Fish Nurseries in the Susquehanna

Resilient to the pressures of flooding, ice scour, drought, and oft times really poor water quality, Water Willow (Dianthera americana, formerly Justicia americana) is the most common herbaceous plant on the Susquehanna’s non-forested alluvial islands.  Yet, few know this native wildflower by name or reputation.

Water Willow on Alluvial Island
Pure stands of emergent Water Willow endure at times brutal conditions on non-forested islands in the Susquenanna.
Water Willow (foreground) and Black Willow.
Alluvial deposits of sand, clay, gravel, and silt create ideal substrate for mats of Water Willow along shorelines of the Susquehanna and its larger tributaries.  Provided the loose substrate remains moist, this emergent thrives even when water levels retreat during periods of dry weather.  The woody plant in the background, the native Black Willow, shares similar soil preferences but is found growing on slightly higher ground as a non-emergent tree or shrub.  It is a member of the willow family (Salicaceae).
Water Willow in bloom.
In bloom now, the orchid-like flower of the Water Willow is a quick giveaway that it is not a close relative of the willow trees but is instead a member of the acanthus family (Acanthaceae) and is allied with the genus Ruellia, the wild petunias.

The spring of 2024 has been very kind to our beds of Water Willow.  Rainfall in the Susquehanna watershed has been frequent enough to maintain river levels just high enough to keep the roots of the plants wet.  During the interludes in storm activity, dry spells have rolled back any threat of flooding on the river’s main stem, thus eliminating chances of submerging the plants in muddy water and preventing the sun from keeping them warm, happy, and flowering early.  Thundershowers throughout the basin earlier this week have now raised the river a few inches to inundate the base of the plants and make mats of Water Willow favorable places for newly hatched fry and other young fish to take refuge while they grow.  Here’s a look…

Spottail Shiner
The Spottail Shiner (Notropis hudsonius) is a common native minnow of the Susquehanna.  This juvenile was found among several dozen small fish taking refuge in the cover of Water Willow below Conewago Falls.
Mimic Shiner
The Mimic Shiner (Notropis volucellus) is generally regarded to be a native transplant from the Mississippi drainage that has become established in the Susquehanna and many of its tributaries, possibly after introduction by way of bait buckets.  However, the fish tends to be very fragile and dies quickly upon handling, so its use and transport as a bait species may be impractical.  The Mimic Shiner is very common in around Conewago Falls.
Juvenile Mimic Shiner
A juvenile Mimic Shiner less than one inch in length found among flooded Water Willow below Conewago Falls earlier this week.
Juvenile Quillback
One of about a dozen juvenile Quillbacks (Carpiodes cyprinus) found in Water Willow just below Conewago Falls.  For spawning, local populations of this compact native species of carpsucker favor the gravel-bottomed pools among the Jurassic-Triassic boulders of the falls’ pothole rocks.  Probably hatched within the last eight weeks, this specimen was just one inch long.
Spotfin/Satinfin Shiner among Water Willow Rhizomes
As summer progresses, stands of emergent Water Willow begin to expand their size by sending out rhizomes.  Increasing numbers of small fish like this Spotfin/Satinfin Shiner (Cyprinella species) concentrate in the cover of the thickening vegetation.
Spotfin/Satinfin Shiners
The importance of these patches of emergent wildflowers (sounds weird, doesn’t it?) is demonstrated by the numbers of fish gathered within their underwater forest of stems and leaves by summertime.
Spotfin/Satinfin Shiners (Cyprinella species)
To protect them from burial by silt and to prevent them from being swept away by current, spawning Spotfin/Satinfin Shiners deposit their eggs in crevices of submerged rocks and wood, often in or near mats of Water Willow.  Males guard the eggs until hatching.  The fry must then take shelter among boulders, cobble, and plant cover.  Note the breeding-condition male in the upper right.
Green Sunfish
Panfish like this non-native Green Sunfish (Lepomis cyanellus) will often choose nesting sites in deeper water adjacent to beds of Water Willow, particularly if submerged growth like this Water Stargrass adds to the availability of cover for their young after hatching.
Smallmouth Bass
Smallmouth Bass gather in a pool adjacent to a Water Willow-covered island.  These non-native predators rely on beds of these indigenous plants to provide habitat for their young, then, after spawning, lurk in the waters surrounding them to ambush less-than-vigilant minnows and other victims.

By now you’ve come to appreciate the importance of Water Willow to the sustainability of our populations of fish and other aquatic life.  Like similar habitat features that reduce sediment runoff and nutrient pollution, undisturbed stands of terrestrial, emergent, and submerged native plant species are essential to the viability of our freshwater food webs.

Photo of the Day

Long-legged Fly
The minuscule Long-legged Fly (Condylostylus species) is a predatory consumer of soft-bodied invertebrates.  In the headquarters garden, we found this individual and others scurrying around on the leaves of Common Milkweed where they may be seeking to gobble up infesting aphids.

Schools of Juvenile Largemouth Bass Learning to Survive

Yesterday, while photographing damselflies on a rehabilitated segment of a warmwater lower Susquehanna valley stream, we noticed some oddly chunky small fish gathered on the surface of a pool along the shoreline.

Damselflies and Small Fish
Perched damselflies and some sort of robust little fish feeding nearby.

Upon further inspection, they appeared to be fingerlings of some type of sunfish or bass.  Time for a closer look.

Juvenile Largemouth Bass
At just one inch in length, these juvenile Largemouth Bass (Micropterus salmoides) are already showing signs of the dark lateral stripe that so easily identifies the adult fish.
Adult Largemouth Bass on Spawning Bed
Adult Largemouth Bass began spawning among nearby beds of Spatterdock and other emergent and submerged aquatic vegetation about one month ago, just as water temperatures stabilized to a minimum of the low sixties for several days and nights.  Each female can lay thousands of eggs.  Only those that are successfully fertilized by the attending male have a chance to hatch.
Juvenile Largemouth Bass
Largemouth Bass eggs can hatch as soon as ten days after being deposited in the nest by the female and fertilized by the male.  The fry linger in the nest for another week consuming the nutrition contained in their attached yolk sac.
Juvenile Largemouth Bass
The juvenile fish are then ready to leave the nest and begin feeding on zooplankton.
Juvenile Largemouth Bass
Young largemouths often gather in schools to feed in waters near their birthplace.  As they grow, they soon begin consuming small invertebrates and tiny fish.  But for young bass, the hazards are many.  These juveniles can become victims of a host of predatory insects, crayfish, piscivorous birds, and bigger fish.  Then too, Largemouth Bass, like most other species  of fishes, are cannibalistic and will consume others of their own kind.  Of the thousands of eggs produced by a mating pair, natural selection determines which, if any, of their progeny will survive to reproduce and sustain their genetic line.

In the Lower Susquehanna River Watershed, the Largemouth Bass is an introduced species, a native transplant from the Mississippi watershed and Atlantic Slope drainages south of the Chesapeake.

Photo of the Day

Ninebark
The bright-red flower buds of the Ninebark (Physocarpus opulifolius) precede clusters of white blooms that will, in coming weeks, attract a variety of butterflies and other pollinators to this indigenous shrub.  Its peeling bark and colorful deciduous leaves attract interest throughout the year.  In the lower Susquehanna watershed, Ninebark is most frequently found growing along stream banks.  It will often thrive on steep slopes with moist soils, so is useful as an erosion control species as well.  To add it to your refuge’s landscape, look for it at nurseries that stock native plants.  Once there, you’ll find a variety of cultivars that are sure to satisfy even the fussiest of gardeners.

