Brood XIV Periodical Cicadas in the Lower Susquehanna River Watershed

Here are some sights and sounds from the ongoing emergence of Brood XIV Periodical Cicadas in the Lower Susquehanna River Watershed.

We begin in the easternmost spur of the lower basin where a sizeable emergence of cicadas can be seen and heard in the woodlands surrounding the headwaters of the Conestoga River in Berks County north of Morgantown.  This flight extends east into Chester County and the French Creek drainage of the Schuylkill River watershed on State Game Lands 43 north of Elverson and consists of Pharaoh Periodical Cicadas (Magicicada septendecim), the most common species among 17-year broods.

Pharaoh Periodical Cicada
A Brood XIV Pharaoh Periodical Cicada at State Game Lands 43 identified by the red bar extending from the eye to the wing root.
Pharaoh Periodical Cicada
The underside of the abdomen on a male Pharaoh Periodical Cicada showing the wide orange bars on each segment.
Pharaoh Periodical Cicadas exuvia
Exuvia of a recently emerged Pharaoh Periodical Cicada.
Pharaoh Periodical Cicada singing
Soon after landing on a perch, a male Pharaoh Periodical Cicada will usually announce his presence by singing.  It’s an attempt to quickly attract potential mates that may be in the vicinity.
Pharaoh Periodical Cicadas
Pharaoh Periodical Cicadas ascending the branches of an oak.
Pharaoh Periodical Cicadas singing chorus
Gatherings of thousands of singing male Pharaoh Periodical Cicadas create a distinctive droning chorus.
Pharaoh Periodical Cicadas
A receptive female will make a click sound to summon a suitable singing male for mating.
Pharaoh Periodical Cicadas
While usually occurring in the safety of the trees, the breeding frenzy can spill over onto the ground where we happened to find this copulating pair.
Chestnut Oak Hosting Cicadas
After mating, female cicadas make slits in the end twigs of selected trees into which they lay their eggs.  The process of egg-laying and larval emergence will usually wilt and kill end growth on the affected branches, causing little harm to healthy trees.  It’s similar to the trim you might give to a bonsai plant to keep it stout and sturdy.
Pharaoh Periodical Cicadas
How long do Periodical Cicadas live?  Well, by last week, we were already finding dead specimens by the thousands.  Most of them had already completed their breeding cycle and planted the seeds for a new generation of Brood XIV cicadas.
A deceased Pharaoh Periodical Cicada at the Fire Tower Parking Area at French Creek State Park.  This specimen and a chorus on the hill’s forested south slope were the northeastern-most evidence of Brood XIV Periodical Cicadas we could find for the population cluster in portions of Berks, Chester, and Lancaster Counties around Morgantown.
Second-year Mississippi Kite Feeding on Cicadas
The abundance of Pharaoh Periodical Cicadas on State Game Lands 43 in Chester County has attracted numerous raptors, particularly wandering one-year-old birds that aren’t quite mature enough to nest.  Among the sightings have been Red-tailed Hawks, Red-shouldered Hawks, Broad-winged Hawks, and at least three Mississippi Kites, a rarity on the Piedmont this far inland from the coastal plain.  (See the post from June 5, 2021, for details on the occurrence of Mississippi Kites in northernmost Delaware during the Brood X emergence.)

From Route 82 north of Elverson to the west through the forested areas along Route 10 north of Morgantown and the Pennsylvania Turnpike, we found an abundance of Cassin’s Periodical Cicadas (Magicicada cassini) calling among the Pharaohs.  This mix of Pharaoh and Cassin’s Periodical Cicadas extends west along the north side of the turnpike into Lancaster County and State Game Lands 52 on Black Creek north of Churchtown.

Cassin's Periodical Cicada
A Brood XIV Cassin’s Periodical Cicada at State Game Lands 52 is identified by the all-black margin between the eye and the wing root and…
Cassin's Periodical Cicada
…the black underside of the abdomen with no orange stripes.
Cassin's Periodical Cicadas singing chorus
To penetrate the sounds of the more common Pharaoh Periodical Cicadas, male Cassin’s Periodical Cicadas gather in large concentrations to generate a loud, oscillating chorus.  Its volume will usually exceed that of the Pharaohs singing in the vicinity.
Cassin's Periodical Cicadas
Mated Cassin’s Periodical Cicadas copulating at State Game Lands 52.
Cassin's Periodical Cicadas mating
The underside of copulating Cassin’s Periodical Cicadas.
Cassin's Periodical Cicadas mating
A pair of Cassin’s Periodical Cicadas at state Game Lands 52 in Lancaster County.

Further west in Cornwall, Lebanon County, a Brood XIV emergence can be found on similar forested terrain: the Triassic hills of the Newark Basin—rich in iron ore and renowned for furnace operations during the eighteenth and nineteenth centuries.  Pharaoh Periodical Cicadas were the only species heard among this population that extends from Route 72 east through the woodlands along Route 322 into the northern edge of State Game Lands 156 in Lancaster County.

On the west side of the Susquehanna, yet another isolated population of Brood XIV Periodical Cicadas can be found in Perry County, just south of Duncannon on State Game Lands 170 on the slopes of “Cove Mountain”, the canoe-shaped convergence of the western termini of Peters and Second Mountains.

Pharaoh Periodical Cicadas dominated this Perry County chorus,…

…but we did detect at least one Cassin’s Cicada trying to find a mate.

Cassin's Periodical Cicada
A solitary Cassin’s Periodical Cicada issues a lonely song of short buzzes and ticking notes.  Fragmented populations, especially those that are only able to fly and increase their distribution every 17 years, often have a challenging time expanding and reuniting their disjointed ranges.

Not to say they aren’t present, but we have yet to detect the rarest species, Magicicada septendecula, the “Little Seventeen-year Cicada”, among the various populations of Brood XIV Periodical Cicadas emerging in the lower Susquehanna valley.  For the coming two weeks or so until this brood is gone for another 17 years, the search continues.

For more on both annual and periodical cicada species in the Lower Susquehanna River Watershed, be sure to click the “Cicadas” tab at the top of this page!

Photo of the Day

Great Spangled Fritillary
Along a quiet forest road, a Great Spangled Fritillary visits Red Clover (Trifolium pratense) to feed on nectar.

Photo of the Day

Cedar Waxwing Feeding on Juneberries
One of dozens of Cedar Waxwings seen descending upon ripe juneberries in a mini grove consisting of either Smooth Shadbush (Amelanchier laevis) or the allied and very similar-looking hybrid juneberry Amelanchier x lamarkii.  Smooth Shadbush can be grown as a shrub or small tree and is also known as Smooth Serviceberry, Allegheny Serviceberry, or Smooth Juneberry.  The hybrid Amelanchier x lamarkii is believed to be a naturally occurring cross between Smooth Shadbush (A. laevis) and either Canadian Serviceberry (A. canadensis) or Downy Serviceberry (A. arborea).  Juneberries/serviceberries/shadbushes, including a number of man-made cultivars, produce white flowers in early spring and can be obtained through numerous suppliers for inclusion in conservation projects, home gardens, or for use as street trees.  Believe it or not, the very productive planting seen here was located in a parking lot island at a busy Walmart store.

