space. On the river, piscivores can feed on the widespread abundance of small fish including different species of minnows, shiners, darters, and more. In man-made lakes stocked for recreational anglers with sunfish, bass, and other predators (many of them non-native), small forage species are usually nonexistent. As a result, fish-eating birds can catch larger fish, but are successful far less often. Seen here are several mergansers resorting to intimidation in an effort to steal a young bass away from the male bird that just surfaced with it. While being charged by the aggressors, he must quickly swallow his oversize catch or risk losing it.

With a hard freeze on the way, the fight for life will get even more desperate in the coming weeks. Lakes will ice over and the struggle for food will intensify. Fortunately for mergansers and other piscivorous waterfowl, high water on the Susquehanna is expected to recede and clarify, allowing them to return to their traditional environs. Those with the most suitable skills and adaptations to survive until spring will have a chance to breed and pass their vigor on to a new generation of these amazing birds.

January 3, 2024March 30, 2024

Birds of the Sunny Grasslands

With the earth at perihelion (its closest approach to the sun) and with our home star just 27 degrees above the horizon at midday, bright low-angle light offered the perfect opportunity for doing some wildlife photography today. We visited a couple of grasslands managed by the Pennsylvania Game Commission to see what we could find…

Grasslands and Hedgerows — On this State Game Lands parcel, prescribed fire is used to maintain a mix of grasslands and brushy early successional growth. In nearby areas, both controlled fire and mechanical cutting are used to remove invasive species from hedgerows and the understory of woodlots. Fire tolerant native species then have an opportunity to recolonize the forest and improve wildlife habitat. This management method also reduces the fuel load in areas with the potential for uncontrolled wildfires.

The sun-dried fruits of a Common Persimmon tree found growing in a hedgerow. — The sun-dried fruits of a native Common Persimmon tree found growing in a hedgerow.

Savanna-like Grasslands — Just one year ago, mechanical removal of invasive trees and shrubs (including Multiflora Rose) on this State Game Land was followed by a prescribed fire to create this savanna-like grassland.

White-throated Sparrows were also abundant, but prefer the tangles and shrubs of the thickets.

Northern Mockingbirds were vigilantly guarding winter supplies of berries in the woodlots and hedgerows.

In grasses and tangles on wetter ground, about a dozen Swamp Sparrows were discovered.

Dark-eyed Juncos were encountered only in the vicinity of trees and large shrubs.

Several Savannah Sparrows were observed. Though they’re mostly found in treeless country, this particular one happened to pose atop a clump of shrubs located within, you guessed it, the new savanna-like grasslands.

A tiny bird, even when compared to a sparrow, the Winter Wren often provides the observer with just a brief glimpse before darting away into the cover of a thicket.

Standing Clump of Timber — Within grasslands, scattered stands of live and dead timber can provide valuable habitat for many species of animals.

A "snag" with an excavated nest cavity. — Woodpeckers and other cavity-nesting birds rely upon an abundance of “snags” (standing dead trees) for breeding sites.

This Red-bellied Woodpecker and about a dozen others were found in trees left standing in the project areas.

A Yellow-bellied Sapsucker soaks up some sun.

This very cooperative Pileated Woodpecker seemed to be preoccupied by insect activity on the sun-drenched bark of the trees. This denizen of mature forests will oft times wander into open country where larger lumber is left intact.

Just as things were really getting fun, some late afternoon clouds arrived to dim the already fading daylight. Just then, this Northern Harrier made a couple of low passes in search of mice and voles hidden in the grasses.

December 30, 2023December 31, 2023

Want Healthy Floodplains and Streams? Want Clean Water? Then Make Room for the Beaver

I’m worried about the beaver. Here’s why.

Imagine a network of brooks and rivulets meandering through a mosaic of shrubby, sometimes boggy, marshland, purifying water and absorbing high volumes of flow during storm events. This was a typical low-gradient stream in the valleys of the Lower Susquehanna River Watershed in the days prior to the arrival of the trans-Atlantic human migrant. Then, a frenzy of trapping, tree chopping, mill building, and stream channelization accompanied the east to west waves of settlement across the region. The first casualty: the indispensable lowlands manager, the North American Beaver (Castor canadensis).

Beaver Traps — Nineteenth-century beaver traps on display in the collection of the State Museum of Pennsylvania in Harrisburg. Soon after their arrival, Trans-Atlantic migrants (Europeans) established trade ties to the trans-Beringia migrants (“Indians”) already living in the lower Susquehanna valley and recruited them to cull the then-abundant North American Beavers. By the early 1700s, beaver populations (as well as numbers of other “game” animals) were seriously depleted, prompting the Conoy, the last of the trans-Beringia migrants to reside on the lower Susquehanna, to disperse. The traps pictured here are samples of the types which were subsequently used by the European settlers to eventually extirpate the North American Beaver from the Lower Susquehanna River Watershed during the 1800s.

Without the widespread presence of beavers, stream ecology quickly collapsed. Pristine waterways were all at once gone, as were many of their floral and faunal inhabitants. It was a streams-to-sewers saga completed in just one generation. So, if we really want to restore our creeks and rivers, maybe we need to give the North American Beaver some space and respect. After all, we as a species have yet to build an environmentally friendly dam and have yet to fully restore a wetland to its natural state. The beaver is nature’s irreplaceable silt deposition engineer and could be called the 007 of wetland construction—doomed upon discovery, it must do its work without being noticed, but nobody does it better.

North American Beaver diorama on display in the State Museum of Pennsylvania in Harrisburg. Beavers were reintroduced to the Susquehanna watershed during the second half of the twentieth century.

A beaver dam on a small stream in the Lower Susquehanna River Watershed. — A beaver dam and pond on a small stream in the Lower Susquehanna River Watershed.

Floodplain Wetlands Managed by North American Beavers — Beaver dams not only create ponds, they also maintain shallow water levels in adjacent areas of the floodplain creating highly-functional wetlands that grow the native plants used by the beaver for food. These ecosystems absorb nutrients and sediments. Prior to the arrival of humans, they created some of the only openings in the vast forests and maintained essential habitat for hundreds of species of plants as well as animals including fish, amphibians, reptiles, and birds. Without the beaver, many of these species could not, and in their absence did not, exist here.

The beaver lodge provides shelter from the elements and predators for a family of North American Beavers. — Their newly constructed lodge provides shelter from the elements and from predators for a family of North American Beavers.

Sandhill Cranes Visit a Beaver-managed Floodplain in the lower Susquehanna valley — Floodplains managed by North American Beavers can provide opportunities for the recovery of the uncommon, rare, and extirpated species that once inhabited the network of streamside wetlands that stretched for hundreds of miles along the waterways of the Lower Susquehanna River Watershed.

A wintering Great Blue Heron is attracted to a beaver pond by the abundance of fish in the rivulets that meander through its attached wetlands.

Sora Rail in Beaver Pond — Beaver Ponds and their attached wetlands provide nesting habitat for uncommon birds like this Sora rail.

Wood Duck feeding on Lesser Duckweed in Beaver Pond — Lesser Duckweed grows in abundance in beaver ponds and Wood Ducks are particularly fond of it during their nesting cycle.

Sandhill Cranes feeding among Woolgrass in a Beaver Pond — Beaver dams maintain areas of wet soil along the margins of the pond where plants like Woolgrass sequester nutrients and contain runoff while providing habitat for animals ranging in size from tiny insects to these rare visitors, a pair of Sandhill Cranes (Antigone canadensis).

Sandhill Cranes feeding among Woolgrass in a floodplain maintained by North American Beavers.

Few landowners are receptive to the arrival of North American Beavers as guests or neighbors. This is indeed unfortunate. Upon discovery, beavers, like wolves, coyotes, sharks, spiders, snakes, and so many other animals, evoke an irrational negative response from the majority of people. This too is quite unfortunate, and foolish.

North American Beavers spend their lives and construct their dams, ponds, and lodges exclusively within floodplains—lands that are going to flood. Their existence should create no conflict with the day to day business of human beings. But humans can’t resist encroachment into beaver territory. Because they lack any basic understanding of floodplain function, people look at these indispensable lowlands as something that must be eliminated in the name of progress. They’ll fill them with soil, stone, rock, asphalt, concrete, and all kinds of debris. You name it, they’ll dump it. It’s an ill-fated effort to eliminate these vital areas and the high waters that occasionally inundate them. Having the audacity to believe that the threat of flooding has been mitigated, buildings and poorly engineered roads and bridges are constructed in these “reclaimed lands”. Much of the Lower Susquehanna River Watershed has now been subjected to over three hundred years-worth of these “improvements” within spaces that are and will remain—floodplains. Face it folks, they’re going to flood, no matter what we do to try to stop it. And as a matter of fact, the more junk we put into them, the more we displace flood waters into areas that otherwise would not have been impacted! It’s absolute madness.

By now we should know that floodplains are going to flood. And by now we should know that the impacts of flooding are costly where poor municipal planning and negligent civil engineering have been the norm for decades and decades. So aren’t we tired of hearing the endless squawking that goes on every time we get more than an inch of rain? Imagine the difference it would make if we backed out and turned over just one quarter or, better yet, one half of the mileage along streams in the Lower Susquehanna River Watershed to North American Beavers. No more mowing, plowing, grazing, dumping, paving, spraying, or building—just leave it to the beavers. Think of the improvements they would make to floodplain function, water quality, and much-needed wildlife habitat. Could you do it? Could you overcome the typical emotional response to beavers arriving on your property and instead of issuing a death warrant, welcome them as the talented engineers they are? I’ll bet you could.

November 14, 2023November 15, 2023

Sparrows in the Thicket

As the annual autumn songbird migration begins to reach its end, native sparrows can be found concentrating in fallow fields, early successional thickets, and brushy margins along forest edges throughout the Lower Susquehanna River Watershed.

Brushy Thicket — A streamside thicket composed of seed-producing grasses and wildflowers as well as fruit-bearing shrubs and vines can be ideal habitat for migrating and wintering native sparrows.

Visit native sparrow habitat during mid-to-late November and you have a good chance of seeing these species and more…

The Eastern Towhee is a large native sparrow most often found in early successional growth near woodlands. Look for them in utility right-of-ways.

The elusive Fox Sparrow is a regular late-fall migrant. Few stay for the winter, but northbound birds can be seen as early as mid-February each year.

If you’re lucky enough to live where non-native House Sparrows won’t overrun your bird feeders, you can offer white millet as a supplement to the wild foods these beautiful sparrows might find in your garden sanctuary. Give it a try!

October 5, 2023March 30, 2024

Hymanoptera: A Look at Some Bees, Wasps, Hornets, and Ants

What’s all this buzz about bees? And what’s a hymanopteran? Well, let’s see.

Hymanoptera—our bees, wasps, hornets and ants—are generally considered to be our most evolved insects. Some form complex social colonies. Others lead solitary lives. Many are essential pollinators of flowering plants, including cultivars that provide food for people around the world. There are those with stingers for disabling prey and defending themselves and their nests. And then there are those without stingers. The predatory species are frequently regarded to be the most significant biological controls of the insects that might otherwise become destructive pests. The vast majority of the Hymanoptera show no aggression toward humans, a demeanor that is seldom reciprocated.

Late summer and early autumn is a critical time for the Hymanoptera. Most species are at their peak of abundance during this time of year, but many of the adult insects face certain death with the coming of freezing weather. Those that will perish are busy, either individually or as members of a colony, creating shelter and gathering food to nourish the larvae that will repopulate the environs with a new generation of adults next year. Without abundant sources of protein and carbohydrates, these efforts can quickly fail. Protein is stored for use by the larval insects upon hatching from their eggs. Because the eggs are typically deposited in a cell directly upon the cache of protein, the larvae can begin feeding and growing immediately. To provide energy for collecting protein and nesting materials, and in some cases excavating nest chambers, Hymanoptera seek out sources of carbohydrates. Species that remain active during cold weather must store up enough of a carbohydrate reserve to make it through the winter. Honey Bees make honey for this purpose. As you are about to see, members of this suborder rely predominately upon pollen or insect prey for protein, and upon nectar and/or honeydew for carbohydrates.

We’ve assembled here a collection of images and some short commentary describing nearly two dozen kinds of Hymanoptera found in the Lower Susquehanna River Watershed, the majority photographed as they busily collected provisions during recent weeks. Let’s see what some of these fascinating hymanopterans are up to…

SOLITARY WASPS

A Great Black Wasp on goldenrod (Solidago species). Like other solitary wasps, a female Great Black Wasp will sting and paralyze a host insect upon which she’ll deposit her eggs. After hatching, the larvae will begin consuming the host’s body as a source of protein. The parasitized insects are often katydids or grasshoppers.

A Great Black Wasp. — A Great Black Wasp feeding on nectar, a source of carbohydrates. Unlike social bees and wasps, solitary wasps are equipped with a stinger solely used for immobilizing prey, not defending a nest. They are therefore quite docile and pose little threat to humans.

A Great Black Wasp powdered with pollen. Hymanopterans that gather nectar and/or pollen are tremendously important pollinators of hundreds of species of plants.

Thread-waisted Wasp — A female Thread-waisted wasp (Ammophilia species, probably A. nigricans) drags a paralyzed caterpillar to her excavated nest where she’ll deposit an egg on the body. After hatching, the larval wasp will feed on the disabled caterpillar. The protein will enable the larvae to grow, pupate, and later emerge as an adult wasp.

The female Eastern Cicada Killer (Sphecius speciosus) excavates an underground nest with branch tunnels connecting a dozen chambers or more. As the common name suggests, the female wasp paralyzes a cicada, then makes a strenuous effort to fly and drag it back to the nest for placement in a cell. Each male wasp egg is deposited upon just one immobilized cicada, but a female egg is provided with a cache of several cicadas to provide adequate protein for growth to a larger size. Nest cells are sealed with soil, then the larvae hatch in just a couple of days. Within about two weeks, they have consumed the cicada protein and are fully grown. Wrapped in a cocoon, they spend the winter in the nest, then pupate in the spring before emerging as a new generation of adults.

The Black-and-yellow Mud Dauber (Sceliphron caementarium) builds a mud-ball nest within which it packs paralyzed spiders to function as a source of protein for its larvae.