Arboreal Birds and Tent Caterpillars

During the past week, we’ve been exploring wooded slopes around the lower Susquehanna region in search of recently arrived Neotropical birds—particularly those migrants that are singing on breeding territories and will stay to nest.  Coincidentally, we noticed a good diversity of species in areas where tent caterpillar nests were apparent.

Eastern Tent Caterpillar Nest
The conspicuous nest of the Eastern Tent Caterpillar (Malacosoma americanum), a native species of moth.  The first instar of the larval caterpillars hatch in early spring from egg masses laid on the limbs of the host tree by an adult female moth during the previous spring.  Soon after they begin feeding on the host tree’s first tender shoots, these tiny, seldom-noticed larvae start communal construction of a silk tent to act as a shelter and greenhouse-like solar collector that will both provide protection from the elements and expedite their growth.
Eastern Tent Caterpillar
The familiar last instar of the Eastern Tent Caterpillar is the most consumptive stage of the animal’s life.  After feeding in the treetops, they will descend to the ground and seek a sheltered location to pupate.  Adult moths emerge in several weeks to take to the air, mate, and produce eggs to be deposited on a host tree for hatching next year.  The favorite host tree in forests of the Lower Susquehanna River Watershed: native Black Cherry.

Here’s a sample of the variety of Neotropical migrants we found in areas impacted by Eastern Tent Caterpillars.  All are arboreal insectivores, birds that feed among the foliage of trees and shrubs searching mostly for insects, their larvae, and their eggs.

Yellow-throated Vireo
The Yellow-throated Vireo nests, feeds, and spends the majority of its time feeding among canopy foliage.
Eastern Wood-Pewee
The Eastern Wood-Pewee is a flycatcher found in mature woodlands.  It feeds not only among the limbs and leaves, but is an aerial predator as well.
Northern Parula
The Northern Parula nests in mature forests along rivers and on mountainsides, particularly where mature trees are draped with thick vines.
Hooded Warbler
The Hooded Warbler (Setophaga citrina) is found among thick understory growth on forested slopes.
Ovenbird
The Ovenbird builds a domed, oven-like nest on the ground and forages in the canopy.
Kentucky Warbler
The Kentucky Warbler (Geothlypis formosa) nests in woodland undergrowth, often near steep, forested slopes.
Worm-eating Warbler
The Worm-eating Warbler (Helmitheros vermivorum) nests among woody understory growth on forested hillsides.
Scarlet Tanager
The Scarlet Tanager is often difficult to observe because of its affinity for the canopy of mature forest trees.

In the locations where these photographs were taken, ground-feeding birds, including those species that would normally be common in these habitats, were absent.  There were no Gray Catbirds, Carolina Wrens, American Robins or other thrushes seen or heard.  One might infer that the arboreal insectivorous birds chose to establish nesting territories where they did largely due to the presence of an abundance of tent caterpillars as a potential food source for their young.  That could very well be true—but consider timing.

Already Gone-  By the time Neotropical migrants arrive in our area, the larval stages of the Eastern Tent Caterpillar’s life cycle are already coming to an end.  The nests that these native insects constructed to capture the energy of the springtime sun have allowed the larvae to exit and browse foliage when conditions were suitable, then return for shelter when they were not.  While inside, the larvae could move among the chambers of their structure to find locations with a temperature that best suited their needs.  Therein the solar heating and communal warmth sped up digestion and growth.
Eastern Tent Caterpillar
Eastern Tent Caterpillar larvae are now in their bristly final-instar stage and the majority have already moved to the ground to each seek a place to pupate and metamorphose into an adult moth.  Arboreal Neotropical birds have scarcely had a chance to feed upon them, and ground-feeding species seem to lack any temptation.  As for the adult moths, they fly only at night and live for just one day, offering little in the way of food for aerial, arboreal, or ground-feeding birds.
Wild Turkey
Having left arboreal environs, Eastern Tent Caterpillar larvae are now food for ground-feeding birds like our resident Wild Turkeys.  They need only get past the bristly hairs on the caterpillar’s back and the foul taste that may result from its limited diet of cyanogenic Black Cherry leaves.
Yellow-billed Cuckoo
The arboreal Yellow-billed Cuckoo (seen here) and its close relative the Black-billed Cuckoo (Coccyzus erythropthalmus) are the two species of birds in our area known to regularly feed on bristly tent caterpillars.  But having just arrived from the tropics to nest, they’ll need to rely on other insects and their larvae as sources of food for their young.
Black Cherry defoliated by Eastern Tent Caterpillars.
Final-instar Eastern Tent Caterpillars often defoliate Black Cherry trees before moving to the ground to pupate. Their timing allows them to feed on the fresh foliage while it is still young and tender, and to largely avoid becoming food for the waves of Neotropical birds that arrive in the lower Susquehanna basin in May.

So why do we find this admirable variety of Neotropical bird species nesting in locations with tent caterpillars?  Perhaps it’s a matter of suitable topography, an appropriate variety of native trees and shrubs, and an attractive opening in the forest.

American Redstart
An American Redstart singing in a Black Cherry.  Unlike others in the vicinity, this tree nestled among several very large Eastern White Pines showed no signs of tent caterpillar activity.  It may be that for one reason or another, no adult female moth deposited her eggs on this particular tree.  During our visits, Black Cherry was but one of the diverse variety of native trees and shrubs found growing on the sloping topography that created attractive habitat for the nesting birds we found.  We happened to notice that a majority, but not all, of those Black Cherry trees were impacted by Eastern Tent Caterpillars.
Black Cherry in Flower
The end of the Eastern Tent Caterpillar’s larval surge may spell the end of their nests for the year, but it’s not the end for the Black Cherry and other host trees in the Prunus (cherry) and Malus (apple) genera.  Because it’s still early in the season, they have plenty of time to re-leaf and many will still flower and produce fruit.  Those flowers and foliage will attract numerous other insects (including pollinators) that benefit breeding birds.
Blue-winged Warbler
The Blue-winged Warbler inhabits shrubby breaks in the forest such as this utility right-of-way where Black Cherry trees have sprouted after their seeds arrived in waste deposited by fruit-eating (frugivorous) birds.  Already attractive to a variety of insectivores, these openings soon lure egg-laying Eastern Tent Caterpillar moths to the cherry trees growing therein.  Even in dense forest, a small clearing created by a cluster of dead trees makes good bird habitat and will sooner or later be visited by fruit-eating species that will inadvertently sow seeds of Black Cherry, starting yet another stand of host trees for Eastern Tent Caterpillars.  It’s the gap in the forest that often attracts the birds, some of which plant the host trees, which sometimes entice Eastern Tent Caterpillar moths to lay their eggs.
Red-Eyed Vireo
Adapt and Reuse-  A Red-eyed Vireo visits an Eastern Tent Caterpillar nest…
Red-eyed Vireo
…and ignores the few remaining occupants that could easily be seized to instead collect silk to reinforce its own nest.

Here in the Lower Susquehanna River Watershed, the presence of Eastern Tent Caterpillar nests can often be an indicator of a woodland opening, natural or man-made, that is being reforested by Black Cherry and other plants which improve the botanical richness of the site.  For numerous migratory Neotropical species seeking favorable places to nest and raise young, these regenerative areas and the forests surrounding them can be ideal habitat.  For us, they can be great places to see and hear colorful birds.