Beechnuts in a Jam

Renowned for its smooth, light-gray bark and its large size, the American Beech is one the most easily recognized trees found in climax forests throughout the lower Susquehanna valley.  Preferring rich soils, this shade tolerant native produces an abundance of nutritious nuts for wildlife including deer, turkey, grouse, squirrels, woodpeckers, and a variety of songbirds.

If you’ve visited a stand of beech trees lately, you may have noticed that the canopy seems a little sparse in comparison to the foliage of the oaks, poplars, and other hardwood species in the vicinity.

American Beech Canopy
Sunlight reaching the forest floor through gaps in the canopy of American Beech trees.

A closer look reveals the cause.  And yes, it’s big, big trouble.

American Beech with Beech Leaf Disease
Many newly emerged leaves on this American Beech are thickened and curling in comparison to apparently healthy leaves on the same branch.  These sickly leaves are being afflicted by Beech Leaf Disease (BLD), the result of infection by a parasitic roundworm, Litylenchus crenatae mccannii, a microscopic nematode that reaches its greatest abundance within the victim’s new buds.  After increasing their population density there during the summer and fall, the nematodes overwinter within the dormant buds, then cause progressive cell damage in the foliage that emerges during the spring to make the leaves appear “striped” before withering and falling away.
American Beech with Beech Leaf Disease
Early season leaves on an American Beech perishing from infection by Litylenchus crenatae mccannii, the nematode responsible for Beech Leaf Disease.  BLD also affects Oriental Beech (Fagus orientalis) and European Beech (F. sylvatica), both imported to North America for ornamental cultivation.  BLD was first detected Lake County, Ohio, during 2012 and has already spread to every county in Pennsylvania and into much of the northeastern United States and neighboring portions of Canada.  The nematode responsible for BLD possibly originated among F. orientalis stocks in Japan, but its exact origins remain unconfirmed.
Beech Infected by Litylenchus crenatae mccannii
Cell damage from Litylenchus crenatae mccannii makes the new foliage on this American Beech appear “striped” before total deterioration.
Stand of American Beech with BLD
A sparse canopy in a stand of native American Beech trees being destroyed by the nematode, Litylenchus crenatae mccannii.  Defoliation over a period of 5 to 8 years will probably prove fatal to trees of this size.  Smaller trees may succumb in just 2 to 4 years.  Other sources of stress such as the extended period of drought we recently experienced may hasten the demise of afflicted trees.

While treatment for BLD is possible, it must be done early.  Protecting an entire stand in a forest can be prohibitively expensive, but if you have a specimen tree or small grove you think you might like to save, click here for a Penn State Extension guide with more information.

Late May Action in the Forest

Here’s a short preview of some of the finds you can expect during an outing in the Lower Susquehanna River Watershed’s forests this week…

Mountain Laurel
The Mountain Laurel, designated as Pennsylvania’s state flower, is now in bloom.
Mountain Laurel Flower Buds
The buds of the Mountain Laurel remind us of a sugary frosting freshly squeezed from a baker’s pastry bag.
Mountain Laurel Flowers
The flowers of the Mountain Laurel, an evergreen understory shrub, invite pollinators to stop by for a sweet treat.
Little Wood-Satyr
Little Wood-Satyrs (Megisto cymela) are patrolling forest edges looking for mates and, to host their eggs and larvae, the stands of grasses they find most suitable.
Zabulon Skipper
Many of the species of small butterflies we call skippers are now active. The Zabulon Skipper can be found patrolling grassy forest edges, particularly near streams, ponds, and wetlands.
Red-spotted Purple
Among the showiest of our butterflies, the Red-spotted Purple (Limenitis arthemis astyanax) is seen here on the leaves of a Black Cherry, its favored host plant.
Red-spotted Purple
Another red-spotted Purple seen picking up minerals from a dried up puddle depression on a gravel road.
Susquehanna Riverlands State Park
Butterfly observers will do well to pay a visit to the new Susquehanna Riverlands State Park on Furnace Road north of Hellam in York County, Pennsylvania.
Trail to Schull's Rock Overlook
Upon arrival at Susquehanna Riverlands, drive back the gravel road for about a mile to the parking area at the edge of the agricultural field.  Then, hike the trail through the woods and farm hedgerow to the Schull’s Rock overlook on the river.  In the forests along this route, the understory is dominated by colonial stands of Common Pawpaw trees.
Common Pawpaw
Along the lookout trail to Schull’s Rock, the Common Pawpaws’ large leaves help them to shade out potentially fast-growing competition.  In proper growing situations, pawpaws develop clonal suckers that mature over time to create colonial stands of a single genetic plant.
Common Pawpaw understory.
A Common Pawpaw understory along the approach to Schull’s Rock.
Common Pawpaw
A colonial stand of Common Pawpaw along the trail leading to Schull’s Rock.
Zebra Swallowtail
During our recent visit to Schull’s Rock, dozens of Zebra Swallowtails were seen along the trail, many in the vicinity of their sole host plant, the Common Pawpaw.  But even more were observed along the edges of the fields and woods where nectar sources like this Multiflora Rose were being visited by numbers of butterflies we normally see only among abundant species like Cabbage Whites.  Absolutely amazing!
Scull's Rock Overlook
And the view of the Susquehanna and the Shock’s Mills railroad bridge at the mouth of Codorus Creek is pretty good too!
Common Pawpaw and Hooded Warbler
You can look for colonial stands of Common Pawpaw at other parks and preserves along the lower Susquehanna as well.  Birds like this Hooded Warbler can sometimes be found among them in mature riparian forests along the steep slopes of the river gorge.
Common Pawpaw and Baltimore Oriole
A Baltimore Oriole in a Common Pawpaw along a forest edge.
Blackpoll Warbler
Meanwhile in the treetops, the spring thrust of Neotropical migrants is drawing to a close.  The Blackpoll Warbler is typically one of the last to transit the lower Susquehanna valley on its way to northern coniferous forests for summer.  They’ve had an unusually protracted movement through the region this spring, the earliest individuals reported during late April.  Though very difficult to see in the canopy of the mature trees where it feeds and sings, hearing one is often a benchmark for senior birders each spring.  Older observers have often said of the Blackpoll Warbler’s high-pitched song, a rapid series of insect-like staccato “tseet” notes, that it was the first they could no longer detect as their ears started losing sensitivity.
American Redstart
In many tracts along the lower Susquehanna this spring, the American Redstart is turning out to be the most common nesting warbler.  Conditions favoring their reproductive success in recent cycles, as well as good survival rates during their migrations and stays on wintering grounds, have filled many lowland forests with redstart songs in 2025.  Is this the start of a trend or just an exceptionally good year?  Time will tell.
Rose-breasted Grosbeak
Yet one more reason for a stroll in local forests this week is the chance to see and hear the Rose-breasted Grosbeak.  Look for these Neotropical relatives of the cardinal nesting on territories in mature stands of deciduous trees like this Yellow Poplar, a species also known as the Tuliptree.
They spend nearly all their time among the canopy foliage of the largest timber…
Rose-breasted Grosbeak
…but pause frequently to repeat a song often described as something akin to that which might be performed by a robin subjected to voice lessons.  The Rose-breasted Grosbeak is certainly a bird worth seeing and hearing.