Pipe Organ Mud Dauber Nest — The Pipe Organ Mud Dauber builds this elaborate nest in which their eggs and paralyzed spiders are deposited in cells sealed with mud partitions. After consuming the spiders, the larvae pupate, overwinter, then emerge from their cells as adults during the following spring. To escape the protection of the nest, the new generation of adults bore through the mud walls. Adult Pipe Organ Mud Daubers resemble the Great Black Wasp, but have a white or yellow distal segment on their rear legs resembling a pair of light-colored socks.

Scavenger Flies in Pipe Organ Mud Dauber Nest — A closeup of the previous image with the lengths of the nest tubes compressed to show four scavenger flies (Miltogramminae), possibly two species, that have invaded this Pipe Organ Mud Dauber nest. Scavenger flies are kleptoparasites that victimize various solitary bees and wasps, depositing larvae directly into the host species’ nest cells to consume the protein cache stored therein.

CUCKOO WASPS

SWEAT BEES

A Sweat Bee (Lasioglossum species). — A Sweat Bee (Lasioglossum species) collecting nectar and pollen on White Snakeroot (Ageratina altissima).

An Augochlorine Green Sweat Bee (Augochlorini). — A female Augochlorine Green Sweat Bee (Augochlorini) collecting nectar on White Snakeroot. Notice the pollen “baskets” on the rear leg.

LEAFCUTTER AND MASON BEES

A Leafcutter Bee (Megachile species). Like Mason Bees, female Mason Bees deposit each of their eggs on a “pollen loaf” within an individual cell inside a preexisting tunnel-like cavity in wood, stone, or in the ground. Unlike Mason Bees, female Leafcutter Bees cut a circular piece of leaf to create each of the cells in their nest. After hatching, the larval bee feeds on the pollen loaf, pupates, then emerges from the shelter of the nest to start a new generation, usually during the following year.

A Leafcutter Bee (Megachile species). — A Leafcutter Bee (Megachile species) visiting Wild Bergamot. Female Leafcutter and Mason Bees lack pollen “baskets” on their rear legs but instead have pollen “brushes” on the underside of the abdomen to gather the protein they need to create a “pollen loaf” for each nest cell.

A Mason Bee (Osmia species) emerging from a nest cell in spring. — A Mason Bee (Osmia species) emerging from a nest in spring. Mason Bees create nesting cells within preexisting cavities in wood, stone, and other other supporting structures. Within the nest cavity, each egg is deposited atop a cache of pollen and nectar, a pollen loaf, then enclosed behind a partition of mud. The female Mason Bee will usually repeat this process until an entire cavity is filled with cells. During the following spring, a new generation of adult Mason Bees digs its way through the cell walls to emerge and repeat the process. These bees readily use paper straws or holes drilled in blocks of wood for nesting.

A mason bee nest box with holes drilled into blocks of wood.

Parasitized Mason Bee Nest — Mason Bees seal each cell and the outer end of their nest cavity with mud. These outer nest cells can been parasitized by a variety of wasps. Here, the outer cell of a Mason Bee nest has been victimized by a tiny chalcid wasp (looks like another one to the lower left). Several species of female chalcid wasps (native Monodontomerus species or non-native Pteromalus venustus) enlarge weak points in the outer partition of a mason bee nest, then sting and paralyze the larval bee inside before depositing their eggs. Within the cell. the wasp larvae consume the larval Mason Bee and the “pollen loaf” provided for its growth. These same parasitic wasps prey upon Leafcutter Bees as well.

BUMBLE BEES, CARPENTER BEES, HONEY BEES, AND DIGGER BEES

A Common Eastern Bumble Bee (Bombus impatiens) collecting nectar and pollen on goldenrod. Bumble bees are our sole native group of social bees. Their wax nests are built in a burrow or other shelter. The eggs are deposited in cells along with a supply of pollen for nourishing the larvae upon hatching. Honey is stored in “honey pots” within the nest. New queens are produced along with male bees during the late-summer and fall. Only the new generation of fertilized queens survive the winter to lay eggs and produce workers to construct a new nest.

A pair of Common Eastern Bumble Bees collecting nectar and becoming dusted with pollen. Their fuzzy coats and semi-warm-blooded metabolism allows them to be active in cooler weather than is tolerated by other bees.

A Common Eastern Bumble Bee pollinating a Great Rhododendron flower. — Flowering plants including the Great Rhododendron find success attracting pollinators to their reproductive blossoms by offering carbohydrate-rich nectar to insects like this Eastern Bumble Bee. The yellow spots on the flower’s upper petal help to guide visitors toward their sweet treat.

An Eastern Carpenter Bee feeding on goldenrod nectar. Compare the almost hairless abdomen to that of the bumble bees. Carpenter bees are semi-social insects. Females lay their eggs in cells within galleries bored into wood. These nests are completed with great precision, avoiding creation of any second entrance by mistakenly breaching the outer surface of the excavated wood. Each egg/larvae is provided with a supply of protein-rich pollen. Males often hover outside their mate’s nest to prevent competing males from entering the area.

A Honey Bee visiting goldenrod alongside Common Eastern Bumble Bees. — A worker Honey Bee, a female member of a sisterhood of foragers from a nearby hive, visits goldenrod alongside Common Eastern Bumble Bees. Honey Bees were brought to North America during the 1620s, the earliest years of the trans-Atlantic migration of European colonists, to pollinate cultivated plants and to provide a reliable source of honey and beeswax. Within the Honey Bee’s social structure, the queen of each hive lays the eggs to produce the female worker bees. Once each year, male drones are produced along with a new generation of queens.

Honey Bee Hive — In nature, Honey Bees build hives in tree cavities. Recently, this colony constructed a hive in a screech owl nest box at susquehannawildlife.net headquarters. To provide protein for the hatching larvae, worker bees collect pollen and deposit it within the hexagonal cells of the vertically aligned beeswax combs. After an egg is deposited upon the pollen cache, each cell is sealed with more beeswax. Young females tend these nest combs before maturing and becoming foraging worker bees.

Bee Hive Display — In apiculture, Honey Bees are raised in man-made hives. This Pennsylvania Association of Beekeepers display gives visitors to the Pennsylvania Farm Show in Harrisburg a look at the inner workings of a live bee hive. Nectar collected by worker bees is turned into honey to provide the supply of carbohydrates needed to fuel the colony through the winter. Note the honeycombs on the glass.

A possible Small Carpenter Bee Ceratina species). — A possible Small Carpenter Bee (Ceratina species) visiting White Snakeroot. Small Carpenter Bees nest inside hollow stems and twigs. Some species are eusocial, with a queen’s daughters and sisters sharing responsibility for finding food and rearing the young. Females overwinter inside a one of the excavated stems and begin a new nest there in the spring.

A Digger Bee (possibly Melissodes species). — A Digger Bee (possibly Melissodes species) with “pollen baskets” full of pollen collected from nearby flowers. Digger Bees in the genus Melissodes are often known as the Long-horned Bees. These social insects excavate underground nests and many species practice communal living.

SCOLIID WASPS

The Two-spotted Scoliid Wasp (Scolia dubia), also known as the Blue-winged Scoliid Wasp, is most frequently observed feeding on nectar. Scoliid wasps are solitary nesters, though they may assemble into groups while visiting flowers. They often ignore the presence of humans and are seldom disturbed by their presence. Females seek out the burrowing grubs of beetles including the Green June Bug (Cotinis nitida) and possibly the Japanese Beetle. After stinging a grub to paralyze it, the wasp will deposit her egg on its body, then bury it. Upon hatching, the larval wasp will feed on the grub for nourishment as it grows.

June Bugs eating watermelon. — Don’t like having your watermelon overrun by Green June Bugs while you’re eating? Then you ought to go out of your way to be nice to the Two-spotted Scoliid Wasp.

The Double-banded Scoliid (Scolia bicincta) parasitizes beetle larvae as hosts for its larvae. For carbohydrates it relishes flower nectar.

PAPER WASPS

A Northern Paper Wasp (Polistes fuscatus). Paper wasps prey upon numerous garden pests, particularly caterpillars, to collect protein. Though they are social insects equipped with stingers to subdue their victims and defend their nests, paper wasps are surprisingly docile.

The Northern Paper Wasp — A Northern Paper Wasp (Polistes fuscatus) feeding on nectar from a goldenrod flower.

A Northern Paper Wasp harvesting wood pulp from the side of a mason bee nest box at susquehannawildlife.net headquarters. The pulp is chewed in the wasp’s saliva to create the paper used to construct the colony’s open-cell nest.

Guinea Paper Wasps (Polistes exclamans) at their nest. — Common Paper Wasps (Polistes exclamans), also known as Guinea Paper Wasps, at their open-cell nest. This and the nests of most other paper wasps are suspended on a filament or a pedicle. Many paper wasps can excrete an ant repellent on this section of the nest in an effort to prevent invasion. Like many other social hymenopterans, a defending wasp can secrete a pheromone venom during the stinging process to warn the colony of danger at the nest. In winter, Common Paper Wasps seek shelter in stumps and other locations to hibernate.

The European Paper Wasp (Polistes dominula) is a non-native species which builds nests in man-made structures including bird houses. To collect protein, they prey on a wide selection of insects and other invertebrates. As such, European Paper Wasps are widespread and successful here in North America.

YELLOWJACKETS AND HORNETS

An Eastern Yellowjacket feeding on lanternfly honeydew. Eastern Yellowjackets derive much of their success from being generalists, collecting carbohydrates from nearly any sweet source, natural or man made. They are quite fond of ripe fruits, flower nectar, and sugary snacks and drinks, especially soda. Protein for nourishing their larvae is derived from the wide variety invertebrates upon which they prey and from carrion. These foods are chewed into a paste form in preparation for placement into the brood cells.

Robber Fly consuming an Eastern Yellowjacket — Yellowjackets may be moody and aggressive, but they do fall victim to a number of predators. A Robber Fly (Promachus species) has taken down and is devouring this Eastern Yellowjacket.

A Bald-faced Hornet (Dolichovespula maculata) feeding on Spotted Lanternfly honeydew deposits — A Bald-faced Hornet (Dolichovespula maculata) feeding on Spotted Lanternfly honeydew on a Tree-of-heaven (Ailanthus altissima). In the absence of nectar-producing flowers, many bees, yellowjackets, and hornets have turned to the invasive lanternfly and Ailanthus combo to turn the sun’s energy into the carbohydrates they need. For protein, they prey upon spiders, flies, caterpillars, and a variety of other insects.

A Bald-faced Hornet collecting wood pulp from the surface of a weathered picnic table. — To create paper for nest construction, this Bald-faced Hornet is collecting wood pulp from the surface of a weathered picnic table. Away from the nest, these hornets demonstrate a calm, carefree demeanor and can be closely observed.

Bald-faced Hornet Nest — A Bald-faced Hornet nest in a pine tree. These hives are strictly temporary. Within the nest, a generation of drones (males) and new queens are produced late each year. These wasps leave the colony to mate. With the arrival of freezing weather, all inhabitants within the nest, including the old queen, perish, as do the drones that departed to breed. Only the new queens survive winter hibernation to propagate the next generation of wasps, starting with the workers needed to construct a fresh nest and reestablish the colony.

Bald-faced Hornets Peering from Nest — Did you ever get the feeling you’re being watched? Don’t go messing around with Bald-faced Hornet nests. The occupants therein, like other social bees, wasps, and hornets, are equipped with stingers and venom for defending their colony. This is an adaptation that has developed over time to assure the survival of populations of these insects. Think about it this way, a solitary wasp that loses a nest loses only their individual brood of offspring. There is minimal impact on the wider local population of such insects. Conversely, a social wasp or hornet that loses a nest loses an entire colony, possibly negating the benefits of their cooperative behavior and threatening the survival of the species. Insects that cooperate to build societies for survival can be more vulnerable to the catastrophic impacts of certain circumstances like disease, weather, and invasion of their colonies. Therefore, natural selection has provided them with contingencies for these dangers, for example, the instinct to construct protective shelters and the adaptation of stingers and venom for defense against intruders and would-be predators. Oh, and by the way, the Bald-faced Hornet can spray venom, often aiming for the eyes, so keep your distance.

European Hornets (Vespa crabro), an introduced species, are predatory on a variety of flying insects for protein. For carbohydrates they are attracted to sweets like this lanternfly honeydew on Tree-of-heaven.

European Hornets constructing a nest in a tree cavity. — European Hornets constructing a paper nest in a tree cavity.

POTTER WASPS

A Potter Wasp (Eumenes species, probably E. fraturnus) hovering near a European Paper Wasp. — A potter wasp (Eumenes species), probably a Fraternal Potter Wasp (E. fraternus), hovering near a European Paper Wasp on Partridge Pea. The female potter wasp builds a small mud nest resembling a tiny clay pot. One of her eggs is inserted and left hanging on a thin thread. Then a paralyzed caterpillar is deposited as a source of protein to nourish the larva upon hatching. Lastly, the pot is sealed with a lid made of wet mud. Upon maturing, the new generation of adult wasps perform a pottery breaking to emerge and take flight.

ANTS

We hope this brief but fascinating look at some of our more common bees, wasps, hornets, and ants has provided the reader with an appreciation for the complexity with which their food webs and ecology have developed over time. It should be no great mystery why bees and other insects, particularly native species, are becoming scarce or absent in areas of the Lower Susquehanna River Watershed where the landscape is paved, hyper-cultivated, sprayed, mowed, and devoid of native vegetation, particularly nectar-producing plants. Late-summer and autumn can be an especially difficult time for hymanopterans seeking the sources of proteins and carbohydrates needed to complete preparations for next year’s generations of these valuable insects. An absence of these staples during this critical time of year quickly diminishes the diversity of species and begins to tear at the fabric of the food web. This degradation of a regional ecosystem can have unforeseen impacts that become increasingly widespread and in many cases permanent.

A farmland desert. — How can anyone be surprised by the absence of bees and other pollinators in farmland? Manicured and cultivated ground offers little in the way of year-round shelter and food sources for insects and other wildlife.