Scarlet Tanager
Our Lucky Break-  This Scarlet Tanager descended from the treetops to feed on spiders in a small forest clearing.

Photo of the Day

Paulownia in Flower
While in flower, this extensive stand of Princess Trees (Paulownia tomentosa) straddling Second Mountain north of Harrisburg might be mistaken for a series of boulder outcrops.  Native to eastern Asia, the fast-growing Princess Tree has escaped cultivation to become naturalized in many parts of eastern North America.  You’ll currently notice the showy purple blooms on many forested ridges and hilltops throughout the Lower Susquehanna River Watershed.  Paulownia tomentosa is also known as the Phoenix Tree, a name derived from its ability, due to its extensive root system, to regenerate following fire.  This fast-growing invasive therefore calls for measures in addition to prescribed burns for control within infected forests.  Mechanical and/or chemical methods of removal are frequently required.

See Food and an Oriole Doubleheader

The rain and clouds have at last departed.  With blue skies and sunshine to remind us just how wonderful a spring afternoon can be, we took a stroll at Memorial Lake State Park in Lebanon County, Pennsylvania, to look for some migratory birds.

Indigo Bunting
Though running just a few days later than usual, Indigo Buntings have arrived to begin nesting.
Common Loon
This Common Loon dropped by Memorial Lake during a storm several days ago and decided to stay awhile.  It’s a species that winters in oceanic waters along the Atlantic seaboard and nests on glacial lakes to our north.
Common Loon
Because of the low level of turbidity in Memorial Lake, visibility is good enough to allow this benthic feeder an opportunity to see food before expending energy to dive down and retrieve it.  Favorable foraging conditions might be part of the reason this bird is hanging around.
Shoreline Vegetation at Memorial Lake
Clear Water-  Memorial Lake is one of the few man-made lakes in the Lower Susquehanna River Watershed to be appropriately vegetated with an abundance of submerged, floating, and emergent plants.  As a result, the water from Indiantown Run that passes through the impoundment is minimally impacted by nutrient loads and the algal blooms they can cause.  Buffers of woody and herbaceous growth along the lake’s shorelines provide additional nutrient sequestering and help prevent soil erosion and siltation.
Baltimore Oriole
The breeding season has begun for Neotropical migrants including this Baltimore Oriole, which we found defending a nesting territory in a stand of Black Walnut trees.
Orchard Oriole
Along the edge of the lake, this Orchard Oriole and its mate were in yet another stand of tall walnut trees.
Common Nighthawks
Early in the season and early in the day, we started seeing Common Nighthawks flying above wooded areas north of the lake at 4 o’clock this afternoon.  After all the raw and inclement weather they’ve experienced in recent days, the warm afternoon was probably their first opportunity to feed on flying insects in quite a while.
Common Nighthawks
Early birds, Common Nighthawks feeding at 4 P.M.

What?  You thought we were gonna drop in on Maryland’s largest city for a couple of ball games and some oysters, clams, and crab cakes—not likely.

A Pre-dawn Thunderstorm and a Fallout of Migrating Birds

In recent days, the peak northbound push of migratory birds that includes the majority of our colorful Neotropical species has been slowed to a trickle by the presence of rain, fog, and low overcast throughout the Mid-Atlantic States.  Following sunset last evening, the nocturnal flight resumed—only to be grounded this morning during the pre-dawn hours by the west-to-east passage of a fast-moving line of strong thundershowers.  The NOAA/National Weather Service images that follow show the thunderstorms as well as returns created by thousands of migrating birds as they pass through the Doppler Radar coverage areas that surround the lower Susquehanna valley.

Sterling, Virginia, Doppler Radar west of Washington, D.C., at 4:00 A.M. E.D.T. indicates a dense flight of northbound migrating birds located just to the south of the approaching line of rain and thunderstorms over the State College, Pennsylvania, radar coverage area.  (NOAA/National Weather Service image)
More northbound birds are indicated at 4 A.M. by the radar station located at Dover, Delaware…  (NOAA/National Weather Service image)
…and by the Mount Holly, New Jersey, radar site.  (NOAA/National Weather Service image)
Many of the migrating birds shown here over the Binghamton, New York, radar station at 4 A.M. probably overflew the lower Susquehanna region earlier in the night.  (NOAA/National Weather Service image)
And these birds over Albany, New York’s, radar station at 4 A.M. are mostly migrants that passed north over New Jersey and easternmost Pennsylvania last evening and during the wee hours of this morning.  (NOAA/National Weather Service image)

Just after 4 A.M., flashes of lightning in rapid succession repeatedly illuminated the sky over susquehannawildlife.net headquarters.  Despite the rumbles of thunder and the din of noises typical for our urban setting, the call notes of nocturnal migrants could be heard as these birds descended in search of a suitable place to make landfall and seek shelter from the storm.  At least one Wood Thrush and a Swainson’s Thrush (Catharus ustulatus) were in the mix of species passing overhead.  A short time later at daybreak, a Great Crested Flycatcher was heard calling from a stand of nearby trees and a White-crowned Sparrow was seen in the garden searching for food.  None of these aforementioned birds is regular here at our little oasis, so it appears that a significant and abrupt fallout has occurred.

White-crowned Sparrow
A White-crowned Sparrow in the headquarters garden at daybreak.  It’s the first visit by this species in a decade or more.

Looks like a good day to take the camera for a walk.  Away we go!

Gray Catbird
Along woodland edges, in thickets, and in gardens, Gray Catbirds were everywhere today.  We heard and/or saw hundreds of them.
American Redstart
During our travels, American Redstarts were the most frequently encountered warbler.  Look for them in low-lying forested habitats.
Many early-arriving Baltimore Orioles have already begun building nests.  But widespread territorial fighting today may be an indication that some latecomer orioles became trespassers after dropping in on existing territories during the morning fallout.
Red-eyed Vireo
Red-eyed Vireos are difficult to see but easily heard in forested areas throughout the Lower Susquehanna River Watershed.
Scarlet Tanager
If the oriole isn’t the showiest of the Neotropical migrants, then the Scarlet Tanager is certainly a contender…
Scarlet Tanager
Listen for their burry, robin-like song in the treetops of mature upland forests.
Wood Thrush
No woodland chorus is complete without the flute-like harmony of the Wood Thrush.  Look and listen for them in rich forests with dense understory vegetation.
Eastern Wood-Pewee
The Eastern Wood-Pewee, another forest denizen, has an easy song to learn…a series of ascending “pee-a-wee” phrases interspersed with an occasional descending “pee-urr”.  It was one of the few flycatchers we found today, but more are certainly on the way.  Their numbers should peak in coming days.
Yellow-rumped Warbler
Yellow-rumped Warblers can be especially numerous during migration but tend to peak prior to the arrival of the bulk of the Neotropical species.  This was the only “yellow-rump” we encountered today.  The majority have already passed through on their way to breeding grounds to our north.
Common Yellowthroat
If today you were to visit a streamside thicket or any type of early successional habitat, you would probably find this perky little warbler there, the Common Yellowthroat.
Yellow Warbler
The Yellow Warbler likes streamside thickets too.  You can also find them along lakes, ponds, and wetlands, especially among shrubby willows and alders.
White-crowned Sparrow
While nowhere near the headquarters garden, we ran into another White-crowned Sparrow in less-than-ideal habitat.  This one was in a row of trees in a paved parking lot.
Bobolink
Not all songbirds migrate at night. The Bobolink is an example of a diurnal (day-flying) migrant.  They’re currently arriving in hay fields that are spared the mower until after nesting season.
Blue-gray Gnatcatcher
While looking for Neotropical species and other late-season migrants, we also found numerous early arrivals that had already begun their breeding cycles.  We discovered this Blue-gray Gnatcatcher on its nest in a Black Walnut tree…
Blue-gray Gnatcatcher
…then, later in the day, we found this one in its nest, again in a Black Walnut tree.  Note the freshly emerging set of leaves and flower clusters.  With many tree species already adorned in a full set of foliage, open canopies in stands of walnuts we found growing in reforested areas seemed to be good places to see lots of migrants and other birds today.  It’s hard to say whether birds were more numerous in these sections of woods or were just easier to observe among the sparse leaf cover.  In either case, the nut-burying squirrels that planted these groves did us and the birds a favor.