Five Flowering Plants for Cleaner Water

Currently in the Lower Susquehanna River Watershed, you can find these five species of herbaceous plants in full bloom.  As they grow, they and others like them help to purify waters within their respective ecosystems by taking up nutrients—namely, the nitrogen and phosphorus that can lead to detrimental algal blooms and eutrophication in ponds, lakes, streams, and rivers.

(United States Geological Survey image by Virginia-West Virginia Science Center)
Marsh Blue Violet
The Marsh Blue Violet (Viola cucullata) is most frequently found growing in the wet soils of forest bottomlands, usually where springs first break the earth’s surface and begin slowly trickling away to form a small brook or join an existing stream.  The blooms are recognized by their darker purple centers and their long stems.
Marsh Blue Violet
This particular Marsh Blue Violet was found at 750′ altitude in the running water at a mountainside spring seep on a south-facing slope in the Ridge and Valley Province.
Soft Rush
The seldom-noticed flowers of the Soft Rush (Juncus effusus), also known as the Common Rush, emerge from the sides of its quill-like stems.  This wetland species is found in damp soils, sometimes in standing water, and grows in stiff, erect clumps that persist through winter.  When found in pastures, Soft Rush is seldom of interest to cattle or other livestock.  It therefore doesn’t lure these animals into muddy, puddle-prone areas.  When subjected to heavy grazing in dry weather and flooding during wet spells, these puddle sites may host nearly pure stands of Soft Rush, the only plant able to thrive there.  When it comes to nutrient uptake in these soggy sections of the meadow, the soft Rush is the lone ranger.  Soft Rush seeds are available from Ernst Conservation Seeds in Meadville, PA, and are included in many of their mixes formulated for stormwater management basins and other wet soil applications.
Larger Blue Flag
Larger Blue Flag (Iris versicolor) is a plant of wetlands and shorelines.  It can be grown as an emergent in ponds and lakes where it will help to absorb nutrients from both the water and the underlying substrate.
Larger Blue Flag
Larger Blue Flag is a native species in the lower Susquehanna valley.
Yellow Iris
The Yellow Iris (Iris pseudacorus), also known as the Water Flag, is native to Eurasia and Africa.  Seen here growing as an emergent among native Common Cattails (a superb water purifier), the Yellow Iris can easily escape cultivation and become invasive.  The showy flowers and water-cleansing benefits of this plant make it attractive for use in the garden or farm pond, but considerations must be made for its aggressive growth and proclivity to escape to neighboring habitats.  If you’re purchasing irises for transplanting, you’re probably better off sticking with the native Larger Blue Flag; it is far less vigorous and you’ll be able to grow other aquatic species along with it.
Spatterdock
In large ponds, lakes, and low-gradient streams, one of the best aquatic plants for sequestering nutrients and clarifying water is Spatterdock, also known as Cow-lily or Yellow Pond Lily.  Spatterdock does best as an emergent in shallow water along the shoreline.  It grows well in full sunshine and makes excellent habitat for wildlife.  Depending on the nutrient load from fish, waterfowl, decaying vegetation, and other sources, plant cover may need to be as high as 30% or more of the surface area to keep algae from overtaking a lake or large pond.  Spatterdock can often be used to help fulfill these needs while still offering open water beneath the leaves and between the stems for fish, amphibians, reptiles, and macroinvertebrates to thrive.
Spatterdock
Though probably not suitable for small garden ponds, Spatterdock (Nuphar advena) can be an excellent choice for helping to clear up the nutrient-loaded waters of a farm pond or lake.  You can find it, the irises, and Soft Rush available through some pond nurseries and garden centers.  If you can’t get them locally, check out retail and wholesale suppliers online, but remember to inspect any livestock you bring in from outside the area for hitchhikers like non-native snails (native snails are O.K.).  To be safe, always quarantine and monitor your aquatic plants for 30 days.  Tubers can be given a bath in 3% hydrogen peroxide solution for up to five minutes, then rinsed with water.  Repeat the treatment as needed until no snails or eggs are seen.  Another option: local pond owners who have them may be willing to divide some Iris and/or Spatterdock tubers and provide them for sale or gift to those who ask.  Just a couple will get you started.

Their Songs Give Them Away

After repeatedly hearing the songs of these Neotropical migrants from among the foliage, we were finally able to get a look at them—but it required persistent effort.

Magnolia Warbler
Often found closer to the ground among shrubs and small trees, this Magnolia Warbler was a challenge to find in the upper reaches of a Chestnut Oak.
Yellow-rumped Warbler
Not far away, we spied this Yellow-rumped Warbler.
Red-eyed Vireo
Despite its status as probably the most common Neotropical songbird to nest in the deciduous woodlands of the lower Susquehanna valley, the Red-eyed Vireo is nevertheless notoriously difficult to locate among the leaves.
Ovenbird
The Ovenbird spends much of its time on the forest floor where it builds a domed, oven-like nest.
Ovenbird
A fortunate observer may catch a glimpse of one perched in an understory shrub or small tree.
Ovenbird
But hearing the Ovenbird’s song, “teacher-teacher-teacher”, is frequently the only way to detect it.
Worm-eating Warbler
The Worm-eating Warbler nests in understory thickets on steep forested slopes.  Its rich chipping song is often the only indication of its presence.
American Redstart
Frequently easier to locate is the American Redstart, a Neotropical warbler that calls out its territory in damp woodlands from perches atop shrubs or among the lower limbs of trees.
Warbling Vireo
Warbling Vireos nest near streams or other bodies of water in large deciduous trees like this Northern Hackberry.
Gray Catbird
Gray Catbirds are abundant in shrubby gardens and thickets.  Most will come out of hiding to investigate disturbances like an observer making a pishing sound.
Common Yellowthroat
Another inhabitant of brushy successional growth is the Common Yellowthroat.  It too is curious and responds quickly to squeaky sounds made by human visitors to their home ground.
Yellow-breasted Chat
The Yellow-breasted Chat is a bird of early successional growth.  To establish and defend a breeding territory, this one adopted a perch along the edge of a woodlands overlooking a field in which prescribed fire was administered less than two months ago.
Yellow-breasted Chat
Like the mockingbird and thrasher, the Yellow-breasted Chat is a mimic.  Its song is a repertoire of the calls and songs of the bird species with which it may compete for food and nesting space.  Unique to the chat is an occasional pause, whistle, or “chuck” note that creates a bridge between many of its song’s elements.
Yellow-breasted Chat
The intensely territorial chat dropping down to look us over.

Sometimes we have to count ourselves lucky if we see just one in five, ten, or even twenty of the birds we hear in the cover of the forest canopy or thicket.  But that’s what makes this time of year so rewarding for the dedicated observer.  The more time you spend out there, the more you’ll eventually discover.  See you afield!