A savanna-like habitat. — This savanna-like habitat on a south-facing slope provides the abundance of nectar-producing, pollen-rich wildflowers needed to nourish a diverse population of insects including bees, wasps, hornets, and ants. Goldenrods, asters, and White Snakeroot are some of their late-season favorites.

Editor’s Note: No bees, wasp, hornets, or ants were harmed during this production. Neither was the editor swarmed, attacked, or stung. Remember, don’t panic, just observe.

SOURCES

Eaton, Eric R., and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Company. New York, NY.

(If you’re interested in insects, get this book!)

September 24, 2023September 27, 2023

Four Common Grasshoppers

Grasshoppers are perhaps best known for the occasions throughout history when an enormous congregation of these insects—a “plague of locusts”—would assemble and rove a region to feed. These swarms, which sometimes covered tens of thousands of square miles or more, often decimated crops, darkened the sky, and, on occasion, resulted in catastrophic famine among human settlements in various parts of the world.

The largest “plague of locusts” in the United States occurred during the mid-1870s in the Great Plains. The Rocky Mountain Locust (Melanoplus spretus), a grasshopper of prairies in the American west, had a range that extended east into New England, possibly settling there on lands cleared for farming. Rocky Mountain Locusts, aside from their native habitat on grasslands, apparently thrived on fields planted with warm-season crops. Like most grasshoppers, they fed and developed most vigorously during periods of dry, hot weather. With plenty of vegetative matter to consume during periods of scorching temperatures, the stage was set for populations of these insects to explode in agricultural areas, then take wing in search of more forage. Plagues struck parts of northern New England as early as the mid-1700s and were numerous in various states in the Great Plains through the middle of the 1800s. The big ones hit between 1873 and 1877 when swarms numbering as many as trillions of grasshoppers did $200 million in crop damage and caused a famine so severe that many farmers abandoned the westward migration. To prevent recurrent outbreaks of locust plagues and famine, experts suggested planting more cool-season grains like winter wheat, a crop which could mature and be harvested before the grasshoppers had a chance to cause any significant damage. In the years that followed, and as prairies gave way to the expansive agricultural lands that presently cover most of the Rocky Mountain Locust’s former range, the grasshopper began to disappear. By the early years of the twentieth century, the species was extinct. No one was quite certain why, and the precise cause is still a topic of debate to this day. Conversion of nearly all of its native habitat to cropland and grazing acreage seems to be the most likely culprit.

The critically endangered Eskimo Curlew (Numenius borealis), a species not photographed since 1962 and not confirmed since 1963, fed on Rocky Mountain Locusts during its spring migration through the Great Plains. Excessive hunting and conversion of grasslands to agriculture are believed responsible for the bird’s demise. (United States Fish and Wildlife Service image by Christina Nelson)

In the Mid-Atlantic States, the mosaic of the landscape—farmland interspersed with a mix of forest and disturbed urban/suburban lots—prevents grasshoppers from reaching the densities from which swarms arise. In the years since the implementation of “Green Revolution” farming practices, numbers of grasshoppers in our region have declined. Systemic insecticides including neonicotinoids keep grasshoppers and other insects from munching on warm-season crops like corn and soybeans. And herbicides including 2,4-D (2,4-Dichlorophenoxyacetic acid) have, in effect, become the equivalent of insecticides, eliminating broadleaf food plants from the pasturelands and hayfields where grasshoppers once fed and reproduced in abundance. As a result, few of the approximately three dozen species of grasshoppers with ranges that include the Lower Susquehanna River Watershed are common here. Those that still thrive are largely adapted to roadsides, waste ground, and small clearings where native and some non-native plants make up their diet.

Here’s a look at four species of grasshoppers you’re likely to find in disturbed habitats throughout our region. Each remains common in relatively pesticide-free spaces with stands of dense grasses and broadleaf plants nearby.

CAROLINA GRASSHOPPER

Dissosteira carolina

Carolina Grasshopper wing — The Carolina Grasshopper is most readily detected and identified when it flies. The colors of the wings resemble those of the Mourning Cloak butterfly.

Great Black Wasp on goldenrod. — Carolina Grasshoppers are among the preferred victims of Great Black Wasps (Sphex pensylvanicus). A female wasp stings the grasshopper to paralyze it, then drags it away to one of numerous cells in an underground burrow where she lays an egg on it. The body of the disabled grasshopper then provides nourishment for the larval wasp.

DIFFERENTIAL GRASSHOPPER

Melanoplus differentialis

An adult female Differential Grasshopper with fully developed wings.

An adult female Differential Grasshopper

TWO-STRIPED GRASSHOPPER

Melanoplus bivittatus

An adult female Two-striped Grasshopper.

RED-LEGGED GRASSHOPPER

Melanoplus femurrubrum

The Red-legged Grasshopper may currently be our most abundant and widespread species.

Protein-rich grasshoppers are an important late-summer, early-fall food source for birds. The absence of these insects has forced many species of breeding birds to abandon farmland or, in some cases, disappear altogether.

During the mid-twentieth century, the Cattle Egret (Bubulcus ibis), a notoriously nomadic species, transited the Atlantic from Africa to colonize the Americas…and they did it without any direct assistance from humans. During the 1970s and early 1980s, a nesting population of Cattle Egrets on river islands adjacent to the Susquehanna’s Conejohela Flats off Washington Boro was the largest inland rookery in the northeastern United States. The Lancaster County Bird Club censused the birds each August and found peak numbers in 1981 (7,580). During their years of abundance, V-shaped flocks of Cattle Egrets from the rookery islands ventured into grazing lands throughout portions of Lancaster, York, Dauphin, and Lebanon Counties to hunt grasshoppers. These daily flights were a familiar summertime sight for nearly two decades. Then, in the early 1980s, reductions in pastureland acreage and plummeting grasshopper numbers quickly took their toll. By 1988, the rookery was abandoned. The Cattle Egrets had moved on. (Vintage 33 mm image)

To the delight of Wild Turkeys, each of the four species of grasshoppers shown above frequents clearings and roadsides adjacent to forest areas. While changes in grasshopper distribution have been detrimental to populations of birds like pheasants, they’ve created a feeding bonanza for turkeys.

Wild Turkeys feeding on grasshoppers along a forest road. — Wild Turkeys feeding on an abundance of grasshoppers along a forest road.

American Kestrel Feeding on Grasshopper — An American Kestrel feeds on a grasshopper while ignoring the abundance of Spotted Lanternflies swarming the adjacent utility pole. In Susquehanna valley farmlands, grasshopper and kestrel numbers are down. Lanternflies, on the other hand, have got it made.

September 11, 2023September 12, 2023

A Visit to a Beaver Pond

To pass the afternoon, we sat quietly along the edge of a pond created recently by North American Beavers (Castor canadensis). They first constructed their dam on this small stream about five years ago. Since then, a flourishing wetland has become established. Have a look.

A beaver lodge. — The beaver lodge was built among shrubs growing in shallow water in the middle of the pond.

Woolgrass in a beaver pond. — Woolgrass (Scirpus cyperinus) is a bulrush that thrives as an emergent and as a terrestrial plant in moist soils bordering the pond.

A male Common Whitetail dragonfly keeping watch over his territory.

A Twelve-spotted Skimmer perched on Soft Rush.

A Blue Dasher dragonfly seizing a Fall Field Cricket (Gryllus pennsylvanicus).

A Spicebush Swallowtail visiting Cardinal Flower. — A Spicebush Swallowtail visiting a Cardinal Flower.

A Green Heron looking for small fish, crayfish, frogs, and tadpoles.

A Green Heron stalks potential prey. — The Green Heron stalking potential prey.

A Wood Duck feeding on Lesser Duckweed. — A Wood Duck feeding on the tiny floating plant known as Lesser Duckweed (Lemna minor).

A Least Sandpiper feeding along the muddy edge of a beaver pond. — A Least Sandpiper poking at small invertebrates along the muddy edge of the beaver pond.

A Solitary Sandpiper testing the waters for proper feeding depth.

A Pectoral Sandpiper searches for its next morsel of sustenance.

A Sora rail in a beaver pond. — The Sora (Porzana carolina) is a seldom seen rail of marshlands including those created by North American Beavers. Common Cattails, sedges, and rushes provide these chicken-shaped wetland birds with nesting and loafing cover.

Isn’t that amazing? North American Beavers build and maintain what human engineers struggle to master—dams and ponds that reduce pollution, allow fish passage, and support self-sustaining ecosystems. Want to clean up the streams and floodplains of your local watershed? Let the beavers do the job!

August 28, 2023September 7, 2023

Shorebirds on the Mud in York County, Pennsylvania

At Lake Redman just to the south of York, Pennsylvania, a draw down to provide drinking water to the city while maintenance is being performed on the dam at neighboring Lake Williams, York’s primary water source, has fortuitously coincided with autumn shorebird migration. Here’s a sample of the numerous sandpipers and plovers seen today on the mudflats that have been exposed at the southeast end of the lake…

Least Sandpiper at Lake Redman, York County, Pennsylvania. — One of a hundred or more Least Sandpipers seen on mudflats at Lake Redman today.

A Semipalmated Plover and a Least Sandpiper at Lake Redman, York County, Pennsylvania. — A Semipalmated Plover and a Least Sandpiper

Pectoral Sandpipers at Lake Redman, York County, Pennsylvania. — Pectoral Sandpipers.

A Pectoral Sandpiper and Least Sandpipers at Lake Redman, York County, Pennsylvania. — A Pectoral Sandpiper and two Least Sandpipers.

A Semipalmated Sandpiper at Lake Redman, York County, Pennsylvania. — A Semipalmated Sandpiper.

A Stilt Sandpiper at Lake Redman, York County, Pennsylvania. — A Stilt Sandpiper feeding.

Stilt Sandpiper consuming an edible at Lake Redman, York County, Pennsylvania. — Stilt Sandpiper consuming an edible.

Stilt Sandpiper at rest at Lake Redman, York County, Pennsylvania. — Stilt Sandpiper at rest.

A Solitary Sandpiper at Lake Redman, York County, Pennsylvania. — A Solitary Sandpiper

A Lesser Yellowlegs at Lake Redman, York County, Pennsylvania. — A Lesser Yellowlegs.

A Greater Yellowlegs at Lake Redman, York County, Pennsylvania. — A Greater Yellowlegs.

Osprey at Lake Redman, York County, Pennsylvania. — Stirring up the shorebird crowd every now and then were several Ospreys, but all would soon be back to the business of feeding in the mud.

An Osprey hovers above shallow water near the mudflats as it searches for fish.

Not photographed but present at Lake Redman were at least two additional species of shorebirds, Killdeer and Spotted Sandpiper—bringing the day’s tally to ten. Not bad for an inland location! It’s clearly evident that these waders overfly the lower Susquehanna valley in great numbers during migration and are in urgent need of undisturbed habitat for making stopovers to feed and rest so that they might improve their chances of surviving the long journey ahead of them. Mud is indeed a much needed refuge.

August 22, 2023September 7, 2023

One of Nature’s Finest: The Cardinal Flower

It may be one of the most treasured plants among native landscape gardeners. The Cardinal Flower (Lobelia cardinalis) blooms in August each year with a startling blaze of red color that, believe it or not, will sometimes be overlooked in the wild.

Cardinal Flower on a Stream — Cardinal Flower is most often found in wet soil along forested bodies of water. The blooms of this shade-loving species may go unnoticed until rays of sunshine penetrate the canopy to strike their brilliant red petals.

The Cardinal Flower grows in wetlands as well as in a variety of moist soils along streams, rivers, lakes, and ponds. Shady locations with short periods of bright sun each day seem to be favored for an abundance of color.

Cardinal Flower and Great Blue Lobelia — Cardinal Flower in bloom in a riparian forest along the Susquehanna. To its right is its close relative, Great Lobelia, a plant sometimes known as Great Blue Lobelia or Blue Cardinal Flower.

Cardinal Flower in a wet bottomland woods.

The Cardinal Flower can find favorable growing conditions along stream, river and lake shores. — The Cardinal Flower can find favorable growing conditions along stream, river, and lake shores. Even though they are perennial plants, their presence along such waters often seems temporary. Changing conditions cause them to suddenly disappear from known locations, then sometimes reappear at the same place or elsewhere nearby. Some of this phenomenon may be due to the fact that stressed plants can fail to bloom, so they easily escape notice. When producing flowers during favorable years, the plants seem to mysteriously return.

Cardinal Flowers along a wave-swept shoreline light up the greenery of erosion-controlling riparian vegetation with glowing red color.

The Cardinal Flower can be an ideal plant for attracting hummingbirds, bees, butterflies, and other late-summer pollinators. It grows well in damp ground, especially in rain gardens and along the edges streams, garden ponds, and stormwater retention pools. If you’re looking to add Cardinal Flower to your landscape, you need first to…

REMEMBER the CARDINAL RULE…

Cardinal Flower plants are available at many nurseries that carry native species of garden and/or pond plants. Numerous online suppliers offer seed for growing your own Cardinal Flowers. Some sell potted plants as well. A new option is to grow Cardinal Flowers from tissue cultures. Tissue-cultured plants are raised in laboratory media, so the pitfalls of disease and hitchhikers like invasive insects and snails are eliminated. These plants are available through the aquarium trade from most chain pet stores. Though meant to be planted as submerged aquatics in fish tank substrate, we’ve reared the tissue-cultured stock indoors as emergent plants in sandy soil and shallow water through the winter and early spring. When it warms up, we transplant them into the edges of the outdoor ponds to naturalize. As a habit, we always grow some Cardinal Flower plants in the fish tanks to take up the nitrates in the water and to provide a continuous supply of cuttings for starting more emergent stock for outdoor use.

Tissue culture Cardinal Flower being grown as a submerged aquatic in a fish aquarium. — A tissue-cultured Cardinal Flower rooted in sandy substrate and being grown as a submerged aquatic plant in a fish tank. Cuttings from this plant will be used to grow emergent specimens in shallow water for transplanting outdoors around the garden pond.

Cardinal Flower from Tissue Culture — A Cardinal Flower grown from an aquarium store tissue culture blooms in the pond at susquehannawildlife.net headquarters.