There’s obviously more spring migration to come, so do make an effort to visit an array of habitats during the coming weeks to see and hear the wide variety of birds, including the spectacular Neotropical species, that visit the Lower Susquehanna River Watershed each May.  You won’t regret it!

Wood Ducks
Wood Ducks arrived in February and March to breed in the lower Susquehanna valley.  Soon after hatching in April or May, the young leave the nest cavity to travel under the watchful gaze of their ever-vigilant mother as they search for food along our local waterways.  If you’re fortunate, you might catch a glimpse of a brood and hen while you’re out looking at the more than one hundred species of birds that occur in our region during the first half of May.  Good luck!

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
Prescribed fires are typically planned for the dormant season extending from late fall into early spring with burns best conducted on days when the relative humidity is low.
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 at Fort Indiantown Gap
Prescribed fires replace the periodic natural burns that would normally reduce the fuel load in forested areas.  Where these fuels are allowed to accumulate, south-facing slopes are particularly susceptible to extreme fires due to their exposure to the drying effects of intense sunlight for much of the year.  The majority of small oaks subjected to treatment by the prescribed fire shown here will have the chance to regenerate without immediate competition from other species including invasive plants.  The larger trees are mostly unaffected by the quick exposure to the flames.  Note too that these fires don’t completely burn everything on the forest floor, they burn that which is most combustible.  There are still plenty of fallen logs for salamanders, skinks, and other animals to live beneath and within.

 

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.
Grasshopper Sparrow
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…
Ring-necked Pheasant
…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.
Buck Moth
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.
Leaves of the Bear Oak in fall.  The Bear Oak regenerates readily from top kill caused by fire.
Reed Canary Grass
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.
Prescribed Fire
A mowed strip of cool-season grasses along the perimeter of the burn area is already green and functions as an ideal fire break.  While the drip torch is perfect for lighting combustibles along the fire’s perimeter, the paintball gun-looking device is an effective tool used to lob incendiaries into the center areas of the burn zone for ignition.
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.
Great Spangled Fritillary
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.
Eastern Tiger Swallowtails on Joe-pye Weed.
And later in the summer, Eastern Tiger Swallowtails on Joe-pye Weed.
Indiangrass in flower in mid-summer.
Indiangrass in flower in mid-summer.
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.

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

Common Winterberry
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.
Pin Oak
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.
Purple Coneflower
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

Eastern Redbud
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

Yellow Poplar
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.
Eastern Red Cedar
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.
Common Winterberry
Lebanon County Conservation District is offering Common Winterberry and Eastern White Pine during their 2024 Tree and Plant Sale.  Plant them both for striking color during the colder months.  Eastern White Pine is also available from the Cumberland, Dauphin, Lancaster, and York County sales.

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!

Birds Beginning to Wander

Since Tuesday’s  snow storm, the susquehannawiildlife.net headquarters garden continues to bustle with bird activity.

Northern Mockingbird
Our Northern Mockingbird remains ever vigilant in its attempts to discourage American Robins and Eastern Bluebirds from feeding on the berry crop.  Slowly, the latter species are winning the contest.
Carolina Chickadee feeding on sunflower seed.
A Carolina Chickadee carefully dissects a sunflower seed to snack on the nutritious kernel.
Red-bellied Woodpecker
This beauty shows us that yes, Red-bellied Woodpeckers do indeed have red bellies.
American Robin eating Common Winterberry fruits.
Getting energized for a big move north, the robins keep on gulping berries.

Today, there arrived three species of birds we haven’t seen here since autumn.  These birds are, at the very least, beginning to wander in search of food.  Then too, these may be individuals creeping slowly north to secure an advantage over later migrants by being the first to establish territories on the most favorable nesting grounds.

Song Sparrow
This Song Sparrow is the first we’ve seen in the garden since sometime last fall.  Is it working its way north or did it just come to town in search of food?
Northern Flicker
Northern Flickers regularly spend the winter in small numbers in the Lower Susquehanna River Watershed.  This is the first one we’ve had visit the garden since late last autumn.
Fish Crows feeding on Eastern Red Cedar berries.
Fish Crows, seen here feeding on the fruits adorning an Eastern Red Cedar, have returned after being absent in our neighborhood since November.  In coming weeks, both they and the more numerous American Crows that remained through winter will begin constructing nests in nearby trees.

They say the early bird gets the worm.  More importantly, it gets the most favorable nesting spot.  What does the early birder get?  He or she gets out of the house and enjoys the action as winter dissolves into the miracle of spring.  Do make time to go afield and marvel a bit, won’t you?  See you there!

Robins in a Snowstorm

In mid-February each year, large numbers of American Robins descend upon the susquehannawildlife.net headquarters garden to feast on the ripe fruits that adorn several species of our native shrubs and trees.  This morning’s wet snowfall provided the needed motivation for these birds and others to make today the big day for the annual feeding frenzy.

American Robins
Early this morning, branches and limbs in the headquarters garden were loaded with clinging snow and more than one hundred American Robins.
American Robin
To have first grabs at suitable nesting sites, early American Robins are currently beginning to edge their way north.  Spring migration is underway.
American Robin feeding on Common Winterberry
The fruits of Common Winterberry are always a favorite of visiting robins.
Northern Mockingbird
After selfishly guarding the garden’s berries through the entire season, our Northern Mockingbird finds chasing more than one hundred robins away from its food supply an impossible task.
American Robin
This and other visiting robins will strip the winterberry, cedar, American Holly, and other fruit-producing shrubs and trees within a day or two.  To survive what remains of the season, our resident mockingbird will have to look elsewhere for provisions.
American Robin
Another American Robin devouring winterberry fruit.
American Robin
In addition to robins, there were, of course, other guests in the garden refuge on this snowy day.
Red-bellied Woodpecker
This Red-bellied Woodpecker tries to make sense of all the commotion.
Carolina Chickadee
A pair of Carolina Chickadees established a family in the garden during the spring of 2023.  At least five of the birds still stop by on a daily basis.
American Goldfinches
As spring nears, our American Goldfinches are beginning to show a hint of their bright breeding colors.
Blue Jay
A Blue Jay peeks out from the cover of the Eastern Hemlocks.
Carolina Wren
Our Carolina Wrens sing throughout the winter,…
Mourning Dove
…but today we noticed that this Mourning Dove has begun softly cooing to charm a mate…
House Finch
…and the male House Finches are warbling away with the sounds of spring.
Female Eastern Bluebird
With the local mockingbird busily harassing robins, our Eastern Bluebirds went unmolested long enough to stop by…
Bluebird Feeder
…for some raisins from their enclosed feeder.
Male Eastern Bluebird
A showy male Eastern Bluebird on a snowy day in the garden.  Spring must be just around the corner!