Scarlet Tanager
A singing Scarlet Tanager lurking in the shade of an oak.
Scarlet Tanager
Seeing is believing.

Six Flowering Woody Plants

Here’s a look at six native shrubs and trees you can find blooming along forest edges in the lower Susquehanna valley right now.

Black Locust
The Black Locust (Robinia pseudoacacia), a member of the pea or legume family (Fabaceae), can be a dominant pioneer plant of sunny successional habitats, particularly on poor soils.  Nodules along its roots fix nitrogen to help facilitate the growth of the intermediate and climax species of trees and shrubs that replace the pioneers.  Initially armed with protective spines to reduce browsing, the Black Locust’s branches become mostly thornless as the tree matures.
Pinxter Flower
The Pinxter Flower, also known as the Pink Azalea, is certainly a contender for our most spectacular native blossoming shrub;…
Spicebush Swallowtail on Pinxter Flower
…this Spicebush Swallowtail seems to like it too.
Black Cherry
When in bloom, the Black Cherry is a common sight in regional woodlands.  Often seen already covered with blossoms when young and shrub-like, many of these trees will continue flowering and producing fruit throughout the decades required to reach a mature height of 60 feet or more.
Blackhaw
The Blackhaw is an understory shrub preferential to sun-dappled areas beneath a break in the forest canopy.  Pollinated flowers later produce clusters of blue-black berries for birds and other wildlife.
Common Pawpaw
It’s easy to overlook the flowers of the Common Pawpaw.  By the time the leaves are fully emerged and casting shade, blooming time is over.
Flowering Dogwood
Nowadays, the Flowering Dogwood is most frequently encountered as a transplanted cultivar in city and suburban landscapes.  In the wild, it is sparingly distributed throughout the region’s deciduous forests.  These slow-growing little trees produce bright red berries that are quickly seized by a variety of birds upon ripening in the fall.

Local old timers might remember hearing folklore that equates the northward advance of the blooming of the Flowering Dogwoods with the progress of the American Shad’s spring spawning run up the river.  While this is hardly a scientific proclamation, it is likely predicated on what had been some rather consistent observation prior to the construction of the lower Susquehanna’s hydroelectric dams.  In fact, we’ve found it to be a useful way to remind us that it’s time for a trip to the river shoreline below Conowingo Dam to witness signs of the spring fish migration each year.  We’re headed that way now and will summarize our sightings for you in days to come.

Flowering Dogwood
Tree blossoms open in response to the presence of adequate moisture and exposure to the warming effects of sunshine.  Shad ascend the Susquehanna to spawn in response to suitable river flow and increasing water temperature.  Sun and rain in the appropriate proportions can often conspire to synchronize otherwise unrelated events.  Hence, a Flowering Dogwood in bloom along the edge of a mature forest means it’s time to go check out the shad run.

Fresh Foliage and Plumes

Despite what seemed to be a chilly early spring, the bright green leaves that unfold to close the canopy of our deciduous forests were dense and casting shade by the last days of April.  For northbound migrants, this fresh foliage provides the cover they need for foraging, resting, and, for those that will stick around to breed in the lower Susquehanna valley, nesting.

We recall many occasions when sparse foliage during the first days of May seemed to delay the big push of Neotropical species, but the seasonal arrival of these birds in 2025 is thus far mostly ahead of schedule.  This absence of delay is due in part to the lushness of the oaks.  Some stands have not only leafed out, but are finished flowering and have added up to 12 inches of new branch growth.  We spent these early hours of May among the oaks.  Here’s a look at the Neotropical migrants and other species we found…

Cape May Warbler
Dozens of species of Neotropical warblers have arrived in the Lower Susquehanna River Watershed.  Some will nest locally while others will continue along flight paths that will ultimately take them far to our north.  We spotted this Cape May Warbler in the upper reaches of a Northern Red Oak feeding among its spent flowers.  Its destination: the spruce forests of northern New England and Canada.
Yellow-throated Vireo
Slightly larger than the warblers are the vireos, including this Yellow-throated Vireo that has arrived to nest in an oak-maple bottomland.
Baltimore Oriole
Always a fan favorite, we found this marvelously tropical Baltimore Oriole among the foliage of a flowering White Oak.
Red-tailed Hawk
This young Red-tailed Hawk has survived its first winter.  It appears to have learned from experience how to hunt from advantageous locations such as this Chestnut Oak along a utility right-of-way where prey may include numerous squirrels as well as mice and other small mammals.
American Kestrel
We were taking a break beneath this Pin Oak when suddenly an American Kestrel arrived to begin scolding a trespasser that was straying a bit too close to its nest;…
Northern Harrier
…the intruder, a Northern Harrier, soon took the hint and continued on its way.
Veery
While among the oaks, it pays to check the understory where Neotropical thrushes including the Veery are arriving to fill the forests with their melodious songs.
White-throated Sparrow
Following their nocturnal flights, the last of the season’s northbound White-throated Sparrows may presently be found spending the day in the cover of the oak woodland understory.

The movements of our migratory birds typically continue through much of the month of May.  And peak numbers of Neotropical species often occur sometime during the second week of the month.  But with habitat at the ready, favorable flight conditions could facilitate quick arrival and/or passage of the bulk of the remaining migrants during the coming week.  You may want to venture out sooner rather than later—but watch your step!

Mayapple
The Mayapple, a native wildflower also known as the Mandrake, is now in bloom among the oak leaf litter.
Canada Mayflower
And the Canada Mayflower (Maianthemum canadense), a native species also known as Wild Lily-of-the-valley, is blooming in moist mixed-oak forests.
White-crowned Sparrow
At the edge of an oak-maple woodland, we found this lingering White-crowned Sparrow foraging among the leaf litter and fresh, shiny foliage of Poison Ivy.  Songbirds can spend their days scratching the ground among these leaves of three.  If you do it, you’ll be scratching something else, and you may need an ocean of calamine lotion to boot!

Photo of the Day

Juvenile Eastern Cottontail
This petite Eastern Cottontail somehow found a path through weekend traffic to discover an abundant supply of lush green Indian Strawberry (Potentilla indica) leaves in the garden at susquehannawildlife.net headquarters.  The widely naturalized Indian Strawberry, also known as Mock Strawberry, is native to Asia.  It is most easily recognized by its bright yellow flowers which soon yield edible, but not very tasty, little red fruits.  I wonder, might the berries be more palatable if dipped in a melted-down chocolate bunny?  Food for thought, unless of course you have an aversion to hare in your romantic confections.

Early Season Wildflowers

Here are five common forest flowers that the average visitor to these environs may easily overlook during an early April visit.