Cardinal Flower blooming in November. — Grown as an emergent, Cardinal Flower may bloom very late in the season. This tissue-cultured specimen in the headquarters pond was photographed in early November, 2022.

August 10, 2023August 14, 2023

Butterflies and More at Boyd Big Tree Preserve Conservation Area

If you’re feeling the need to see summertime butterflies and their numbers just don’t seem to be what they used to be in your garden, then plan an afternoon visit to the Boyd Big Tree Preserve along Fishing Creek Valley Road (PA 443) just east of U.S. 22/322 and the Susquehanna River north of Harrisburg. The Pennsylvania Department of Conservation and Natural Resources manages the park’s 1,025 acres mostly as forested land with more than ten miles of trails. While located predominately on the north slope of Blue Mountain, a portion of the preserve straddles the crest of the ridge to include the upper reaches of the southern exposure.

American Chestnut at Boyd Big Tree Preserve — A grove of American Chestnuts (Castanea dentata) planted at Boyd Big Tree Preserve is part of a propagation program working to restore blight-resistant trees to Pennsylvania and other areas of their former range which included the Appalachians and the upper Ohio River watershed.

Fortunately, one need not take a strenuous hike up Blue Mountain to observe butterflies. Open space along the park’s quarter-mile-long entrance road is maintained as a rolling meadow of wildflowers and cool-season grasses that provide nectar for adult butterflies and host plants for their larvae.

Butterfly Meadow at Boyd Big Tree Preserve — A view looking north at the butterfly meadow and entrance road at Boyd Big Tree Preserve Conservation Area. Second Mountain is in the background.

Walking a Meadow Path — Mowed paths follow the entrance road and a portion of the perimeter of the meadow allowing visitors a chance to wander among the waist-high growth to see butterflies, birds, and blooming plants at close range without trampling the vegetation or risking exposure to ticks.

A Silver-spotted Skipper feeding on nectar from Dogbane (Apocynum cannabinum) flowers. — A Silver-spotted Skipper feeding on nectar from the flowers of Indian Hemp (Apocynum cannabinum). Like the milkweeds, Indian Hemp is a member of the dogbane family (Apocynaceae).

An Eastern Tiger Swallowtail feeding on Common Milkweed.

Great Spangled Fritillary on Common Milkweed. — A Great Spangled Fritillary (Speyeria cybele) on Common Milkweed.

A Black Swallowtail feeding on Common Milkweed nectar. — A Black Swallowtail (Papilio polyxenes) feeding on Common Milkweed nectar.

A Pipevine Swallowtail on Common Milkweed. — A Pipevine Swallowtail (Battus philenor) on Common Milkweed.

A Pipevine Swallowtail on visiting Butterfly Weed. — A Pipevine Swallowtail visiting the brilliant blooms of Butterfly Weed, a favorite of a wide variety of pollinators.

A Black Swallowtail on Butterfly Weed — A Black Swallowtail with damaged wings alights atop a Butterfly Weed flower cluster. Note the pair of parallel rows of red-orange spot on the underside of the hindwing.

A Monarch on Butterfly Weed — A Monarch feeding on nectar from the flowers of Butterfly Weed.

A mating pair of Eastern Tailed Blues. — A mating pair of Eastern Tailed Blues on a Timothy (Phleum pratense) spike.

A female (left) and male Great Spangled Fritillary. — A male Great Spangled Fritillary (right) pursuing a female.

Butterflies aren’t the only colorful insects patrolling the meadows at Boyd Big Tree Preserve. Dragonflies including Common Green Darners are busily pursuing prey, particularly small flying insects like mosquitos, gnats, and flies.

Juvenile Broad-winged Hawk — Dragonflies themselves can become prey and are much sought after by Broad-winged Hawks. This very vocal juvenile gave us several good looks as it ventured from the forest into the skies above the upper meadow during midday. It wasn’t yet a good enough flier to snag a dragonfly, but it will have plenty of opportunities for practice during its upcoming fall migration which, for these Neotropical raptors, will get underway later this month.

Do yourself a favor and take a trip to the Boyd Big Tree Preserve Conservation Area. Who knows? It might actually inspire you to convert that lawn or other mowed space into much-needed butterfly/pollinator habitat.

While you’re out, you can identify your sightings using our photographic guide—Butterflies of the Lower Susquehanna River Watershed—by clicking the “Butterflies” tab at the top this page. And while you’re at it, you can brush up on your hawk identification skills ahead of the upcoming migration by clicking the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab. Therein you’ll find a listing and descriptions of hawk watch locations in and around the lower Susquehanna region. Plan to visit one or more this autumn!

July 30, 2023August 25, 2023

Some Good Reasons to Postpone Mowing Until Mid-August

Here in a series of photographs are just a handful of the reasons why the land stewards at Middle Creek Wildlife Management Area and other properties where conservation and propagation practices are employed delay the mowing of fields composed of cool-season grasses until after August 15 each year.

Eastern Meadowlarks, birds of large pastures, hay lots and other meadows of cool-season grasses, build their nests and raise their young on the ground. In the years since the early twentieth century, loss in the volume of acreage maintained in the lower Susquehanna Valley as grassland habitat types has dramatically reduced the prevalence and abundance of this and other birds with similar nesting requirements. During the most recent fifty years, early and frequent mowing and other practices introduced as part of agriculture’s Green Revolution have all but eliminated ground-nesting grassland species from the region.

The Bobolink, like the meadowlark, is a member of the blackbird family (Icteridae). It too requires grasslands free of disturbances like mowing for the duration of the nesting season which, for this particular bird, lasts until mid-August in the lower Susquehanna region. In places lacking their specific habitat requirements, Bobolinks will seldom be detected except as flyovers during migration.

At places like Middle Creek Wildlife Management Area where a mix of grasslands, early successional growth, and even some cropland are maintained, the Blue Grosbeak has extended its range well north of the Mason-Dixon and has become a regular nesting species during recent decades. Good habitat management does pay dividends.

Right now is a good time to visit Middle Creek Wildlife Management Area to see the effectiveness a delayed mowing schedule can have when applied to fields of cool-season grasses. If you slowly drive, walk, or bicycle the auto tour route on the north side of the lake, you’ll pass through vast areas maintained as cool-season and warm-season grasses and early successional growth—and you’ll have a chance to see these and other grassland birds raising their young. It’s like a trip back in time to see farmlands they way they were during the middle years of the twentieth century.

July 24, 2023August 25, 2023

Shorebirds and More at Bombay Hook National Wildlife Refuge

Have you purchased your 2023-2024 Federal Duck Stamp? Nearly every penny of the 25 dollars you spend for a duck stamp goes toward habitat acquisition and improvements for waterfowl and the hundreds of other animal species that use wetlands for breeding, feeding, and as migration stopover points. Duck stamps aren’t just for hunters, purchasers get free admission to National Wildlife Refuges all over the United States. So do something good for conservation—stop by your local post office and get your Federal Duck Stamp.

2023-2024 Federal Duck Stamp. Your Federal Duck Stamp is your free pass to visit the nation's National Wildlife Refuges including Bombay Hook National Wildlife Refuge on Delaware Bay near Smyrna, Delaware. — Your Federal Duck Stamp is your admission ticket for entry into many of the country’s National Wildlife Refuges including Bombay Hook National Wildlife Refuge on Delaware Bay near Smyrna, Delaware.

Still not convinced that a Federal Duck Stamp is worth the money? Well then, follow along as we take a photo tour of Bombay Hook National Wildlife Refuge. Numbers of southbound shorebirds are on the rise in the refuge’s saltwater marshes and freshwater pools, so we timed a visit earlier this week to coincide with a late-morning high tide.

This pair of Northern Bobwhite, a species now extirpated from the Lower Susquehanna River Watershed and the rest of Pennsylvania, escorted us into the refuge. At Bombay Hook, they don’t waste your money mowing grass. Instead, a mosaic of warm-season grasses and early successional growth creates ideal habitat for Northern Bobwhite and other wildlife.

Shearness Pool at Bombay Hook N.W.R. — Twice each day, high tide inundates mudflats in the saltwater tidal marshes at Bombay Hook prompting shorebirds to move into the four man-made freshwater pools. Birds there can often be observed at close range. The auto tour route through the refuge primarily follows a path atop the dikes that create these freshwater pools. Morning light is best when viewing birds on the freshwater side of the road, late-afternoon light is best for observing birds on the tidal saltwater side.

Semipalmated Sandpipers stream into Raymond Pool to escape the rising tide in the salt marsh.

Semipalmated Sandpipers and Short-billed Dowitcher — More Semipalmated Sandpipers and a single Short-billed Dowitcher (Limnodromus griseus) arrive at Raymond Pool.

Two more Short-billed Dowitchers on the way in.

Sandpipers, Avocets, Egrets, and Mallards — Recent rains have flooded some of the mudflats in Bombay Hook’s freshwater pools. During our visit, birds were often clustered in areas where bare ground was exposed or where water was shallow enough to feed. Here, Short-billed Dowitchers in the foreground wade in deeper water to probe the bottom while Semipalmated Sandpipers arrive to feed along the pool’s edge. Mallards, American Avocets, and egrets are gathered on the shore.

Semipalmated Sandpipers, Short-billed Dowitchers, and Forster's Terns — Hundreds of Semipalmated Sandpipers, several Short-billed Dowitchers, and some Forster’s Terns (Sterna forsteri) crowd onto a mud bar at Bear Swamp Pool.

Semipalmated Sandpipers, Forster's Terns, and a Short-billed Dowitcher — A zoomed-in view of the previous image showing a tightly packed crowd of Semipalmated Sandpipers, Forster’s Terns, and a Short-billed Dowitcher (upper left).

Short-billed Dowitchers, American Avocets, and a Snowy Egret in Raymond Pool. A single Stilt Sandpiper (Calidris himantopus) can been seen flying near the top of the flock of dowitchers just below the egret.

Stilt Sandpiper among Short-billed Dowitchers — Zoomed-in view of a Stilt Sandpiper (Calidris himantopus), the bird with white wing linings.

American Avocets probe the muddy bottom of Raymond Pool.

Dunlin and Short-billed Dowitchers — Among these Short-billed Dowitchers, the second bird from the bottom is a Dunlin. This sandpiper, still in breeding plumage, is a little bit early. Many migrating Dunlin linger at Bombay Hook into October and even November.

This Least Sandpiper found a nice little feeding area all to itself at Bear Swamp Pool.

A Greater Yellowlegs at Bear Swamp Pool.

Marsh Wren singing — The chattering notes of the Marsh Wren’s (Cistothorus palustris) song can be heard along the tour road wherever it borders tidal waters.

Marsh Wren Nest — This dome-shaped Marsh Wren nest is supported by the stems of Saltwater Cordgrass (Sporobolus alterniflorus), a plant also known as Smooth Cordgrass. High tide licks at the roots of the cordgrass supporting the temporary domicile.

By far the most common dragonfly at Bombay Hook is the Seaside Dragonlet (Erythrodiplax berenice). It is our only dragonfly able to breed in saltwater. Seaside Dragonlets are in constant view along the impoundment dikes in the refuge.

Red-winged Blackbirds are still nesting at Bombay Hook, probably tending a second brood.

Mute Swans and Canada Geese — Non-native Mute Swans and resident-type Canada Geese in the rain-swollen Shearness Pool.

A pair of Trumpeter Swans (Cygnus buccinator) as seen from the observation tower at Shearness Pool. Unlike gregarious Tundra and Mute Swans, pairs of Trumpeter Swans prefer to nest alone, one pair to a pond, lake, or sluggish stretch of river. The range of these enormous birds was restricted to western North America and their numbers were believed to be as low as 70 birds during the early twentieth century. An isolated population consisting of several thousand birds was discovered in a remote area of Alaska during the 1930s allowing conservation practices to protect and restore their numbers. Trumpeter Swans are slowly repopulating scattered east coast locations following recent re-introduction into suitable habitats in the Great Lakes region.

A hen Wood Duck (second from right) escorts her young. — Wood Ducks in Bear Swamp Pool.

Black-necked Stilt and young. — A Bombay Hook N.W.R. specialty, a Black-necked Stilt and young at Bear Swamp Pool.

As the tide recedes, shorebirds leave the freshwater pools to begin feeding on the vast mudflats exposed within the saltwater marshes. Most birds are far from view, but that won’t stop a dedicated observer from finding other spectacular creatures on the bay side of the tour route road.

Tidal Marshes — Bombay Hook National Wildlife Refuge protects a vast parcel of tidal salt marsh and an extensive network of tidal creeks. These areas are not only essential wildlife habitat, but are critical components for maintaining water quality in Delaware Bay and the Atlantic.

The shells of expired Atlantic Horseshoe Crabs were formerly widespread and common among the naturally occurring flotsam along the high tide line on Delaware Bay. We found just this one during our visit to Bombay Hook. Man has certainly decimated populations of this ancient crustacean during recent decades.

Boardwalk Trail — As the tide goes out, it’s a good time for a quick walk into the salt marsh on the boardwalk trail opposite Raymond Pool.

Among the Saltmarsh Cordgrass along the trail and on the banks of the tidal creek there, a visitor will find thousands and thousands of Atlantic Marsh Fiddler Crabs (Minuca pugnax).

A male Atlantic Marsh Fiddler Crab peers from its den.

A juvenile Clapper Rail (Rallus crepitans crepitans) emerges from the cover of the cordgrass along a tidal creek to search for a meal.

Glossy Ibis leave their high-tide hiding place in Shearness Pool to head out into the tidal marshes for the afternoon.

Great Black-backed Gulls, Herring Gulls, and possibly other species feed on the mudflats exposed by low tide. — Great Black-backed Gulls, Herring Gulls, and possibly other species feed on the mudflats exposed by low tide in the marshes opposite Shearness Pool.

Ospey — An Osprey patrols the vast tidal areas opposite Shearness Pool.

No visit to Bombay Hook is complete without at least a quick loop through the upland habitats at the far end of the tour route.

Indigo Buntings nest in areas of successional growth and yes, that is a Spotted Lanternfly on the grape vine at the far right side of the image.