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…
Eastern Gray Squirrel
…but did nothing to unnerve our resident Eastern Gray Squirrels,…
Eastern Gray Squirrel
…which promptly went into tail-waving mode to advertise their presence.
Red-tailed Hawk
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…
Red-shouldered Hawk
…and this young Red-shouldered Hawk, an uncommon bird of prey most often found in wet woods and other lowlands.
Eastern Gray Squirrel
To escape notice during visits by these larger raptors, our squirrels remained motionless and commenced performance of their best bump-on-a-log impressions.
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…
White-crowned Sparrow
…a flock of White-crowned Sparrows, most in first-winter plumage…
American Tree Sparrow
…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.
Skunk Cabbage
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.

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.

Song Sparrow
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.
American Robin
Thousands of American Robins have been widespread throughout the lower Susquehanna valley during the past week.  Due to the mild weather during this late fall and early winter, some may still be in the process of working their way south.  Currently, many robins are concentrated along the river shoreline where receding water has exposed unfrozen soils to provide these birds with opportunities for finding earthworms (Lumbricidae) and other annelids.
Golden-crowned Kinglet
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.
Brown Creeper
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
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.
An American Pipit on a bitterly cold afternoon along the Susquehanna.

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.
Song Sparrow
Hundreds of Song Sparrows were found in the grasses and thickets at both locations.
White-throated Sparrow
White-throated Sparrows were also abundant, but prefer the tangles and shrubs of the thickets.
Northern Mockingbird
Northern Mockingbirds were vigilantly guarding winter supplies of berries in the woodlots and hedgerows.
Swamp Sparrow
In grasses and tangles on wetter ground, about a dozen Swamp Sparrows were discovered.
White-crowned Sparrow
The adult White-crowned Sparrow is always a welcome find.
White-crowned Sparrow
And seeing plenty of juvenile White-crowned Sparrows provides some assurance that there will be a steady stream of handsome adult birds arriving to spend the winter during the years to come.
Dark-eyed Junco
Dark-eyed Juncos were encountered only in the vicinity of trees and large shrubs.
Savannah Sparrow
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.
Winter Wren
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.
Red-bellied Woodpecker
This Red-bellied Woodpecker and about a dozen others were found in trees left standing in the project areas.
Yellow-bellied Sapsucker
A Yellow-bellied Sapsucker soaks up some sun.
Pileated Woodpecker
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.

Pileated Woodpecker

Northern Harrier
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.
Northern Harrier
It was a fitting end to a very short, but marvelously sunny, early winter day.

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.
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.
Great Blue Heron
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.
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.

Photo of the Day

Wildflower Meadow Project underway at East Donegal Riverfront Park
Here’s something to look forward to in the new year.  The good citizens of East Donegal Township in Lancaster County have partnered with Alliance for the Chesapeake Bay to establish an extensive wildflower meadow on what had been a mowed field of turf grass at Riverside Park in the Susquehanna floodplain near Marietta.  As the photo shows, the lawn plants have been eliminated in preparation for seeding with a diverse assortment of native grasses and wildflowers to provide habitat for birds and pollinators including butterflies, bees, and other insects.  Once established, the meadow’s extensive vegetative growth will help reduce stormwater runoff by better infiltrating rainfall to recharge the aquifer.  During flood events, the plantings will provide soil stabilization and increase the ability of the acreage to uptake nutrients, thus reducing the negative impact of major storms on the quality of water in the river and in Chesapeake Bay.  Check the project’s progress by stopping by from time to time in 2024!

Photo of the Day

Green Frog on Christmas
It’s been a green Christmas at susquehannawildlife.net headquarters.  Among thick growth of Lesser Duckweed and other aquatic plants in the garden ponds, the Green Frogs and their tadpoles remain active.  The water’s open…still no ice here.

Time to Eat

A glimpse of the rowdy guests crowding the Thanksgiving Day dinner table at susquehannawildlife.net headquarters…

White-breasted Nuthatch
A male White-breasted Nuthatch visits a peanut feeder…
White-breasted Nuthatch
…soon to be joined by a female White-breasted Nuthatch.
Downy Woodpecker
A male Downy Woodpecker gets a bill full of suet.
Carolina Wren
A Carolina Wren nibbles at a peanut.
Eastern Gray Squirrel
An Eastern Gray Squirrel stuffs itself on peanuts dropped by the birds.
Northern Mockingbird
A territorial Northern Mockingbird stands guard over its supply of Common Winterberry fruit.
Eastern Bluebird
To avoid the mockingbird’s aggression, the Eastern Bluebirds opted out of fresh fruit in favor of raisins offered at the feeders.
American Robin
This persistent American Robin has made an art of repeatedly sneaking in to quickly devour a few berries before being chased away by the vigilant mockingbird.
Dark-eyed Junco
After everyone has had their fill, Dark-eyed Juncos clean up the leftovers.

Getting a Head Start on Spring

Recently, we found these Chestnut Oak acorns setting roots into the leaf litter to secure their place among the plants that will turn the forest understory green in the spring.  Individual acorns that germinate soon after falling to the ground in autumn may avoid becoming food for squirrels, turkeys, deer, and other wildlife, thus increasing their chances of surviving to later become adult trees able to produce acorns that pass this quick-development trait to yet another generation of oaks.

Photo of the Day

Blue Wood Aster (Symphyotrichum cordifolium)
Among the hardy wildflowers still in bloom in the forests of the lower Susquehanna valley is the Blue Wood Aster (Symphyotrichum cordifolium), a variable species also known as the Heart-leaved Aster.

Photo of the Day

It looks like Uncle Tyler Dyer had a fun-filled Halloween.  Earlier this afternoon, we caught him drifting off into a nap during his work to make updates to his leaf scans.  As he snoozed away, we found these lying on the floor next to his easy chair and decided to lend a hand by adding them to his collection.  We’ll see how long it takes him to discover our dirty little deed.  You can have a look at our mischief by clicking on the “Trees, Shrubs, and Woody Vines” tab at the top of this page.

If You’re Out Collecting Sweets, It Pays to Look Scary

Only fools mess around with bees, wasps, and hornets as they collect nectar and go about their business while visiting flowering plants.  Relentlessly curious predators and other trouble makers quickly learn that patterns of white, yellow, or orange contrasting with black are a warning that the pain and anguish of being zapped with a venomous sting awaits those who throw caution to the wind.  Through the process of natural selection, many venomous and poisonous animals have developed conspicuously bright or contrasting color schemes to deter would-be predators and molesters from making such a big mistake.

"Red Eft"
The brilliant colors of the “Red Eft”, the terrestrial sub-adult stage of the aquatic Eastern Newt (Notophthalmus viridescens), provide protection not as a form of camouflage, but as a warning to potential predators that “I am inedible” due to the presence of tetrodotoxin, a strong neurotoxin.  Over the generations, natural selection has better enabled the brightest of the individual “Red Efts” to survive to adulthood and reproduce.  Meanwhile, those efts that provided a less obvious visual clue to their toxicity frequently allowed their pursuer to learn of their defense mechanism by the taste-test method.  As one might expect, far fewer of these latter individuals survived to breed and pass along their more cryptic color variation.