Skunk Cabbage
The flowers of the Skunk Cabbage, a native member of the arum family, are contained within a spadix which is partially hidden inside the mottled maroon spathe at the base of the plant.  In late winter, the closed spathe generates its own heat to melt through frozen water and soils to make its appearance in streamside and spring-fed wooded wetlands, just ahead of the emergence of the large green leaves.
Common Spicebush
Common Spicebush is a native flowering shrub of damp woodland understories.  Later in the season, its foliage provides food for Spicebush Swallowtail caterpillars.  Pollinated blossoms yield bright-red oblong berries relished by a variety of birds in fall and winter.
Red Maple
The flowers of the indigenous Red Maple will soon generate the familiar helicopter-like winged seeds which readily distribute this native tree into new ground ranging from lowlands to the crests of our highest ridges.
Coltsfoot
Coltsfoot (Tussilago farfara) is non-native wildflower of Eurasian origin.  Reminding one at first glance of a dandelion, it is commonly seen blooming in disturbed areas of woodlands.  Coltsfoot often grows where it has little competition from other plants, such as among the debris left behind due to snow plowing and grading along forest roads.
Sweet Cherry
Though not particularly abundant, the non-native Sweet Cherry, an escape from cultivation, is widespread in forests and woodlots throughout the lower Susquehanna valley.  Sweet Cherry is believed to be an ancestor of the Sour Cherry (Prunus cerasus) and is frequently used as rootstock for orchard and garden varieties of this popular fruit.  Sweet Cherry is often called “Wild Cherry”, a name also applied to the Black Cherry, a native tree which blooms later in the spring.

Be certain to get out and enjoy this year’s blooming seasons of our hundreds of varieties of flowering plants.  But, particularly when it comes to native species,…

Early-spring Maples: Clouds of Color Across the Forest Canopy

By late winter, sunshine and warming temperatures awaken the sleeping maples of the lower Susquehanna basin and the sap begins to flow.  The new growing season is evident by the first days of spring when their swelling buds and flowers paint the drab gray canopy of deciduous woodlands with an overlying coat of red, orange, and maroon.

Red Maples in Early Spring
Red Maples, renowned for their vibrant autumn foliage, are just as conspicuous in the early spring landscape.
Eastern Gray Squirrel Feeding on Red Maple Buds
For birds and mammals like this Eastern Gray Squirrel, the buds and flowers of maples mean relief from the diminished natural food supplies that helped them survive winter’s worst.  The season of abundance has arrived and these animals instantly recognize this source of sweet, fresh energy, just in time for the breeding season.  The flowers of maples, which later in the spring yield those familiar helicopter-like seeds, are an important early season source of energy for many species of bees and other pollinators.

Think Spring: Order Your Seedlings Now!

Our wildlife has been having a tough winter.  The local species not only contend with cold and stormy weather, but they also need to find food and shelter in a landscape that we’ve rendered sterile of these essentials throughout much of the lower Susquehanna valley’s farmlands, suburbs, and cities.

Planting trees, shrubs, flowers, and grasses that benefit our animals can go a long way, often turning a ho-hum parcel of property into a privately owned oasis.  Providing places for wildlife to feed, rest, and raise their young can help assure the survival of many of our indigenous species.  With a little dedication, you can be liberated from the chore of manicuring a lawn and instead spend your time enjoying the birds, mammals, insects, and other creatures that will visit your custom-made habitat.

Verdant Neighborhood
What makes some neighborhoods so appealing?  It’s the foresight property owners had a half a century or more ago when they planted their lawns and gardens with a variety of sturdy, long-lived trees and shrubs.  They’ve not only minimized the need for mowing grass, they’ve provided the present-day residents of their home with added thermal stability during both the blazing heat of summer and the chilling cold of winter.

Fortunately for us, our local county conservation districts are again conducting springtime tree sales offering a variety of native and beneficial cultivated plants at discount prices.  Listed here are links to information on how to pre-order your plants for pickup in April.  Click away to check out the species each county is offering in 2025!

Cumberland County Conservation District Annual Tree Seedling Sale—

Orders due by: Friday, March 21, 2025

Pickup on: Thursday, April 24, 2025 or Friday, April 25, 2025

Zebra Swallowtail on Wildflowers
During its 2025 tree seedling sale, the Cumberland County Conservation District is offering Northeast Native Wildflower seed mix for four dollars per ounce.  One ounce plants approximately 200 square feet of bare soil.  This is a Zebra Swallowtail visiting nectar-rich flowers during July of the first year after sowing this mix at a site along the Susquehanna.

Dauphin County Conservation District Seedling Sale—

Orders due by: Monday, March 17, 2025

Pickup on: Thursday, April 24, 2025 or Friday, April 25, 2025

"Red-twig Dogwood"
Able to thrive in wet soils, Red-osier and Silky Dogwood shrubs are ideal plants for intercepting and polishing stormwater in swales, detention/retention basins, and rain gardens.  With their crimson twigs in winter, they look great along borders among clusters of cedars, pines, spruces, and other evergreens.  They make an excellent choice for soil stabilization along the shorelines of streams, ponds, and other bodies of water too.  Buy a dozen or more to create a showy mass planting in your soggy spot.

Franklin County Conservation District Tree Seedling Sale—

Orders due by: Wednesday, March 19, 2025

Pickup on: Thursday, April 24, 2025

American Elm
The Franklin County Conservation District is offering American Elm seedlings in bundles of 25 for 36 dollars.  Start them in pots for a couple of years to really get ’em going, then find places with damp soil and plenty of room to give ’em a try.  During autumn, they look great in the company of spruces, white pines, and other large evergreens.

Lancaster County Annual Tree Seedling Sale—

Orders due by: Friday, March 7, 2025

Pickup on: Friday, April 11, 2025

Norway Spruce and White Pine
We purchased these Eastern White Pine, Norway Spruce, and Common Winterberry plants from the Lancaster County Conservation District Tree Sale about four years ago.  They’re filling in as understory growth in the margins beneath some thirty-year-old Eastern Hemlocks to create dense cover for resident and visiting fauna at susquehannawildlife.net headquarters.

Lebanon County Conservation District Tree and Plant Sale—

Orders due by: Monday, March 3, 2025

Pickup on: Friday, April 18, 2025

For 2025, the Lebanon County Conservation District is offering Dawn Redwood (Metasequoia glyptostroboides) trees in packs of ten for twelve dollars.  Though native to Asia, these adaptable trees present little threat of naturalizing and have many positive attributes in a conservation planting.  Given ample space, the Dawn Redwood, a relative of the sequoias, will rapidly grow to a towering giant.  They create a particularly dramatic landscape feature when planted in clumps of three to five trees or more.  With age, the trunks become stout and very sturdy.  Don’t like raking?  The finely divided deciduous foliage can be left where it falls in autumn.  It usually disintegrates by spring to enrich the soil and promote more growth.
The genus Metasequoia was first described in 1941 based upon fossils collected in Jurassic and earlier strata from widespread locations in the northern hemisphere. Metasequoia were believed extinct until just a few years later when a small number of living Dawn Redwoods were first discovered in southern China.  Now distributed around the world for cultivation, direct descendants of this wild population of Metasequoia glyptostroboides are available for nearly anyone in a temperate climate to plant and grow to exceptional size.  (National Park Service image)
Bald Cypress
The Lebanon County Conservation District is also selling Bald Cypress trees.  They’re offered in bundles of ten for ten dollars.  These long-lived trees resemble the Dawn Redwood.  Both are tolerant of damp ground, but the native Bald Cypress is the species to choose for placement along streams, in wetlands, and on other sites with standing water or saturated soil.
Wildlife rich Bald Cypress swamps currently occur on the Atlantic Coastal Plain as far north as Sussex County, Delaware.  Just to the south, they’re also found along Chesapeake Bay in areas that, during the last glacial maximum when sea level was 300 to 400 feet below today’s tide lines, were the Lower Susquehanna River Watershed in portions of present-day Maryland and Virginia.  The northward post-glacial range extension of Bald Cypresses is now blocked by centuries of human intervention that has eliminated, isolated, or fragmented the wetland habitats where they could potentially become established.  Why not lend them a hand?  Plant a cypress swamp in your flood-prone bottomland.  (National Park Service image by Andrew Bennett)