Trumpet Creeper and Poison Ivy — These two native vines are widespread at Bombay Hook and are an excellent source of food for birds. The orange flowers of the Trumpet Vine are a hummingbird favorite and the Poison Ivy provides berries for numerous species of wintering birds.

Pileated Woodpecker in Sweet Gum — The Pileated Woodpecker is one of the numerous birds that supplements its diet with Poison Ivy berries. The tree this individual is visiting is an American Sweetgum (Liquidambar styraciflua), a species native to the Atlantic Coastal Plain in Delaware. The seed balls are a favorite winter food of goldfinches and siskins.

Red-bellied Slider and Painted Turtle — Finis Pool has no frontage on the tidal marsh but is still worth a visit. It lies along a spur road on the tour route and is located within a deciduous coastal plain forest. Check the waters there for basking turtles like this giant Northern Red-bellied Cooter (Pseudemys rubiventris) and much smaller Painted Turtle.

The White-tailed Deity is common along the road to Finis Pool.

Fowler's Toad — Fowler’s Toads (Anaxyrus fowleri) breed in the vernal ponds found in the vicinity of Finis Pool and elsewhere throughout the refuge.

Turk's Cap Lily — The National Wildlife Refuge System not only protects animal species, it sustains rare and unusual plants as well. This beauty is a Turk’s Cap Lily (Lilium superbum), a native wildflower of wet woods and swamps.

We hope you’ve been convinced to visit Bombay Hook National Wildlife Refuge sometime soon. And we hope too that you’ll help fund additional conservation acquisitions and improvements by visiting your local post office and buying a Federal Duck Stamp.

June 5, 2023June 8, 2023

The Value of Water

Are you worried about your well running dry this summer? Are you wondering if your public water supply is going to implement use restrictions in coming months? If we do suddenly enter a wet spell again, are you concerned about losing valuable rainfall to flooding? A sensible person should be curious about these issues, but here in the Lower Susquehanna River Watershed, we tend to take for granted the water we use on a daily basis.

This Wednesday, June 7, you can learn more about the numerous measures we can take, both individually and as a community, to recharge our aquifers while at the same time improving water quality and wildlife habitat in and around our streams and rivers. From 5:30 to 8:00 P.M., the Chiques Creek Watershed Alliance will be hosting its annual Watershed Expo at the Manheim Farm Show grounds adjacent to the Manheim Central High School in Lancaster County. According to the organization’s web page, more than twenty organizations will be there with displays featuring conservation, aquatic wildlife, stream restoration, Honey Bees, and much more. There will be games and custom-made fish-print t-shirts for the youngsters, plus music to relax by for those a little older. Look for rain barrel painting and a rain barrel giveaway. And you’ll like this—admission and ice cream are free. Vendors including food trucks will be onsite preparing fare for sale.

And there’s much more.

To help recharge groundwater supplies, you can learn how to infiltrate stormwater from your downspouts, parking area, or driveway…

Urban Runoff — Does your local stream flood every time there’s a downpour, then sometimes dry up during the heat of summer? Has this problem gotten worse over the years? If so, you may be in big trouble during a drought. Loss of base flow in a stream or river is a sure sign of depleted groundwater levels in at least a portion of its drainage basin. Landowners, both public and private, in such a watershed need to start infiltrating stormwater into the ground instead of allowing it to become surface runoff.

Rain Garden Model — You can direct the stormwater from your downspout, parking area, or driveway into a rain garden to help recharge the aquifer that supplies your private or public well and nearby natural springs. Displays including this model provided by Rapho Township show you how.

…there will be a tour of a comprehensive stream and floodplain rehabilitation project in Manheim Memorial Park adjacent to the fair grounds…

Legacy Sediments — Have you seen banks like these on your local stream? On waterways throughout the Lower Susquehanna River Watershed, mill dams have trapped accumulations of sediments that eroded from farm fields prior to the implementation of soil conservation practices. These legacy sediments channelize creeks and disconnect them from their now buried floodplains. During storms, water that would have been absorbed by the floodplain is now displaced into areas of higher ground not historically inundated by a similar event.

Adjacent to the Manheim Farm Show grounds, the Chiques Creek Stream Restoration Project in Manheim Memorial Park has reconnected the waterway to its historic floodplain by removing a dam and the legacy sediments that accumulated behind it.

Legacy Sediments Removed — Chiques Creek in Manheim following removal of hundreds of truck loads of legacy sediments. High water can again be absorbed by the wetlands and riparian forest of the floodplain surrounding this segment of stream. There are no incised banks creating an unnatural channel or crumbling away to pollute downstream waters with nutrients and sediment. Projects similar to this are critical to improving water quality in both the Susquehanna River and Chesapeake Bay. Closer to home, they can help municipalities meet their stormwater management (MS4) requirements.

Bank-full Bench — Mark Metzler of Rettew Associates guides a tour of the Chiques Creek rehabilitation. Here, cross vanes, stone structures that provide grade control along the stream’s course, were installed to gently steer the center of the channel away from existing structures. Cross vanes manipulate the velocity of the creek’s flow across its breadth to dissipate potentially erosive energy and more precisely direct the deposition of gravel and sediment.

…and a highlight of the evening will be using an electrofishing apparatus to collect a sample of the fish now populating the rehabilitated segment of stream…

…so don’t miss it. We can hardly wait to see you there!

The 2023 Watershed Expo is part of Lancaster Conservancy Water Week.

March 25, 2023April 17, 2023

Underwater View of Life in a Vernal Pool

It may look like just a puddle in the woods, but this is a very specialized wetland habitat, a habitat that is quickly disappearing from the Lower Susquehanna River Watershed. It’s a vernal pool—also known as a vernal pond or an ephemeral (lasting a short time) pool or pond.

Viable vernal pools have several traits in common…

- - They contain water in the spring (hence the name vernal).
  - They have no permanent inflow or outflow of water.
  - They typically dry up during part of the year—usually in late summer.
  - They are fish-free.
  - They provide breeding habitat for certain indicator species of forest-dwelling amphibians and other animals.
  - They are surrounded by forest habitat that supports the amphibians and other vernal pool species during the terrestrial portion of their life cycle.

To have a closer look at what is presently living in this “black leaf” vernal pool, we’re calling on the crew of the S. S. Haldeman to go down under and investigate.

Along the surface of the pool we’re seeing clusters of amphibian eggs, a sign that this pond has been visited by breeding adult frogs and/or salamanders during recent weeks.

Amphibian eggs and the white tail filaments of an invertebrate of interest, Springtime Fairy Shrimp (Eubranchipus vernalis), an endemic of vernal ponds.

Let’s take it down for a better look. Dive, all dive!

Algae provides food for the shrimp and other inhabitants of the pool. Leaf litter furnishes hiding places for the pool’s many inhabitants.

These loose clusters of eggs appears to be those of Wood Frogs, a vernal pool indicator species.

Clusters of Wood Frog eggs, the embryos within those in the center of the image less developed than those to the left.

More Wood Frog eggs. Hatching can take anywhere from two weeks to two months, depending on temperature.

Wood Frog eggs with developing larvae (tadpoles) plainly visible. The green color of the eggs is created by a symbiotic algae, Oophila amblystomatis, a species unique to vernal pools. The algae utilizes the waste produced by the developing embryos to fuel its growth and in return releases oxygen into the water during photosynthesis. Upon hatching, the tadpoles rely upon the algae as one of their principle food sources.

A zoomed-in view showing development of the larvae and what appears to be a tiny invertebrate clinging on the white egg in the upper right. White eggs don’t hatch and may be infected by a fungus.

Wood Frog eggs and Springtime Fairy Shrimp.

Springtime Fairy Shrimp swim upside-down. Note the small, bluish clusters of eggs attached to the abdomens of these females. Springtime Fairy Shrimp live their entire lives in the vernal pool. After being deposited in the debris at the bottom of the pool, the eggs will dry out during the summer, then freeze and re-hydrate before hatching during the late winter.

A damselfly larva consuming fairy shrimp. (Visible in the margin between the uppermost lobes of the dark-colored oak leaf to the right.)

Getting in close we see A) the damselfly larva eating a Springtime Fairy Shrimp and B) one of several discarded exoskeletons of consumed shrimp near this predator.

A fishfly larva (Chauliodinae). Mosquito numbers are kept in check by the abundance of predators in these pools.

Springtime Fairy Shrimp and a Marbled Salamander (Ambystoma opacum) larva. The presence of these species confirms this small body of water is a fully-functioning vernal pool.

Springtime Fairy Shrimp and two more larval Marbled Salamanders. The salamanders’ enlarged gills are necessary to extract sufficient oxygen from the still waters of the pool.

The Marbled Salamander is one of three species of mole salamanders found in the Lower Susquehanna River Watershed. All breed in vernal pools and live their air-breathing adult lives under the leaves of the forest in subterranean tunnels where they feed on worms and other invertebrates. Photos of an adult Marbled Salamander and the other two species, Spotted Salamander (Ambystoma maculatum) and Jefferson Salamander (Ambystoma jeffersonianum), can be found by clicking the “Amphibians” tab at the top of this page.

Marbled Salamanders lay their eggs during the fall. If the bed of the pool is dry at breeding time, the adult female will remain to guard the eggs until rain floods the pool. The eggs hatch upon inundation, sometimes during the winter.

Marbled Salamanders, like all amphibians that develop in vernal pools, must complete transformation into their air-breathing terrestrial life stage before the pool dries up in the summer heat.

A larval Marbled Salamander explores the bottom of the pool.

A larval Marbled Salamander, Wood Frog eggs, and Springtime Fairy Shrimp, it’s an abundance of life in what at first glance may appear to be just a mud puddle.

We hope you enjoyed this quick look at life in a vernal pool. While the crew of the S. S. Haldeman decontaminates the vessel (we always scrub and disinfect the ship before moving between bodies of water) and prepares for its next voyage, you can learn more about vernal pools and the forest ecosystems of which they are such a vital component. Be sure to check out…

- - The Pennsylvania Natural Heritage Program page

If you are a landowner or a land manager, you can find materials specifically providing guidance for protecting, restoring, and re-establishing vernal pool habitats at…

- - The Pennsylvania Natural Heritage Program’s Vernal Pool Resources page

**Wasted Effort-**A pair of Wood Frogs mating in a dried-up vernal pool.

March 3, 2023August 14, 2023

Plantings for Wet Lowlands

This linear grove of mature trees, many of them nearly one hundred years old, is a planting of native White Oaks (Quercus alba) and Swamp White Oaks (Quercus bicolor).

Imagine the benefit of trees like this along that section of stream you’re mowing or grazing right now. The Swamp White Oak in particular thrives in wet soils and is available now for just a couple of bucks per tree from several of the lower Susquehanna’s County Conservation District Tree Sales. These and other trees and shrubs planted along creeks and rivers to create a riparian buffer help reduce sediment and nutrient pollution. In addition, these vegetated borders protect against soil erosion, they provide shade to otherwise sun-scorched waters, and they provide essential wildlife habitat. What’s not to love?

The following native species make great companions for Swamp White Oaks in a lowland setting and are available at bargain prices from one or more of the County Conservation District Tree Sales now underway…

The Red Maple is an ideal tree for a stream buffer project. They do so well that you should limit them to 10% or less of the plants in your project so that they don’t overwhelm slower-growing species.

The River Birch (Betula nigra) is a multi-trunked tree of lowlands. Large specimens with arching trunks help shade waterways and provide a source of falling insects for surface-feeding fish. Its peeling bark is a distinctive feature.

American Robins feeding on Common Winterberry. — An American Robin feeding on Common Winterberry.

Common Spicebush is a shrub of moist lowland soils. It is the host plant for the Spicebush Swallowtail butterfly and produces small red berries for birds and other wildlife. Plant it widely among taller trees to provide native vegetation in the understory of your forest.

Common Spicebush foliage and berries. — Common Spicebush foliage and berries in the shade beneath a canopy of tall trees.

The Common Pawpaw a small shade-loving tree of the forest understory.

The Buttonbush is a shrub of wet soils. It produces a round flower cluster, followed by this globular seed cluster.

And don’t forget the Eastern Sycamore, the giant of the lowlands. At maturity, the white-and-tan-colored bark on massive specimens makes them a spectacular sight along stream courses and river shores. Birds ranging from owls, eagles, and herons to smaller species including the Yellow-throated Warbler rely upon them for nesting sites.

Yellow-crowned Night Herons Nesting in an Eastern Sycamore — Yellow-crowned Night Herons, an endangered species in Pennsylvania, nesting in an Eastern Sycamore.

So don’t mow, do something positive and plant a buffer!

Act now to order your plants because deadlines are approaching fast. For links to the County Conservation District Tree Sales in the Lower Susquehanna River Watershed, see our February 18th post.

August 25, 2022August 26, 2022

Photo of the Day

Freshwater Bryozoan Colony (Pectinatella magnifica) and an Eastern Amberwing — Those who happen to come upon it might think this football-sized gelatinous blob is a sure sign of pollution. A freshwater bryozoan (Pectinatella magnifica) colony is composed of a single microscopic founder and its many clones. Despite its bizarre appearance, the “moss animal” is an indicator of good water quality. Pectinatella magnifica is found in clear lentic (still) waters of streams, lakes, and ponds where each individual in the colony feeds by extending a disk of sticky tentacles, called a lophophore, from within its protective sheath to capture single-celled algae (e.g., diatoms) and other plankton. From now through autumn, these bryozoans are reproducing by means of cell-filled statoblasts, durable little seedlike pods which can survive the harsh conditions of both winter and drought and sometimes be transported by animals, wind, or water currents to new areas. Spring weather and/or rehydration of a dried-up lentic pool stimulates a statoblast to open, the cells contained therein then develop into a zooid that attempts to start a new colony by cloning itself.

August 10, 2022August 13, 2022

Shakedown Cruise of the S. S. Haldeman

First there was the Nautilus. Then there was the Seaview. And who can forget the Yellow Submarine? Well, now there’s the S. S. Haldeman, and today we celebrated her shakedown cruise and maiden voyage. The Haldeman is powered by spent fuel that first saw light of day near Conewago Falls at a dismantled site that presently amounts to nothing more than an electrical substation. Though antique in appearance, the vessel discharges few emissions, provided there aren’t any burps or hiccups while underway. So, climb aboard as we take a cruise up the Susquehanna at periscope depth to have a quick look around!