Visual warnings enhance the effectiveness of the defensive measures possessed by venomous, poisonous, and distasteful creatures.  Aggressors learn to associate the presence of these color patterns with the experience of pain and discomfort.  Thereafter, they keep their distance to avoid any trouble.  In return, the potential victims of this unsolicited aggression escape injury and retain their defenses for use against yet-to-be-enlightened pursuers.  Thanks to their threatening appearance, the chances of survival are increased for these would-be victims without the need to risk death or injury while deploying their venomous stingers, poisonous compounds, or other defensive measures.

European Paper Wasp
Armed and Dangerous  The yellow-and-black color pattern on this European Paper Wasp signals a potential aggressor that they have come upon a social insect and could be struck with a venomous sting.  The warning colors alone may be all the defenses necessary for this wasp to survive an otherwise fatal encounter.

One shouldn’t be surprised to learn that over time, as these aforementioned venomous, poisonous, and foul-tasting critters developed their patterns of warning colors, there were numerous harmless animals living within close association with these species that, through the process of natural selection, acquired nearly identical color patterns for their own protection from predators.  This form of defensive impersonation is known as Batesian mimicry.

Let’s take a look at some examples of Batesian mimicry right here in the Lower Susquehanna River Watershed.

Suppose for a moment that you were a fly.  As you might expect, you would have plenty to fear while you spend your day visiting flowers in search of energy-rich nectar—hundreds of hungry birds and other animals want to eat you.

Greenbottle Fly
You might not hurt a fly, but plenty of other creatures will.  This Greenbottle Fly relies upon speed and maneuverability to quickly flee predators.
Common Flesh Fly (Sarcophaga species)
Like the Greenbottle Fly, the Common Flesh Fly (Sarcophaga species) needs to be constantly vigilant and survives by being quick to the wing.

If you were a fly and you were headed out and about to call upon numerous nectar-producing flowers so you could round up some sweet treats, wouldn’t you feel a whole lot safer if you looked like those venomous bees, wasps, and hornets in your neighborhood?  Wouldn’t it be a whole lot more fun to look scary—so scary that would-be aggressors fear that you might sting them if they gave you any trouble?

Suppose Mother Nature and Father Time dressed you up to look like a bee or a wasp instead of a helpless fly?  Then maybe you could go out and collect sweets without always worrying about the bullies and the brutes, just like these flies of the lower Susquehanna  do…

FLOWER FLIES/HOVER FLIES

The Common Drone Fly (Eristalis Tenax) is a Honey Bee mimic
The Common Drone Fly (Eristalis tenax) is an unarmed Honey Bee mimic.  This one is gathering nectar on goldenrod flowers.
Transverse Flower Fly (Eristalis transversa)
The Transverse Flower Fly (Eristalis transversa) is another bee mimic.  Members of the genus Eristalis scavenge carcasses in aquatic habitats.  Their larvae are known as rat-tailed maggots, a name that references their long siphons used for breathing surface air while submerged in ponds, streams, and wetlands.
Spilomyia species Flower Fly
Flower flies of the genus Spilomyia are convincing mimics of temperamental yellowjacket wasps.
Yellowjacket Hover Fly
The Yellowjacket Hover Fly (Milesia virginiensis) is usually heard long before it is seen.  It will often approach people and persist with a loud buzzing, sounding more like a bee than a bee does.  Scary, isn’t it?
 Maize Calligrapher
The Maize Calligrapher (Toxomerus politus) is a hover fly mimic of wasps.  Seen here on Indiangrass, it is believed to associate primarily with Corn (Zea mays).
The Narrow-headed Marsh Fly (Helophilus fasciatus) is a wasp mimic.
The Narrow-headed Marsh Fly (Helophilus fasciatus) is a wasp mimic.  Like other mimics of hymenopterans, they are important pollinators of flowering plants.
Syrphus species Hoverfly
This hover fly of the genus Syrphus is another wasp mimic.

TACHINID FLIES

The Feather-legged Fly (Trichopoda species) is a wasp mimic.
The Feather-legged Fly (Trichopoda species) is a wasp mimic.   Its larvae are parasitoids of stink bugs and leaf-footed bugs.

BEE FLIES

Bee Fly (Exoprosopa species)
Bee flies of the genus Exoprosopa convincingly resemble bumble bees.
Bee Fly (Exoprosopa species)
The larvae of Exoprosopa bee flies are believed to be parasitic on the larvae of the parasites of bee and wasp larvae that mature in the soil.  Confused yet?

So let’s review.  If you’re a poor defenseless fly and you want to get your fair share of sweets without being gobbled up by the beasts, then you’ve got to masquerade like a strongly armed member of a social colony—like a bee, wasp, or hornet.  Now look scary and go get your treats.  HAPPY HALLOWEEN!

Visit South Mountain for the Brightest Foliage Display You’ve Ever Seen

Where should you go this weekend to see vibrantly colored foliage in our region?  Where are there eye-popping displays of reds, oranges, yellows, and greens without so much brown and gray?  The answer is Michaux State Forest on South Mountain in Adams, Cumberland, and Franklin Counties.

South Mountain is the northern extension of the Blue Ridge Section of the Ridge and Valley Province in Pennsylvania.  Michaux State Forest includes much of the wooded land on South Mountain.  Within or adjacent to its borders are located four state parks: King’s Gap Environmental Education Center, Pine Grove Furnace State Park, Caledonia State Park, and Mont Alto State Park.  The vast network of trails on these state lands includes the Appalachian Trail, which remains in the mountainous Blue Ridge Section all the way to its southern terminus in Georgia.

Pennsylvania State Parks on South Mounatin
In Pennsylvania, the forested highlands of the Blue Ridge Section of the Ridge and Valley Province are known as South Mountain.  Much of South Mountain lies within the boundaries of Michaux State Forest.  Stars indicate the locations of 1) King’s Gap Environmental Education Center, 2) Pine Grove Furnace State Park, 3) Caledonia State Park, and 4) Mont Alto State Park.  A drive on US 30 between Gettysburg and Chambersburg will take you right through Michaux State Forest along an east to west axis while a scenic northbound or southbound trip along PA 233 will bring you in proximity to each of the state parks located therein.  (Base image from NASA Earth Observatory Collection)

If you want a closeup look at the many species of trees found in Michaux State Forest, and you want them to be labeled so you know what they are, a stop at the Pennsylvania State University’s Mont Alto arboretum is a must.  Located next door to Mont Alto State Park along PA 233, the Arboretum at Penn State Mont Alto covers the entire campus.  Planting began on Arbor Day in 1905 shortly after establishment of the Pennsylvania State Forest Academy at the site in 1903.  Back then, the state’s “forests” were in the process of regeneration after nineteenth-century clear cutting.  These harvests balded the landscape and left behind the combustible waste which fueled the frequent wildfires that plagued reforestation efforts for more than half a century.  The academy educated future foresters on the skills needed to regrow and manage the state’s woodlands.

Online resources can help you plan your visit to the Arboretum at Penn State Mont Alto.  More than 800 trees on the campus are numbered with small blue tags.  The “List of arboretum trees by Tag Number” can be downloaded to tell you the species or variety of each.  The interactive map provides the locations of individual trees plotted by tag number while the Grove Map displays the locations of groups of trees on the campus categorized by region of origin.  A Founder’s Tree Map will help you find some of the oldest specimens in the collection and a Commemorative Tree Map will help you find dedicated trees.  There is also a species list of the common and scientific tree names.