York County Conservation District Seedling Sale—

Orders due by: March 15, 2025

Pickup on: Thursday, April 10, 2025

White Pines and Northern Red Oaks
A privacy planting of sturdy, native Eastern White Pines and Northern Red Oaks thriving around the border of a parking area where they also provide shade from the sun and help infiltrate a share of the stormwater that would otherwise become runoff.
Native Northeast Wildflower and Grass mix during its first summer
This year, the York County Conservation District is offering a Showy Northeast Native Wildflower and Grass seed mix for $19.99 per quarter pound.  Sure beats mowing!

If you live in Adams County, Pennsylvania, you may be eligible to receive free trees and shrubs for your property from the Adams County Planting Partnership (Adams County Conservation District and the Watershed Alliance of Adams County).  These trees are provided by the Chesapeake Bay Foundation’s Keystone 10-Million Trees Partnership which aims to close a seven-year project in 2025 by realizing the goal of planting 10 million trees to protect streams by stabilizing soils, taking up nutrients, reducing stormwater runoff, and providing shade.  If you own property located outside of Adams County, but still within the Chesapeake Bay Watershed (which includes all of the Susquehanna, Juniata, and Potomac River drainages), you still may have an opportunity to get involved.  Contact your local county conservation district office or watershed organization for information.

Planted Riparian Buffer
As they mature, tree and shrub plantings along streams return pollution-controlling functions to floodplains and provide critical habitat for wildlife.  These riparian buffers not only improve water quality for fisheries, they also create travel corridors that prevent terrestrial animal populations from becoming isolated.
A CREP Project Area
Do you own a parcel of streamside or wetland acreage that you’d like to set aside and plant for the benefit of wildlife and water quality?  Contact your local county conservation district office and ask them to tell you about CREP (Conservation Reserve Enhancement Program) and other programs that may offer incentives including payment of all or a portion of the costs of plantings and other habitat improvements.

We hope you’re already shopping.  Need help making your selections?  Click on the “Trees, Shrubs, and Woody Vines” tab at the top of this page to check out Uncle Tyler Dyer’s leaf collection.  He has most of the species labelled with their National Wetland Plant List Indicator Rating.  You can consult these ratings to help find species suited to the soil moisture on your planting site(s).  For example: if your site has sloped upland ground and/or the soils sometimes dry out in summer, select plants with a rating such as UPL or FACU.  If your planting in soils that remain moist or wet, select plants with the OBL or FACW rating.  Plants rated FAC are generally adaptable and can usually go either way, but may not thrive or survive under stressful conditions in extremely wet or dry soils.

NATIONAL WETLAND PLANT LIST INDICATOR RATING DEFINITIONS

      • OBL (Obligate Wetland Plants)—Almost always occur in wetlands.
      • FACW (Facultative Wetland Plants)—Usually occur in wetlands, but may occur in non-wetlands.
      • FAC (Facultative Wetland Plants)—Occur in wetlands and non-wetlands.
      • FACU (Facultative Upland Plants)—Usually occur in non-wetlands, but may occur in wetlands.
      • UPL (Upland Plants)—Almost never occur in wetlands.

Using these ratings, you might choose to plant Pin Oaks (FACW) and Swamp White Oaks (FACW) in your riparian buffer along a stream; Northern Red Oaks (FACU) and White Oaks (FACU) in the lawn or along the street, driveway, or parking area; and Chestnut Oaks (UPL) on your really dry hillside with shallow soil.  Give it a try.

Photo of the Day

Red-bellied Woodpecker
You may be on the verge of satisfying your appetite with chestnuts from an open fire, but this Red-bellied Woodpecker is just as pleased to retrieve a Shagbark Hickory nut from a hiding place among the tree’s cracks and crevices where it was stashed away earlier in the fall.

Five Favorite Visitors from the Northern Forests

As the autumn bird migration draws to a close for 2024, we’re delighted to be finding five of our favorite visitors from the coniferous and mixed forests of Canada and the northernmost continental United States.

Male Yellow-bellied Sapsucker
Yellow-bellied Sapsuckers drill evenly spaced holes which they repeatedly visit to harvest “sap” and the insects that become trapped therein.  These surgically small excavations penetrate only the bark and the phloem, a shallow, spongy layer of the trunk that carries sugars from the leaves to other parts of the tree.  Seldom do they puncture the thin, underlying cambium layer which protects the true sapwood.  After healing, sapsucker holes leave linear rows of small scars which are sometimes still discernible decades after a bird’s final visit.  This adult male will probably linger in the Lower Susquehanna River Watershed until colder weather renders the tree totally dormant, the flow of “sap” ebbs, and small insects become harder to find.  Then he’ll make his way off toward southern forests of oak and pine for the remainder of the winter.  Sapsuckers work their way north as sugary “sap” begins flowing again in the spring.
Hermit Thrush
The Hermit Thrush is another denizen of coniferous and mixed forests.  In habitats with dense cover and sufficient food sources like fruit-bearing shrubs and vines, some will remain through the winter.  The Hermit Thrush is the only spot-breasted thrush regularly seen in our region from November through March.
Fox Sparrow
Almost the size of a thrush, the largest of our native sparrows, the Fox Sparrow, is currently at the peak of its southbound migration.  While taking a break from their nocturnal flights, some may stray from forest edges to visit suburban feeding stations.  Most leave our area by mid-December, then begin returning north as early as mid-February.
Pine Siskins
Not present every year, flocks of Pine Siskins are beginning to arrive in the lower Susquehanna region.  They are currently most common along the mountain tops of the Ridge and Valley Province where they are feeding on the seeds of the Sweet Birch, a tree also known as Black Birch.  Look for them around niger seed feeders and on the prickly seed balls of cultivated American Sweetgum, but don’t be surprised if they quickly pass us by to spend the winter on the Atlantic Coastal Plain to our south where this native tree grows in abundance.
Female/Juvenile Male Purple Finch
Since late October, Purple Finches have been widespread throughout the region.  These female/juvenile male types are frequently being seen at feeders, particularly near woodlands and other areas with stands of conifers.
Male Purple Finch
Less frequently seen are the adult male Purple Finches in their raspberry-colored plumage.  What a dandy.

While right now is the best time to get out and look for these species from the northern forests, any or all of them could linger into the winter months, particularly where the food supply is sufficient and conifers and other evergreens provide cover from the blustery weather.