Brunner Island as seen from the east channel.

Close-in approach to emergent Water Willow growing on an alluvial Island.

The approach to York Haven Dam and Conewago Falls from the west channel.

A pair of Powdered Dancers on a midriver log.

Watertight and working fine. Let’s flood the tanks and have a peek at the benthos. Dive, all dive!

American Eelgrass/Tapegrass — American Eelgrass, also known as Tapegrass, looks to be growing well in the channels. Historically, vast mats of this plant were the primary food source for the thousands of Canvasback ducks that once visited the lower Susquehanna each autumn.

As is Water Stargrass (Heteranthera dubia). When mature, both of these native plants provide excellent cover for young fish. Note the abundance of shells from deceased Asiatic Clams (Corbicula fluminea) covering the substrate.

Mayfly nymph — A three-tailed mayfly (Ephemeroptera) nymph and a several exoskeletons cling to the downstream side of a rock.

Comb-lipped Casemaker Caddisfly larva and case. — This hollowed-out stick may be a portable protective shelter belonging to a Comb-lipped Casemaker Caddisfly larva (Calamoceratidae). The larva itself appears to be extending from the end of the “case” in the upper right of the image. Heteroplectron americanum, a species known for such behavior, is a possibility.

In the Susquehanna and its tributaries, the Rusty Crayfish (Faxonius rusticus) is an introduced invasive species. It has little difficulty displacing native species due to its size and aggressiveness.

Freshwater Snails Susquehanna: Virginian River Horn Snail — Summers with conditions that promote eelgrass and stargrass growth tend to be big years for Virginian River Horn Snails (Elimia virginica). 2022 appears to be one of those years. They’re abundant and they’re everywhere on the rocks and gravel substrate in midriver. Feeding almost incessantly on algae and detritus, these snails are an essential component of the riverine ecosystem, breaking down organic matter for final decomposition by bacteria and fungi.

Susquehanna Snails: Virginian River Horn Snails and Lesser Mystery Snails — Virginian River Horn Snails with Lesser Mystery Snails (Campeloma decisum), another native species commonly encountered at Conewago Falls and in surrounding waters.

Freshwater Snails Susquehanna: River Snail and Virginian River Horn Snail — A River Snail (Leptoxis carinata), also known as a Crested Mudalia, hitching a ride on a Virginian River Horn Snail. The two species are frequently found together.

Mollusks of the Susquehanna: Yellow Lampmussel and River Snail — A River Snail cleaning the shell of a native freshwater Unionidae mussel, Lampsilis cariosa, commonly called the Yellow Lampmussel or Carried Lampmussel. Because of their general decline in abundance and range, all Unionidae mussels are protected in Pennsylvania.

Fishes of the Susquehanna: Banded Darter — The Banded Darter (Etheostoma zonale) is a member of the perch family (Percidae).

Fishes of the Susquehanna: Smallmouth Bass — A Smallmouth Bass in strong current.

Fishes of the Susquehanna: Spotfin or Satinfin Shiners — Along the edge of an alluvial island at midriver, Cyprinella (Spotfin or Satinfin) Shiners gather in the cover of an emergent stand of Water Willow. The closely related Spotfin Shiner (Cyprinella spiloptera) and Satinfin Shiner (Cyprinella analostanus) are nearly impossible to differentiate in the field.

Fishes of the Susquehanna: Spotfin or Satinfin Shiner — A breeding condition male Cyprinella (Spotfin or Satinfin) Shiner.

Fishes of the Susquehanna; Juvenile Channel Catfish — A juvenile Channel Catfish.

We’re finding that a sonar “pinger” isn’t very useful while running in shallow water. Instead, we should consider bringing along a set of Pings—for the more than a dozen golf balls seen on the river bottom. It appears they’ve been here for a while, having rolled in from the links upstream during the floods. Interestingly, several aquatic species were making use of them.

A golf ball used as an anchor point for silk cases woven by Net-spinning Caddisfly (Hydropsychidae) larvae to snare food from the water column.

Freshwater Snails (Gastropods) of the Lower Susquehanna River Watershed: Creeping Ancylid (Ferrissia species) — A Creeping Ancylid (Ferrissia species), a tiny gastropod also known as a Coolie Hat Snail, River Limpet, or Brook Freshwater Limpet, inhabits the dimple on a “Top Flight”.

We now know why your golf balls always end up in the drink, it’s where they go to have their young.

Well, it looks like the skipper’s tired and grumpy, so that’s all for now. Until next time, bon voyage!

July 29, 2022August 17, 2022

Monarch an Endangered Species: What You Can Do Right Now

This month, the International Union for Conservation of Nature (I.U.C.N.) added the Migratory Monarch Butterfly (Danaus plexippus plexippus) to its “Red List of Threatened Species”, classifying it as endangered. Perhaps there is no better time than the present to have a look at the virtues of replacing areas of mowed and manicured grass with a wildflower garden or meadow that provides essential breeding and feeding habitat for Monarchs and hundreds of other species of animals.

Monarch on Common Milkweed Flower Cluster — A recently arrived Monarch visits a cluster of fragrant Common Milkweed flowers in the garden at the susquehannawildlife.net headquarters. Milkweeds included among a wide variety of plants in a garden or meadow habitat can help local populations of Monarchs increase their numbers before the autumn flights to wintering grounds commence in the fall. Female Monarchs lay their eggs on milkweed leaves, then, after hatching, the larvae (caterpillars) feed on them before pupating.

If you’re not quite sure about finally breaking the ties that bind you to the cult of lawn manicuring, then compare the attributes of a parcel maintained as mowed grass with those of a space planted as a wildflower garden or meadow. In our example we’ve mixed native warm season grasses with the wildflowers and thrown in a couple of Eastern Red Cedars to create a more authentic early successional habitat.

Comparison of Mowed Grass to Wildflower Meadow — * Particularly when native warm-season grasses are included (root depth 6′-8′)

Still not ready to take the leap. Think about this: once established, the wildflower planting can be maintained without the use of herbicides or insecticides. There’ll be no pesticide residues leaching into the soil or running off during downpours. Yes friends, it doesn’t matter whether you’re using a private well or a community system, a wildflower meadow is an asset to your water supply. Not only is it free of man-made chemicals, but it also provides stormwater retention to recharge the aquifer by holding precipitation on site and guiding it into the ground. Mowed grass on the other hand, particularly when situated on steep slopes or when the ground is frozen or dry, does little to stop or slow the sheet runoff that floods and pollutes streams during heavy rains.

What if I told you that for less than fifty bucks, you could start a wildflower garden covering 1,000 square feet of space? That’s a nice plot 25′ x 40′ or a strip 10′ wide and 100′ long along a driveway, field margin, roadside, property line, swale, or stream. All you need to do is cast seed evenly across bare soil in a sunny location and you’ll soon have a spectacular wildflower garden. Here at the susquehannawildllife.net headquarters we don’t have that much space, so we just cast the seed along the margins of the driveway and around established trees and shrubs. Look what we get for pennies a plant…

Here’s a closer look…

Lance-leaved Coreopsis (Coreopsis lanceolata), a perennial.

Black-eyed Susan, a biennial or short-lived perennial.

Black-eyed Susan "Gloriosa Daisy" — “Gloriosa Daisy”, a variety of Black-eyed Susan, a biennial or short-lived perennial.

A short variety of Common Sunflower, an annual and a source of free bird seed.

All this and best of all, we never need to mow.

Around the garden, we’ve used a northeast wildflower mix from American Meadows. It’s a blend of annuals and perennials that’s easy to grow. On their website, you’ll find seeds for individual species as well as mixes and instructions for planting and maintaining your wildflower garden. They even have a mix specifically formulated for hummingbirds and butterflies.

Annuals in bloom — When planted in spring and early summer, annuals included in a wildflower mix will provide vibrant color during the first year. Many varieties will self-seed to supplement the display provided by biennials and perennials in subsequent years.

Wildflower Seed Mix — A northeast wildflower mix from American Meadows. There are no fillers. One pound of pure live seed easily plants 1,000 square feet.

Nothing does more to promote the spread and abundance of non-native plants, including invasive species, than repetitive mowing. One of the big advantages of planting a wildflower garden or meadow is the opportunity to promote the growth of a community of diverse native plants on your property. A single mowing is done only during the dormant season to reseed annuals and to maintain the meadow in an early successional stage—preventing reversion to forest.

For wildflower mixes containing native species, including ecotypes from locations in and near the Lower Susquehanna River Watershed, nobody beats Ernst Conservation Seeds of Meadville, Pennsylvania. Their selection of grass and wildflower seed mixes could keep you planting new projects for a lifetime. They craft blends for specific regions, states, physiographic provinces, habitats, soils, and uses. Check out these examples of some of the scores of mixes offered at Ernst Conservation Seeds…

- - Pipeline Mixes
  - Pasture, Grazing, and Hay Mixes
  - Cover Crops
  - Pondside Mixes
  - Warm-season Grass Mixes
  - Retention Basin Mixes
  - Wildlife Mixes
  - Pollinator Mixes
  - Wetland Mixes
  - Floodplain and Riparian Buffer Mixes
  - Rain Garden Mixes
  - Steep Slope Mixes
  - Solar Farm Mixes
  - Strip Mine Reclamation Mixes

We’ve used their “Showy Northeast Native Wildflower and Grass Mix” on streambank renewal projects with great success. For Monarchs, we really recommend the “Butterfly and Hummingbird Garden Mix”. It includes many of the species pictured above plus “Fort Indiantown Gap” Little Bluestem, a warm-season grass native to Lebanon County, Pennsylvania, and milkweeds (Asclepias), which are not included in their northeast native wildflower blends. More than a dozen of the flowers and grasses currently included in this mix are derived from Pennsylvania ecotypes, so you can expect them to thrive in the Lower Susquehanna River Watershed.

Swamp Milkweed, a perennial species, is included in the Ernst Seed “Butterfly and Hummingbird Garden Mix”. It is a favorite of female Monarchs seeking a location to deposit eggs.

Monarch Caterpillar feeding on Swamp Milkweed — A Monarch larva (caterpillar) feeding on Swamp Milkweed.

Butterfly Weed (Asclepias tuberosa) is included in the Ernst Seed “Butterfly and Hummingbird Garden Mix”. This perennial is also known as Butterfly Milkweed.

Tiger Swallowtails visiting Butterfly Weed — Eastern Tiger Swallowtails are among the dozens of species of pollinators that will visit Butterfly Weed.

In addition to the milkweeds, you’ll find these attractive plants included in Ernst Conservation Seed’s “Butterfly and Hummingbird Garden Mix”, as well as in some of their other blends.

The perennial Wild Bergamot, also known as Bee Balm, is an excellent pollinator plant, and the tubular flowers are a favorite of hummingbirds.

Oxeye is adorned with showy clusters of sunflower-like blooms in mid-summer. It is a perennial plant.

Plains Coreopsis (Coreopsis tinctoria), also known as Plains Tickseed, is a versatile annual that can survive occasional flooding as well as drought.

Gray-headed Coneflower (Ratibida pinnata), a tall perennial, is spectacular during its long flowering season.

Monarch on goldenrod. — Goldenrods are a favorite nectar plant for migrating Monarchs in autumn. They seldom need to be sown into a wildflower garden; the seeds of local species usually arrive on the wind. They are included in the “Butterfly and Hummingbird Garden Mix” from Ernst Conservation Seeds in low dose, just in case the wind doesn’t bring anything your way.

Is something missing from your seed mix? You can purchase individual species from the selections available at American Meadows and Ernst Conservation Seeds. Partridge Pea is a good native annual to add. It is a host plant for the Cloudless Sulphur butterfly and hummingbirds will often visit the flowers. It does really well in sandy soils.

Indiangrass in flower. — Indiangrass is a warm-season species that makes a great addition to any wildflower meadow mix. Its deep roots make it resistant to drought and ideal for preventing erosion.

Why not give the Monarchs and other wildlife living around you a little help? Plant a wildflower garden or meadow. It’s so easy, a child can do it.

Planting a riparian buffer with wildflowers and warm-season grasses — Volunteers sow a riparian buffer on a recontoured stream bank using wildflower and warm-season grass seed blended uniformly with sand. By casting the sand/seed mixture evenly over the planting site, participants can visually assure that seed has been distributed according to the space calculations.

Riparian Buffer of wildflowers — The same seeded site less than four months later.

Monarch Pupa — A Monarch pupa from which the adult butterfly will emerge.

April 14, 2022September 12, 2023

Emergence of the Turtles

Along the lower Susquehanna, an unseasonably mild day in early spring can provide an observer with the opportunity to witness an annual spectacle seldom seen by the average visitor to the river—concentrations of dozens, sometimes hundreds, of turtles as they emerge from their winter slumber to bathe in the year’s first surge of warm air and sunshine.

Reptiles of the Lower Susquehanna River Watershed: Snapping Turtle — Snapping Turtles (Chelydra serpentina) spend the winter buried in mud along the river shoreline and in nearby Alluvial Terrace Wetlands. We photographed this one just as it was digging its way out.

Reptiles of the Lower Susquehanna River Watershed: Painted Turtles — Freshly emerged Painted Turtles clamber onto a log to bask in the cloud-filtered sun.

Reptiles of the Lower Susquehanna River Watershed: Painted Turtle atop a Snapping Turtle — A Painted Turtle looking for a place to get out of the chilly water soon discovered the obvious solution.

It’s catching on, more Painted Turtles atop a Snapping Turtle in an Alluvial Terrace Wetland.

Reptiles of the Lower Susquehanna River Watershed: Red-eared Slider and Common Map Turtle — The Common Map Turtle (right) is the turtle most frequently observed basking on rocks and logs along the main stem of the Susquehanna. To the left is a Red-eared Slider (Trachemys scripta elegans), an increasingly numerous invasive species. The first Red-eared Sliders arrived in the river as, you guessed it, unwanted pets. Editor’s Note: Special thanks to the local North American Beaver (Castor canadensis) for trimming the trees and providing a clear shot for this photograph!