Yellow Buckeye
The Yellow Buckeye (Aesculus flava) is a tree found in the forests of the Blue Ridge Section of the Ridge and Valley Province in West Virginia, Virginia, North Carolina and Georgia.  You can see it in Pennsylvania by visiting the collection of trees in the Arboretum at Penn State Mont Alto.
American Chestnut
The American Chestnut can be difficult to find due to the impact of chestnut blight, but you can see it in the Arboretum at Penn State Mont Alto.
Shagbark Hickory
Shagbark Hickory is a common tree in the forests of South Mountain.
Sweet Cherry
The Sweet Cherry (Prunus avium), a native of Europe, is naturalized throughout eastern and south-central Pennsylvania and is one of the more than 150 species of trees in the arboretum’s collection.
Sweet Birch
Sweet Birch (Betula lenta) foliage is particularly bright yellow on South Mountain this autumn.  It really “pops” against the backdrop of the evergreen Eastern White Pines and Eastern Hemlocks.  During less-than-ideal years, Sweet Birch leaves can subtly transition from green to drab brown without much fanfare before falling.
Common Persimmon
You might have a difficult time finding a Common Persimmon (Diospyros virginiana) growing wild in Pennsylvania, but you can find it in the Arboretum at Penn State Mont Alto.

The autumn leaves will be falling fast, so make it a point this weekend to check out the show on South Mountain.

Late Season Ruby-throated Hummingbirds…Again

Last October 3rd, a late-season Ruby-throated Hummingbird stopped by the garden at susquehannawildlife.net headquarters to take shelter from a rainy autumn storm.  It was so raw and chilly that we felt compelled to do something we don’t normally do—put out the sugar water feeder to supplement the nectar produced by our fall-flowering plants.  After several days of constant visits to the feeder and the flowers, our lingering hummer resumed its southbound journey on October 7th.

Fast forward to this afternoon and what do you know, at least two migrating hummingbirds have stopped by to visit the flowers in our garden.  This year, we have an exceptional abundance of blooms on some of their favorite plants.  In the ponds, aquatic Pickerelweed is topped with purple spikes and we still have bright orange tubular flowers on one of our Trumpet Vines—a full two to three months later than usual.

Late-season Ruby-throated Hummingbird
We checked each of our late-season visitors carefully to be reasonably certain that none was a stray western species of hummingbird.  All appear to be female or juvenile “Ruby-throats”.  If you have an abundance of flowering plants and/or you’re going to maintain your hummingbird feeders through the coming weeks, be on the lookout for western species.  Most are more hardy than our Ruby-throats and some have remained in the lower Susquehanna valley through the winter.
Ruby-throated Hummingbird at Mexican Cigar
As is typically the case, Ruby-throated Hummingbirds quickly gravitate toward the tubular flowers of our Cuphea ignea, the Mexican Cigar.  They find these showy plants to be absolutely irresistible.
Ruby-throated Hummingbird at Mexican Cigar
Mexican Cigar grows wild in parts of the Ruby-throated Hummingbird’s winter range.  To them, it’s comfort food.
Ruby-throated Hummingbird at Bat-faced Cuphea
We’re trying some new cultivars of Cuphea to see how they do.  As this composite image shows, the hummingbirds won’t let our Bat-faced Cuphea (Cuphea llavea) alone.  It’s another plant native to Mexico and Central America, right where some of our hummingbirds spend the winter.

Remember, keep those feeders clean and the provisions fresh!  You’ll be glad you did.

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

Great Black Wasp on goldenrod (Solidago species)
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.
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
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.
Black-and-yellow Mud Dauber at nest.
A Black-and-yellow Mud Dauber at nest.
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.
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

Cuckoo Wasp
Cuckoo Wasps (Chrysididae), also known as Emerald Wasps, parasitize the nests of other species of wasps.  Females lay their eggs inside the host’s nest, then flee the scene.  Upon hatching, larval Cuckoo Wasps feed on stockpiles of prey intended for the host species’ offspring.  Like the adult mud daubers that have already matured and departed this nest by digging a hole through the wall of the cell within which they were hatched, the metallic green Cuckoo Wasp in the upper left has just emerged in much the same way.

SWEAT BEES

A Sweat Bee (Lasioglossum species).
A Sweat Bee (Lasioglossum species) collecting nectar and pollen on White Snakeroot (Ageratina altissima).
A Sweat Bee (Lasioglossum species).
Sweat Bees (Lasioglossum species) visit human skin to lick up the electrolytes left behind by evaporating perspiration.
A Sweat Bee (Lasioglossum species).
Sweat Bees  in the genus Lasioglossum demonstrate various social behaviors ranging from species that are solitary nesters to those that create colonies with work forces ranging in size from as few as four to as many as hundreds of bees.  Some Lasioglossum practice kleptoparasitism, while others are quite accomplished foragers.
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.
An Augochlorine Green Sweat Bee (Augochlorini).
An Augochlorine Green Sweat Bee (Augochlorini).  Sweat bees nest in subterranean cavities and in hollowed out sections of trees.
An Augochlorine Green Sweat Bee (Augochlorini).
A copper-colored Augochlorine Green Sweat Bee (Augochlorini) collecting nectar and dusted with pollen.

LEAFCUTTER AND MASON BEES

Leafcutter Bee
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.
Leafcutter Bee
A Leafcutter Bee (Megachile species) collecting nectar from White Snakeroot.
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.
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

Common Eastern Bumble Bee
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.
Common Eastern Bumble Bees
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.
Eastern Carpenter Bee
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

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

PAPER WASPS

Northern Paper Wasp
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
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.
European Paper Wasp
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
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.
An Eastern Yellowjacket.
A subterranean colony of Eastern Yellowjackets is started anew each spring by a young queen that has survived winter hibernation in diapause, a state of interrupted development.  She constructs the new nest’s first cells using pulp made by chewing rotting wood.  The first brood of workers scales up construction while the queen continues producing eggs.  At the nest, these social insects will viciously attack anyone or anything perceived to be a threat, so give them their space and leave them alone.  Many yellowjacket infestations of homes and other buildings are the work of non-native German Yellowjacket (Vespula germanica) [not shown], an invasive species that constructs paper nests in void spaces including walls and attics.
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
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

Field Ants (Formica species, possibly Formica pallidefulva) clearing the entrance to their underground nest.
Field Ants (Formica species, possibly Formica pallidefulva) clear the entrance to their underground nest.  Field ants are eusocial insects, they work in concert to build, maintain, and defend the nest, rear young, and find food.  There is no social caste system.  Field Ants are predators and scavengers when collecting protein.  For carbohydrates they often rely on the honeydew produced by aphids.  As a method of improving and sustaining the production of honeydew, some ant species will tend colonies of aphids by moving the younger individuals from depleted portions of plants to more healthy tissue.  Field Ant nests contain chambers used for a variety of functions including raising young and storing food.  Some nests include multiple queens and some colonies consist of more than one nest.   Ants in the genus Formica are weaponized; they can spray formic acid to repel intruders and defend their colony.

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.

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!)