A Towering American Elm

During the past week, Uncle Tyler Dyer has been out searching for autumn leaves to add to his collection.  One of the species he had not encountered in previous outings was the American Elm (Ulmus americana), so he made a special trip to see a rare mammoth specimen in a small neighborhood park (Park Place) along Chestnut Street between 5th and Quince Streets in Lebanon, Pennsylvania.

American Elm at Park Place in Lebanon, Pennsylvania
Possibly the largest and oldest remaining American Elm in the lower Susquehanna watershed, the Park Place tree in Lebanon exceeds 60 feet in height and may be more than 300 years of age.  In the nearly one hundred years since Dutch elm disease (DED) first began killing elms in eastern North America, this tree has been spared the fatal effects of the infection.  DED is caused by several species of microfungi (Ophiostoma ulmi, O. himal-ulmi, and O. novo-ulmi) spread by numerous bark beetle (Curculionidae) species.  As early as 1928, infected beetles arrived in the United States from the Netherlands among shipments of logs.
Leaves of the American Elm.
Leaves of the American Elm.

There’s still time to get out and see autumn foliage.  With warmer weather upon us—at least temporarily—it’s a good time to go for a stroll.  Who knows, you might find some spectacular leaves like these collected by Uncle Ty earlier this week.  All were found adorning native plants!

Winged Sumac
Winged Sumac (Rhus copallina), a small native tree.  In case you’re wondering, it’s not poisonous.
Black Chokeberry
Black Chokeberry (Photinia melanocarpa), a native shrub also known as Aronia.  It produces black-colored fruits in summer.
Red-osier Dogwood
Red-osier Dogwood (Cornus sericea), a shrub that prefers wet or damp soils.  It yields white fruits.
Maple-leafed Viburnum
Maple-leafed Viburnum (Viburnum acerifolium), a native shrub of upland forest understories.
Highbush Blueberry
Highbush Blueberry (Vaccinium corymbosum), a native shrub and the source of many cultivated forms of the popular fruit.
To identify your finds, be certain to click the “Trees, Shrubs, and Woody Vines” tab at the top of this page to check out Uncle Ty’s extensive collection.

Things to See While You’re Leaf Peeping

During your foray to view the colorful foliage of the autumn landscape, a little effort will reveal much more than meets the eye of the casual observer.

Fallen Foliage in the Forest
Don’t just stand there like a bump on a log, go for a stroll, watch your step, and have a look around.  There’s a lot to see out there!
Witch-hazel
The dense understory of this forest on Blue Mountain consists almost exclusively of Witch-hazel (Hamamelis virginiana).
Witch-hazel in Flower
Witch-hazel is unique among our native flowering shrubs; it blooms in autumn.
Common Buckeye
Until we experience a heavy frost, some of our most beautiful butterflies, including this Common Buckeye, remain active along forest edges.
An Eastern Tailed Blue
An Eastern Tailed Blue.
A Pearl Crescent.
A Pearl Crescent.
A Variegated Fritillary.
A Variegated Fritillary.
Painted Lady.
A Painted Lady.
Yellow-rumped Warbler
The arrival of large numbers of Yellow-rumped Warblers heralds the transition to movements of migrants that will spend the colder months in temperate climates like ours instead of continuing on to the tropics.  In winter, small numbers of “yellow-rumps” sometimes linger in the Lower Susquehanna River Watershed, as long as a supply of wild berries is readily available.
Palm Warbler
The Palm Warbler, a persistent “tail wagger”, is another late-season migrant that occasionally spends the winter.  The migration of these drab “Western Palm Warblers” will be followed in coming weeks by the more yellowish “Eastern Palm Warblers” of the eastern third of the species’ breeding range in Canada.
White-throated Sparrow
White-throated Sparrows are southbound and easily observed right now.  Many will remain along our brushy forest edges for winter.
Dark-eyed Junco
Another native sparrow, the familiar Dark-eyed Junco, is now arriving.
Yellow-bellied Sapsuckers
The Yellow-bellied Sapsucker is a secretive migratory woodpecker that is currently moving through the region on its way to southern pine forests for the winter.  Juveniles like this one in the lower right remain close to their parents during migration and continue to beg for food.
Pileated Woodpecker
The Pileated Woodpecker is a resident species in our mature forests and woodlands.  We were showered by “sawdust” as we watched this one dismantling a rotted dead tree while searching for beetle grubs and other invertebrates.
Eastern Bluebird
You may see Eastern Bluebirds year-round in the lower Susquehanna valley, but many are migratory.  A southbound push is currently transiting our area.
Hawk Watching on Blue Mountain at Boyd Big Tree Preserve.
Mix your leaf watching with hawk watching by visiting a ridgetop vista like this one at Boyd Big Tree Preserve Conservation Area on Blue Mountain north of Harrisburg and you can double your pleasure.
Common Raven
In addition to spectacular foliage, you stand a good chance of seeing an inquisitive Common Raven…
Screaming Red-tailed Hawk
…or a migrating Red-tailed Hawk that gives you a good scream as it passes by…
Bald Eagle
…or a majestic Bald Eagle.
Common Ravens
You may even double your fun by seeing two Common Ravens…
Red-tailed Hawks
…or a couple of migrating Red-tailed Hawks…
Bald Eagles
…or a pair of Bald Eagles passing thru.

You too can experience the joys of walking and chewing gum at the same time, so grab your field glasses, your camera, and your jacket, then spend lots of time outdoors this fall.  You can see all of this and much more.

Don’t forget to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page to help you find a place to see both fall foliage and migrating birds of prey in coming weeks.  And click the “Trees, Shrubs, and Woody Vines” tab to find a photo guide that can help you identify the autumn leaves you encounter during your outings.

Photo of the Day

Ruby-throated Hummingbird
Here today, gone tomorrow.  This Ruby-throated Hummingbird lingered around the numerous tubular flowers in the headquarters garden until near darkness last evening.  It was last seen entering the cover provided by our Eastern Hemlocks where it presumably spent the night.  Bright and early this morning, it made repeated visits to Mexican Cigar and this Bat-faced Cuphea to re-energize before resuming its long voyage to the tropics for winter.  This marks the third consecutive year we’ve been visited by late-season hummingbirds during the first week of October.  All were attracted to our nectar-rich plantings.