Reptiles of the Lower Susquehanna River Watershed: Red-eared Slider and Painted Turtles — And now, a quick quiz. Name the things that don’t belong in this picture? Here’s a hint: a non-native Red-eared Slider (left) joins indigenous Painted Turtles atop a discarded tire in an Alluvial Terrace Wetland in Dauphin County, Pennsylvania.

April 12, 2022

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Great Blue Heron — A Great Blue Heron in breeding plumage searches for prey in an Alluvial Terrace Wetland.

April 11, 2022April 11, 2022

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: American Robin — An American Robin searches wet leaves for earthworms and other invertebrates along the edge of an Alluvial Terrace Wetland near the Susquehanna.

March 23, 2021August 15, 2022

Forest vs. Woodlot

Let’s take a quiet stroll through the forest to have a look around. The spring awakening is underway and it’s a marvelous thing to behold. You may think it a bit odd, but during this walk we’re not going to spend all of our time gazing up into the trees. Instead, we’re going to investigate the happenings at ground level—life on the forest floor.

Rotting logs and leaf litter create the moisture retaining detritus in which mesic forest plants grow and thrive. Note the presence of mosses and a vernal pool in this damp section of forest.

The earliest green leaves in the forest are often those of the Skunk Cabbage (Simplocarpus foetidus). This member of the arum family gets a head start by growing in the warm waters of a spring seep or in a stream-fed wetland. Like many native wildflowers of the forest, Skunk Cabbage takes advantage of early-springtime sun to flower and grow prior to the time in late April when deciduous trees grow foliage and cast shade beneath their canopy.

Among the bark of dead and downed trees, the Mourning Cloak butterfly (Nymphalis antiopa) hibernates for the winter. It emerges to alight on sun-drenched surfaces in late winter and early spring.

Another hibernating forest butterfly that emerges on sunny early-spring days is the Eastern Comma (Polygonia comma), also known as the Hop Merchant.

In a small forest brook, a water strider (Gerridae) chases its shadow using the surface tension of the water to provide buoyancy. Forests are essential for the protection of headwaters areas where our streams get their start.

Often flooded only in the springtime, fish-free pools of water known as vernal ponds are essential breeding habitat for many forest-dwelling amphibians. Unfortunately, these ephemeral wetland sites often fall prey to collecting, dumping, filling, and vandalism by motorized and non-motorized off-roaders, sometimes resulting in the elimination of the populations of frogs, toads, and salamanders that use them.

Wood Frogs (Lithobates sylvaticus) emerge from hiding places among downed timber and leaf litter to journey to a nearby vernal pond where they begin calling still more Wood Frogs to the breeding site.

Wood Frog eggs must hatch and tadpoles must transform into terrestrial frogs before the pond dries up in the summertime. It’s a risky means of reproduction, but it effectively evades the enormous appetites of fish.

When the egg laying is complete, adult Wood Frogs return to the forest and are seldom seen during the rest of the year.

In early spring, Painted Turtles emerge from hideouts in larger forest pools, particularly those in wooded swamps, to bask in sunny locations.

Dead standing trees, often called snags, are essential habitats for many species of forest wildlife. There is an entire biological process, a micro-ecosystem, involved in the decay of a dead tree. It includes fungi, bacteria, and various invertebrate animals that reduce wood into the detritus that nourishes and hydrates new forest growth.

Birds like this Red-headed Woodpecker feed on insects found in large snags and nest almost exclusively in them. Many species of wildlife rely on dead trees, both standing and fallen, during all or part of their lives.

There certainly is more to a forest than the living trees. If you’re hiking through a grove of timber getting snared in a maze of prickly Multiflora Rose (Rosa multiflora) and seeing little else but maybe a wild ungulate or two, then you’re in a has-been forest. Logging, firewood collection, fragmentation, and other man-made disturbances inside and near forests take a collective toll on their composition, eventually turning them to mere woodlots. Go enjoy the forests of the lower Susquehanna valley while you still can. And remember to do it gently; we’re losing quality as well as quantity right now—so tread softly.

The White-tailed Deity in a woodlot infested by invasive tangles of Multiflora Rose.

April 5, 2020April 6, 2020

Get Away From It All

For those of you who dare to shed that filthy contaminated rag you’ve been told to breathe through so that you might instead get out and enjoy some clean air in a cherished place of solitude, here’s what’s around—go have a look.

Northern Flickers have arrived. Look for them anywhere there are mature trees. Despite the fact that flickers are woodpeckers, they often feed on the ground. You’ll notice the white rump and yellow wing linings when they fly away.

The tiny Chipping Sparrow frequently nests in small trees in suburban gardens. Lay off the lawn treatments to assure their success.

Field Sparrows (Spizella fusilla) are a breeding species in abandoned fields where successional growth is underway.

White-throated Sparrows spend the winter in the lower Susquehanna valley. Their numbers are increasing now as waves of migrants pass through on their way north.

Northbound flocks of Rusty Blackbirds (Euphagus carolinus) are currently found feeding in forest swamps along the Susquehanna. Their noisy calls sound like a chorus of squeaking hinges.

Migratory Red-shouldered Hawks are also making feeding stops at area wetlands.

The Palm Warbler (Setophaga palmarum) is easily identified by its tail pumping behavior. Look for it in shrubs along the river shoreline or near lakes and streams. Palm Warblers are among the earliest of the warblers to move through in the spring.

The springtime show on the water continues…

Common Loons will continue migrating through the area during the upcoming month.

Buffleheads are still transiting the watershed.

Horned Grebes are occurring on the river and on local lakes.

Seeing these one-year-old male Hooded Mergansers, the bachelors, wandering around without any adult males or females is a good sign. The adults should have moved on to the breeding grounds and local pairs should be well into a nesting cycle by now. Hatching could occur any day.

Like Hooded Mergansers, Wood Ducks are cavity nesters, but their egg laying, incubation, and hatching often occurs a month or more later than that of the hoodies. Judging by the attentiveness of the drake, this pair of woodies is probably in the egg-laying stage of its breeding cycle right now.

Redheads (Aythya americana) are stopping for a rest on their way north.

In spring, Double-crested Cormorants proceed up the river in goose-like flocks with adult birds like these leading the way.

Hey, what are those showy flowers?

That’s Lesser Celandine (Ficaria verna). It’s often called Fig Buttercup. In early April it blankets stream banks throughout the lower Susquehanna region. If you don’t remember seeing it growing like that when you were younger, there’s a reason. Lesser Celandine is an escape from cultivation that has become invasive. While the appearance is tolerable; it’s the palatability that ruins everything. It’s poisonous if eaten by people or livestock.

The Eastern Spring Beauty (Claytonia virginica) is a dainty native wildflower of riparian forests and other woodlands throughout the lower Susquehanna valley.

The Trout Lily (Erythronium americanum) is beginning to bloom now. It’s a native of the region’s damp forests.

Virginia Bluebells (Mertensia virginica) is not native to the Susquehanna watershed, but neither is it considered invasive. It creates colorful patches in riparian forests.

Dutchman’s Breeches (Dicentra cucullaria) is a strikingly beautiful native wildflower that grows on undisturbed forested slopes throughout the Susquehanna valley.

Wasn’t that refreshing? Now go take a walk.

August 18, 2018August 15, 2022

They Call Me the Wanderer

It’s been an atypical summer. The lower Susquehanna River valley has been in a cycle of heavy rains for over a month and stream flooding has been a recurring event. At Conewago Falls, the Pothole Rocks have been inundated for weeks. The location used as a lookout for the Autumn Migration Count last fall is at the moment submerged in ten feet of roaring water. Any attempt to tally the migrants which are passing thru in 2018 will thus be delayed indefinitely. Of greater import, the flooding at Conewago Falls is impacting many of the animals and plants there at a critical time in their annual life cycle. Having been displaced from its usual breeding sites on the river, one insect species in particular seems to be omnipresent in upland areas right now, and few people have ever heard of it.

So, you take a cruise in the motorcar to your favorite store and arrive at the sprawling parking lot. Not wishing to have your doors dented or paint chipped because you settled for a space tightly packed among other shopper’s conveyances, you park out there in the “boondocks”. You know the place, the lightly-used portion of the lot where sometimes brush grows from cracks in the asphalt and you must be on alert for impatient consumers who throttle-up to high speeds and dash diagonally across the carefully painted grids on the pavement to reach their favorite parking destination in the front row. Coming to a stop, you take the car out of gear, set the brake, disengage the safety belt, and gather your shopping list. You grasp the door handle and, not wanting to be flattened by one of the aforementioned motorists, you have a look around before exiting.

It was then that you saw the thing, hovering above your shiny bright hood. For a brief moment, it seemed to be peering right through the windshield at you with big reddish-brown eyes. In just a second or two, it turned its whole bronze body ninety degrees to the left and darted away on its cellophane wings. Maybe you didn’t really get a good look at it. It was so fast. But it certainly was odd. Oh well, time to walk inside a grab a few provisions. Away you go.

Upon completion of your shopping, you’re taking the long stroll back to your car and you notice more of these peculiar creatures. Two are coupled together and are hovering above someone’s automobile hood, then they drop down, and the lower of the two taps its abdomen on the paint. You ask yourself, “What are these bizarre things?”

Meet the Wandering Glider (Pantala flavescens), also known as the Globe Wanderer or Globe Skimmer, a wide-ranging dragonfly known to occur on every continent with the exception of Antarctica.

Wandering Gliders sometimes arrive in the lower Susquehanna River valley in large numbers after catching a ride on sustained winds from southerly directions and will often fly and migrate in storm systems. Conditions for such movements have been optimal in our region since mid-July. These dragonflies will often hover above motor vehicle hoods and, after mating, females will deposit eggs upon them, apparently mistaking their glossy surface for small pools of water.

Wandering Gliders travel the globe, and as such are accomplished fliers. Adults spend most of the day on the wing, feeding upon a variety of flying insects. Days ago, I watched several intercepting a swarm of flying ants. As fast as ants left the ground they were grabbed and devoured by the gliders. Wandering Gliders are adept at taking day-flying mosquitos, often zipping stealthily past a person’s head or shoulders to grab one of the little pests—the would-be skeeter victim usually unaware of the whole affair.

Due to their nomadic life history, Wandering Gliders are opportunists when breeding and will lay eggs in most any body of freshwater. Their larvae do not overwinter prior to maturity; adults can be expected in a little more than one to two months. Repetitive flooding in the Lower Susquehanna River Watershed this summer may be reducing the availability of the best local breeding sites for this species—riverine, stream, and floodplain pools of standing water with prey. This may explain why thousands of Wandering Gliders are patrolling parking lots, farmlands, and urban areas this summer. And it’s the likely reason for their use of puddles on asphalt pavement, on rubber roofs, and in fields as places to try to deposit eggs. Unfortunately, they may be as likely to succeed there as they are on your motor vehicle hood.

At this time a year ago, the airspace above the Diabase Pothole Rocks at Conewago Falls was jammed with territorial male Wandering Gliders. Each male hovered at various locations around his breeding territory consisting of pools and water-filled potholes. Intruders would quickly be dispatched from the area, then the male would resume his patrols from a set of repetitively-used hovering positions about six feet above the rocks. Mating and egg-laying continued into late September. The larvae, also called nymphs or naiads, were readily observed in many pools and potholes in early October and the emergence of juveniles was noted in mid-October. The absence of flooding, the mild autumn weather, and the moderation of water temperatures in the pools and potholes courtesy of the sun-drenched diabase boulders helped to extend the 2017 breeding season for Wandering Gliders in Conewago Falls. They aren’t likely to experience the same favor this year, but their great ability to travel and adapt should overcome this momentary misfortune.

A male Wandering Glider aggressively patrols his territory in the Diabase Pothole Rocks Microhabitat at Conewago Falls. August 20, 2017.

A mating pair of Wandering Gliders continue flying non-stop above one of thousands of suitable breeding pools among the Diabase Pothole Rocks at Conewago Falls. September 23, 2017.

A female (bottom)Wandering Glider has deposited eggs in a pool while flying in tandem with a male (top). They’ll do the same thing on your automobile hood! Conewago Falls Diabase Pothole Rocks Microhabitat. September 23, 2017.

Wandering Glider larvae are at the top of the food chain in flooded potholes. As they grew, these dragonfly larvae decimated the mosquito larvae which were abundant there earlier in the summer. October 7, 2017.

A juvenile male Wandering Glider emerges from the pool where it fed and grew as a larva. It remained at water’s edge on the surface of a sun-warmed diabase rock for several hours to dry its wings. It soon flew away to parts unknown, possibly traveling hundreds or thousands of miles. Look carefully at the wings for the beige dash marks on the forward edge near the terminal end. Females lack this marking. Conewago Falls Diabase Pothole Rocks Microhabitat. October 14, 2017.

A Wandering Glider exuviae, the shed exoskeleton of a creature gone, but not forgotten. October 14, 2017.

June 28, 2018April 1, 2021

Shocking Fish Photos!

There are two Conewago Creek systems in the Lower Susquehanna River Watershed. One drains the Gettysburg Basin west of the river, mostly in Adams and York Counties, then flows into the Susquehanna at the base of Conewago Falls. The other drains the Gettysburg Basin east of the river, flowing through Triassic redbeds of the Gettysburg Formation and York Haven Diabase before entering Conewago Falls near the south tip of Three Mile Island. Both Conewago Creeks flow through suburbia, farm, and forest. Both have their capacity to support aquatic life impaired and diminished by nutrient and sediment pollution.

This week, some of the many partners engaged in a long-term collaboration to restore the east shore’s Conewago Creek met to have a look at one of the prime indicators of overall stream habitat health—the fishes. Kristen Kyler of the Lower Susquehanna Initiative organized the effort. Portable backpack-mounted electrofishing units and nets were used by crews to capture, identify, and count the native and non-native fishes at sampling locations which have remained constant since prior to the numerous stream improvement projects which began more than ten years ago. Some of the present-day sample sites were first used following Hurricane Agnes in 1972 by Stambaugh and Denoncourt and pre-date any implementation of sediment and nutrient mitigation practices like cover crops, no-till farming, field terracing, stormwater control, nutrient management, wetland restoration, streambank fencing, renewed forested stream buffers, or modernized wastewater treatment plants. By comparing more recent surveys with this baseline data, it may be possible to discern trends in fish populations resulting not only from conservation practices, but from many other variables which may impact the Conewago Creek Warmwater Stream ecosystem in Dauphin, Lancaster, and Lebanon Counties.