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
The Carolina Grasshopper, also known as the Carolina Locust or Quaker, is one of the band-winged grasshoppers.  It is commonly found along roadsides and on other bare ground near stands of tall grass and broadleaf plants.
Carolina Grasshopper
The Carolina Grasshopper is variable in color, ranging from very dark brown…
Carolina Grasshopper
…to a rich tan or khaki shade.  These earth-tone colors provide the insect with effective camouflage while spending time on the ground.
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

Differential Grasshopper nymph.
Differential Grasshopper nymph with small “fairy wings”.
Differential Grasshopper
An adult female Differential Grasshopper with fully developed wings.
An adult female Differential Grasshopper
An adult female Differential Grasshopper

TWO-STRIPED GRASSHOPPER

Melanoplus bivittatus

Two-striped Grasshopper nymph.
An early-stage Two-striped Grasshopper nymph.
Two-striped Grasshopper nymph.
A Two-striped Grasshopper nymph in a later stage.
Two-striped Grasshopper
An adult female Two-striped Grasshopper.
Two-striped Grasshopper
An adult female Two-striped Grasshopper.  Note the pale stripe originating at each eye and joining near the posterior end of the wings to form a V-shaped pattern.
Two-striped Grasshopper
An adult female Two-striped Grasshopper.

RED-LEGGED GRASSHOPPER

Melanoplus femurrubrum

A Red-legged Grasshopper hiding in dense urban vegetation.
An adult male Red-legged Grasshopper hiding in dense urban vegetation.
Red-legged Grasshopper
The Red-legged Grasshopper may currently be our most abundant and widespread species.
Red-legged Grasshopper
An adult male Red-legged Grasshopper.
Red-legged Grasshopper
An adult female Red-legged Grasshopper.

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.

Beginning in the early 1930s, the Western 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 Western 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)
During the summer and early fall, juvenile and adult Ring-necked Pheasants feed heavily on grasshoppers.  Earlier and more frequent mowing along with declining numbers of grasshoppers on farmlands due to an increase in pesticide use were factors contributing to the crash of the pheasant population in the early 1980s.
Wild Turkey
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.
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.
Early Successional Growth
Maintaining areas bordering roads, forests, wetlands, farmlands, and human development in a state of early succession can provide and ideal mix of mature grasses and broadleaf plants for grasshoppers, pollinators, birds, and other wildlife.

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 Pond
Vegetation surrounding the inundated floodplain helps sequester nutrients and sediments to purify the water while also providing excellent wildlife habitat.
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 male Common Whitetail dragonfly keeping watch over his territory.
A Twelve-spotted Skimmer perched on Soft Rush.
A Twelve-spotted Skimmer perched on Soft Rush.
A Blue Dasher dragonfly seizing a Fall Field Cricket (Gryllus pennsylvanicus).
A Blue Dasher dragonfly seizing a Fall Field Cricket (Gryllus pennsylvanicus).
A Spicebush Swallowtail visiting Cardinal Flower.
A Spicebush Swallowtail visiting a Cardinal Flower.
Green Heron
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.
Solitary Sandpiper
A Solitary Sandpiper.
A Solitary Sandpiper testing the waters for proper feeding depth.
A Solitary Sandpiper testing the waters for proper feeding depth.
Pectoral Sandpiper
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!

Photo of the Day

Magnolia Leaf-footed Bug
At first glance, this insect might be mistaken for a Brown Marmorated Stink Bug.  It is, however, a native species, a Magnolia Leaf-footed Bug (Leptoglossus fulvicornis).  Because it feeds almost exclusively on trees in the genus Magnolia, and because the three members of the genus native to the lower Susquehanna valley, Umbrella Magnolia (M. tripetala), Cucumber Tree (M. acuminata), and Sweetbay (M. virginiana), each have a very limited distribution here, this insect’s presence in the watershed is largely dependent on widespread introductions of ornamental magnolias and native transplants including Southern Magnolia (Magnolia grandiflora).  Adult Magnolia Leaf-footed Bugs overwinter in leaf litter beneath the host trees.  In spring, females lay their eggs in rows along the midrib of the leaves where they are often victims of parasitoid wasps including Gyron pennsylvanicum.  The surviving nymphs and the adults feed on the tree’s leaves and fruits, causing little harm to its overall health.

Surf’s Up: The Waves Keep Rolling In

“Waves” of warblers and other Neotropical songbirds continue to roll along the ridgetops of southern Pennsylvania.  The majority of these migrants are headed to wintering habitat in the tropics after departing breeding grounds in the forests of southern Canada.  At Second Mountain Hawk Watch, today’s early morning flight kicked off at sunrise, then slowed considerably by 8:30 A.M. E.D.T.  Once again, in excess of 400 warblers were found moving through the trees and working their way southwest along the spine of the ridge.  Each of the 12 species seen yesterday were observed today as well.  In addition, there was a Northern Parula and a Canada Warbler.  Today’s flight was dominated by Bay-breasted, Blackburnian, Black-throated Green, and Tennessee Warblers.

A Blackburnian Warbler at sunrise on Second Mountain.
A Blackburnian Warbler at sunrise on Second Mountain.
A hungry Blackburnian Warbler feeding on insects.
A hungry Blackburnian Warbler feeding on insects.
Black-throated Green Warbler on Second Mountain.
Black-throated Green Warblers were a plentiful species among both yesterday’s and today’s waves of Neotropical migrants.
A juvenile Black-throated Green Warbler on Second Mountain
A juvenile Black-throated Green Warbler.
Tennessee Warbler on Second Mountain.
One of the scores of Tennessee Warblers seen on Second Mountain early this morning.
Cape May Warbler
Cape May Warblers were still common today, but not moving through in the numbers seen yesterday.
A male Black-throated Blue Warbler on Second Mountain.
A male Black-throated Blue Warbler.
Magnolia Warbler on Second Mountain.
Compared to yesterday’s flight, lesser numbers of Magnolia Warblers were seen today.
An adult male Wilson's Warbler on Second Mounatin.
An adult male Wilson’s Warbler was a good find among the hundreds of birds swarming the ridgetop.
Nashville Warbler
This Nashville Warbler spent much of the day in the tangles of Mile-a-minute Weed surrounding the lookout.

Other interesting Neotropical migrants joined the “waves” of warblers…

Red-eyed Vireo
Red-eyed Vireo numbers were higher than yesterday.
Warbling Vireo
This Warbling Vireo was found peering from the cover of the shady forest.
Rose-breasted Grosbeaks
A minimum of six Rose-breasted Grosbeaks were identified including the juvenile male seen here in first-fall plumage.  Other good sightings were Scarlet Tanagers, an adult male Baltimore Oriole, and a dozen or more Ruby-throated Hummingbirds.
Least Flycatcher on second Mountain.
Three Least Flycatchers were heard calling and seen chasing one another through a stand of dead timber on the south slope below the lookout.
Broad-winged Hawk
After the warbler flight settled, the task of counting migrating raptors commenced.  Five Broad-winged Hawks including this one were tallied as they glided away to the southwest for a winter vacation in the tropics of Central and South America.

Ruby-throated Hummingbirds on the Go

Ruby-throated Hummingbirds will be moving south through the Lower Susquehanna River Watershed during the next few weeks.
Ruby-throated Hummingbirds will be migrating south through the Lower Susquehanna River Watershed during the next few weeks.
Ruby-throated Hummingbird at Mexican Cigar.
While on their journey, they refuel by frequently visiting nectar-producing native wildflowers as well as garden specimens like this Mexican Cigar.
Ruby-throated Hummingbird at feeder.
Hummingbirds supplement their diet by visiting feeders filled with a mixture of sugar and water.  If you’re feeding hummingbirds, or thinking about feeding hummingbirds, be sure to review the helpful tips contained in our post from August 5, 2022, “Two Feeders Are Better Than One”.  Their health and your peace of mind may depend on it.