So here they are. Enjoy these shocking fish photos.

Matt Kofroth, Watershed Specialist with the Lancaster County Conservation District, operates the electrofishing wand in Conewago Creek while his team members prepare to net and collect momentarily-stunned fish. Three other electrofishing units operated by staff from the Susquehanna River Basin Commission and aided by teams of netters were in action at other sample locations along the Conewago on this day.

Really big fish, such as this Common Carp (Cyprinus carpio), were identified, counted, and immediately returned to the water downstream of the advancing electrofishing team. Koi of the garden pond are a familiar variety of Common Carp, a native of Asia.

Other fish, such as the Swallowtail Shiner, Redbreast Sunfish (Lepomis auritus), Fallfish, and suckers seen here, were placed in a sorting tank.

Fallfish (Semotilus corporalis) are very active and require plenty of dissolved oxygen in the water to survive. Fallfish, Rainbow Trout (Oncorhynchus mykiss), and Smallmouth Bass (Micropterus dolomieu) were quickly identified and removed from the sorting tank for release back into the stream. Other larger, but less active fish, including suckers, quickly followed.

Small fish like minnows were removed from the sorting tank for a closer look in a hand-held viewing tank. This Fathead Minnow (Pimephales promelas) was identified, added to the tally sheet, and released back into the Conewago. The Fathead Minnow is not native to the Susquehanna drainage. It is the minnow most frequently sold as bait by vendors.

A breeding condition male Bluntnose Minnow (Pimephales notatus).

The Cutlips Minnow (Exoglossum maxillingua) is a resident of clear rocky streams. Of the more than 30 species collected during the day, two native species which are classified as intolerant of persisting stream impairment were found: Cutlips Minnow and Swallowtail Shiner.

This young River Chub (Nocomis micropogon) is losing its side stripe. It will be at least twice as large at adulthood.

The Eastern Blacknose Dace (Rhinichthys atratulus) is found in clear water over pebble and stone substrate..

The Longnose Dace (Rhinichthys cataractae) is another species of pebbly rocky streams.

A juvenile Golden Shiner (Notemigonus crysoleucas). Adults lack the side stripe and grow to the size of a sunfish.

A Swallowtail Shiner (Notropis procne) and a very young White Sucker (Catostomus commersonii) in the upper left of the tank.

A Spotfin Shiner (Cyprinella spiloptera).

A breeding male Spotfin Shiner. Show-off!

The Margined Madtom (Noturus insignis) is a small native catfish of pebbly streams.

The Banded Killifish (Fundulus diaphanus) is adept at feeding upon insects, including mosquitos.

A young Rock Bass (Ambloplites rupestris). This species was introduced to the Susquehanna and its tributaries.

The Greenside Darter (Etheostoma blennioides) is not native to the Susquehanna basin. The species colonized the Conewago Creek (east) from introduced local populations within the last five years.

The Tessellated Darter (Etheostoma olmstedi) is a native inhabitant of the Susquehanna and its tributaries.

The stars of the day were the American Eels (Anguilla rostrata).

After collection, each eel was measured and weighed using a scale and dry bucket. This specimen checked in at 20 inches and one pound before being released.

Prior to the construction of large dams, American Eels were plentiful in the Susquehanna and its tributaries, including the Conewago. They’ve since been rarities for more than half a century. Now they’re getting a lift.

American Eels serve as an intermediate host for the microscopic parasitic glochidia (larvae) of the Eastern Elliptio (Elliptio complanata), a declining native freshwater mussel of the Lower Susquehanna River Watershed. While feeding on their host (usually in its gills), the glochidia cause little injury and soon drop off to continue growth, often having assured distribution of their species by accepting the free ride. Freshwater mussels are filter feeders and improve water quality. They grow slowly and can live for decades.

American Eels are a catadromous species, starting life as tiny glass eels in the saltwater of the Atlantic Ocean, then migrating to tidal brackish marshes and streams (males) or freshwater streams (females) to mature. This 20-incher probably attempted to ascend the Susquehanna as an elver in 2016 or 2017. After hitching a ride with some friendly folks, she bypassed the three largest dams on the lower Susquehanna (Conowingo, Holtwood, and Safe Harbor) and arrived in the Conewago where she may remain and grow for ten years or more. To spawn, a perilous and terminally fatal journey to the Sargasso Sea awaits her. (You may better know the area of the Sargasso Sea as The Bermuda Triangle…a perilous place to travel indeed!)

SOURCES

Normandeau Associates, Inc. and Gomez and Sullivan. 2018. Muddy Run Pumped Storage Project Conowingo Eel Collection Facility FERC Project 2355. Prepared for Exelon.

Stambaugh, Jr., John W., and Robert P. Denoncourt. 1974. A Preliminary Report on the Conewago Creek Faunal Survey, Lancaster County, Pennsylvania. Proceedings of the Pennsylvania Academy of Sciences. 48: 55-60.

May 29, 2018May 31, 2018

Looking Up

One can get a stiff neck looking up at the flurry of bird activity in the treetops at this time of year. Many of the Neotropical migrants favor rich forests as daytime resting sites after flying through the night. For others, these forests are a destination where they will nest and raise their young.

The Veery (Catharus fuscescens) is a Neotropical thrush that breeds in extensive mature forest on the dampest slopes of the Diabase ridges in the Gettysburg Basin. Their rolling flute-like songs echo through the understory as newly arrived birds establish nesting territories.

The whistled song of the Baltimore Oriole is often heard long before this colorful Neotropical is seen among the foliage of a treetop. Some dead branches allow us a glimpse of this curious beauty.

The “Pee-a-wee……..Pee-urr” song of the Eastern Wood-Pewee (Contopus virens), a small flycatcher, is presently heard in the Riparian Woodlands at Conewago Falls. It breeds in forested tracts throughout the lower Susquehanna valley. The vocalizations often continue through the summer, ending only when the birds depart to return to the tropics for the winter.

While constructing a nest beneath a tree canopy, an Eastern Wood-Pewee form-fits the cup where eggs will soon be laid.

The Yellow-billed Cuckoo (Coccyzus americana) nests in the treetops of Riparian Woodlands along the Susquehanna and its tributaries. Most arrive during the second half of May for their summer stay. It is a renowned consumer of caterpillars.

The Cedar Waxwing is a notorious wanderer. Though not a Neotropical migrant, it is a very late nester. Flocks may continue moving for another month before pairs settle on a place to raise young.

Of the more than twenty species of warblers which regularly migrate through the lower Susquehanna Valley, the Common Yellowthroat (Geothlypis trichas) is among those which breeds here. It is particularly fond of streamside thickets.

For the birds that arrive earlier in spring than the Neotropical migrants, the breeding season is well underway. The wet weather may be impacting the success of the early nests.

Northern Rough-winged Swallows arrived back in April. At traditional nest sites, including the York Haven Dam and local creek bridges, small groups of adults were seen actively feeding and at times perching in dead treetops during recent days. There was an absence of visits to the actual nest cavities where they should be feeding and fledging young by now. It’s very possible that these nests failed due to the wet weather and flooding. Another nest attempt may follow if drier conditions allow stream levels to subside and there is an increase in the mass of flying insects available for the adults to feed to their young..

A Carolina Chickadee, a resident species, is seen atop a hollow stump where it and a mate are constructing a new nest for a second brood. Did the first brood fail? Not sure.

Common Mergansers are an uncommon but regular nesting species of waterfowl on the lower Susquehanna River. They nest in cavities, requiring very large trees to accommodate their needs. It was therefore encouraging to see this pair on a forested stream in northern Lancaster County during the weekend. However, a little while after this photograph was taken the pair flew away, indicating that they are not caring for young which by now should be out of the nest and on the move under the watchful care of the female.

So long for now, if you’ll excuse me please, I have a sore neck to tend to.

February 17, 2018February 17, 2018

A Flock of Seagulls?

At the moment there is a heavy snow falling, not an unusual occurrence for mid-February, nevertheless, it is a change in weather. Forty-eight hours ago we were in the midst of a steady rain and temperatures were in the sixties. The snow and ice had melted away and a touch of spring was in the air.

Big Bluestem in the Riverine Grasslands is inundated by the rising waters of the Susquehanna at Conewago Falls. The river ice has been dispersed by the recent mild temperatures and rains.

Anyone casually looking about while outdoors during these last several days may have noticed that birds are indeed beginning to migrate north in the lower Susquehanna valley. Killdeer, American Robins, Eastern Bluebirds, Red-winged Blackbirds, and Common Grackles are easily seen or heard in most of the area now.

Just hours ago, between nine o’clock this morning and one o’clock this afternoon, there was a spectacular flight of birds following the river north, their spring migration well underway. In the blue skies above Conewago Falls, a steady parade of Ring-billed Gulls was utilizing thermals and riding a tailwind from the south-southeast to cruise high overhead on a course toward their breeding range.

Ring-billed Gulls swarm in a thermal updraft above Conewago Falls to gain altitude prior to streaming off to the north and continuing their journey.

Ring-billed Gulls climbing to heights sometimes exceeding 1,000 feet before breaking off and gliding away to the north.

The swirling hoards of Ring-billed Gulls attracted other migrants to take advantage of the thermals and glide paths on the breeze. Right among them were 44 Herring Gulls, 3 Great Black-backed Gulls, 12 Tundra Swans (Cygnus columbianus), 10 Canada Geese, 3 Northern Pintails (Anas acuta), 6 Common Mergansers, 3 Red-tailed Hawks, a Red-shouldered Hawk, 6 Bald Eagles (non-adults), 8 Black Vultures, and 5 Turkey Vultures.

A first-year Herring Gull (top center) is a standout in a “kettle” of Ring-billed Gulls.

How many Ring-billed Gulls passed by today? More than 18,000…with emphasis on **MORE THAN**. You see, early this afternoon, the handy-dandy clicker-counter used to tick off and tally the big flights of birds as they pass by quit clicking and counting. Therefore, 18,000 is the absolute minimum number of Ring-billed Gulls seen migrating north today. Hopefully the trusty old oil can will get the clicker working again soon.

In the afternoon, the clouds closed in quickly, the flight ended, and by dusk more than an inch of snow was on the ground. Looks like spring to me.

January 14, 2018July 1, 2018

Essential Ice

Two days ago, widespread rain fell intermittently through the day and steadily into the night in the Susquehanna drainage basin. The temperature was sixty degrees, climbing out of a three-week-long spell of sub-freezing cold in a dramatic way. Above the ice-covered river, a very localized fog swirled in the southerly breezes.

By yesterday, the rain had ended as light snow and a stiff wind from the northwest brought sub-freezing air back to the region. Though less than an inch of rain fell during this event, much of it drained to waterways from frozen or saturated ground. Streams throughout the watershed are being pushed clear of ice as minor flooding lifts and breaks the solid sheets into floating chunks.

Today, as their high flows recede, the smaller creeks and runs are beginning to freeze once again. On larger streams, ice is still exiting with the cresting flows and entering the rising river.

Ice chunks on Swatara Creek merge into a dense flow of ice on the river in the distance. Swatara Creek is the largest tributary to enter the Susquehanna in the Gettysburg Basin. The risk of an ice jam impounding the Swatara here at its mouth is lessened because rising water on the river has lifted and broken the ice pack to keep it moving without serious impingement by submerged obstacles. Immovable ice jams on the river can easily block the outflow from tributaries, resulting in catastrophic flooding along these streams.

Fast-moving flows of jagged ice race toward Three Mile Island and Conewago Falls. The rising water began relieving the compression of ice along the shoreline during the mid-morning. Here on the river just downstream of the mouth of Swatara Creek, ice-free openings allowed near-shore piles to separate and begin floating away after 10:30 A.M. E.S.T. Moving masses of ice created loud rumbles, sounding like a distant thunderstorm.

Ice being pushed and heaved over the crest of the York Haven Dam at Conewago Falls due to compression and rising water levels.

Enormous chunks of ice being forced up and over the York Haven Dam into Conewago Falls and the Pothole Rocks below.

Ice scours Conewago Falls, as it has for thousands of years.

The action of ice and suspended abrasives has carved the York Haven Diabase boulders and bedrock of Conewago Falls into the amazing Pothole Rocks.

The roaring torrents of ice-choked water will clear some of the woody growth from the Riverine Grasslands of Conewago Falls.

To the right of center in this image, a motorcar-sized chunk of ice tumbles over the dam and crashes into the Pothole Rocks. It was one of thousands of similar tree-and-shrub-clearing projectiles to go through the falls today.

The events of today provide a superb snapshot of how Conewago Falls, particularly the Diabase Pothole Rocks, became such a unique place, thousands of years in the making. Ice and flood events of varying intensity, duration, and composition have sculpted these geomorphologic features and contributed to the creation of the specialized plant and animal communities we find there. Their periodic occurrence is essential to maintaining the uncommon habitats in which these communities thrive.

Fish Crows *(Corvus ossifragus)* gather along the flooding river shoreline. Soon there’ll be plenty of rubbish to pick through, some carrion maybe, or even a displaced aquatic creature or two to snack upon.

January 1, 2018January 2, 2018

Eighteen, and I Like It

Is this the same Conewago Falls I visited a week ago? Could it really be? Where are all the gulls, the herons, the tiny critters swimming in the potholes, and the leaping fish? Except for a Bald Eagle on a nearby perch, the falls seems inanimate.

Yes, a week of deep freeze has stifled the Susquehanna and much of Conewago Falls. A hike up into the area where the falls churns with great turbulence provided a view of some open water. And a flow of open water is found downstream of the York Haven Dam powerhouse discharge. All else is icing over and freezing solid. The flow of the river pinned beneath is already beginning to heave the flat sheets into piles of jagged ice which accumulate behind obstacles and shallows.