This Week’s Review of the Morning Fallouts

Clear, cool nights have provided ideal flight conditions for nocturnal Neotropical migrants and other southbound birds throughout the week.  Fix yourself a drink and a little snack, then sit down and enjoy this set of photographs that includes just some of the species we found during sunrise feeding frenzies atop several of the Lower Susquehanna River Watershed’s ridges.  Hurry up, because here they come…

Black-throated Green Warbler
A Black-throated Green Warbler.
Black-throated Green Warbler
The Black-throated Green Warbler was perhaps the most frequently identified treetop warbler during the most recent four mornings.
Black-throated Green Warbler
A Black-throated Green Warbler with a unique variation in the crown plumage.
Blackburnian Warbler
The Blackburnian Warbler was another plentiful species.
Cape May Warblers
Cape May Warblers have an affinity for conifers like this Eastern White Pine.
Cape May Warbler
But when traveling in mixed flocks with other migrants, Cape May Warblers can also be found feeding in the crown foliage of deciduous trees.
Tennessee Warbler
This adult Tennessee Warbler appears to be adorned in a very worn set of plumage…
Tennessee Warbler
…and its traveling companion looks like it’s overdue for a new set of feathers as well.
Nashville Warbler
Like the Tennessee Warbler, the Nashville Warbler was common among mixed flocks.
Nashville Warbler
A Nashville Warbler atop a Black Cherry.
Chestnut-sided Warbler
This Chestnut-sided Warbler was one of several found among the more common species of migrants.
Chestnut-sided Warbler
A Chestnut-sided Warbler.
Chestnut-sided Warbler
We were lucky enough to spot this male Chestnut-sided Warbler sporting his namesake flank feathers.
 Black-and-white Warbler
A Black-and-white Warbler uses its nuthatch-like feeding behavior to search the tree bark for edible invertebrates.
Common Yellowthroat
To see the Common Yellowthroat, one must cease looking upward into the high canopy and instead give the aching neck a rest by peering into the low vegetation at the forest edge.
Magnolia Warbler
While checking the low growth, keep an eye open for other migrants among the shrubs and tangles. This Magnolia Warbler glows in the rays of a rising sun as it searches for a meal after a long night of travel.
House Wren
Here we found a perky little House Wren.
Eastern Wood-Pewee
Back in the middle and upper reaches of the trees, we find what has been by far the most numerous of the flycatchers seen during our visits to fallout sunrises.  Eastern Wood-Pewees are appearing in very good numbers and can be seen quarreling and battling for hunting perches from which they are ambushing flying insects.
 Eastern Wood-Pewee
An Eastern Wood-Pewee fiercely defending its hunting perch.
Eastern Wood-Pewee
An Eastern Wood-Pewee.
Least Flycatcher
The numbers of migrating Least Flycatchers and other members of the genus Empidonax may be reaching their seasonal peak this week.
Scarlet Tanagers
Scarlet Tanagers are currently a common find following nocturnal flights.
Scarlet Tanager
A Scarlet Tanager peers down from the top of a Red Maple.
Rose-breasted Grosbeak
Did you hear a loud squeak in the treetops?  It could be a southbound Rose-breasted Grosbeak stopping by for the day.
Rose-breasted Grosbeak
A Rose-breasted Grosbeak in a dead tree snag.
Swainson's Thrush
The Neotropical thrushes are beginning to move south now as well.  We found this newly arrived Swainson’s Thrush at Rocky Ridge County Park in York County during sunrise this morning.
Red-eyed Vireo
Not surprisingly, the Red-eyed Vireo is one of the most numerous of the migrants seen feeding in the deciduous canopy following a nocturnal flight event.  It’s not at all unusual to see dozens filing the trees around a ridgetop overlook or along a forest edge.  Be certain to check these congregations carefully, especially the groups of birds feeding in the lower branches of tall timber or in the tops of smaller trees.  This week we found…
Yellow-throated Vireo
…several hungry Yellow-throated Vireos arriving after nocturnal flights,…
Philadelphia Vireo
…and a Philadelphia Vireo (Vireo philadelphicus) at the hawkwatch at Rocky Ridge County Park in York County.
Red-breasted Nuthatch
Though not a Neotropical migrant, the easier-heard-than-seen Red-breasted Nuthatch is beginning to wander south into the lower Susquehanna region.  Most of these birds will eventually continue on to the pine forests of the southern United States for winter, but a few could remain to become seasonal visitors at feeding stations.
Ruby-throated Hummingbird
Ruby-throated Hummingbirds are on the move; their migration to the tropics is well underway and nearing its peak.  Ruby-throats are diurnal migrants that do a majority of their flying during the hours of daylight.  The notable exception: the nighttime portion of the long southbound flight some of the birds make to cross the Gulf of Mexico.
Red-headed Woodpecker
The Red-headed Woodpecker is another diurnal migrant.   This denizen of temperate climates is currently beginning to move to its wintering grounds, an area that extends from the latitudes of the lower Susquehanna south to the Gulf of Mexico and central Texas.
Juvenile Red-headed Woodpecker
A juvenile Red-headed Woodpecker during a brief pit stop.
Cedar Waxwings
The flights of roving bands of masked Cedar Waxwings continue.  Their numbers appear to be an improvement over those of 2023.
Broad-winged Hawk
At regional hawk-counting stations, observers are seeing more Broad-winged Hawks and other species beginning to move through.
"Kettling" Broad-winged Hawks
The frequency of Broad-winged Hawks passing the lookouts one at a time is giving way to the occurrence of larger and larger “kettling” groups that search out thermal updrafts to save energy while migrating.  By mid-September each of these “kettles” can include one hundred birds or more.  On the peak days, the daily Broad-winged Hawk totals can reach one thousand or more.
Broad-winged Hawk
A Broad-winged Hawk soaring to gain lift from a thermal updraft above a hawkwatch lookout.

The migration is by no means over; it has only just begun.  So plan to visit a local hawkwatch or other suitable ridgetop in coming weeks.  Arrive early (between 7 and 8 AM) to catch a glimpse of a nocturnal migrant fallout, then stay through the day to see the hundreds, maybe even thousands, of Broad-winged Hawks and other diurnal raptors that will pass by.  It’s an experience you won’t forget.

Broad-winged Hawk Gliding Away to the Southwest
A Broad-winged Hawk gliding away to the southwest.

Be certain to click the “Birds” tab at the top of this page for a photo guide to the species you’re likely to see passing south through the lower Susquehanna valley in coming months.  And don’t forget to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab to find a hawk-counting station near you.

More birds are on the way.  Here’s a look at this evening’s liftoff of nocturnal migrants detected by National Weather Service Radar in State College, Pennsylvania.  (NOAA/National Weather Service Doppler Radar image)

Aphrodite Fritillary

The Aphrodite Fritillary (Speyeria aphrodite), also known simply as the Aphrodite, is a brush-footed butterfly of deciduous, coniferous, and mixed forests.  We found this female in a grassland margin between woodlots where prescribed fire was administered during the autumn of 2022 to reduce accumulations of natural fuels and an overabundance of invasive vegetation.  A goal of the burn was to promote the growth of native species including the violets (Viola species) favored as larval host plants by this and other fritillaries.

Aphrodite Fritillary
A female Aphrodite Fritillary collecting nectar from a thistle flower.

By the time these adult butterflies make their reproductive flights in late summer, the violets that serve as larval host plants have gone dormant.  To find patches of ground where the violets will come to life in spring, the female Aphrodite Fritillary has an ability to sense the presence of dormant roots, probably by smell.  Upon finding an area where suitable violets will begin greening up next year, she’ll deposit her eggs.  The eggs overwinter, then hatch to feed on the tender new violet leaves of spring.

Aphrodite Fritillary
A female Aphrodite Fritillary.  A prescribed burn, when administered during spring to manage fritillary habitat, is applied only to a portion of the land parcel each year to avoid decimating an entire population of the larvae during the first instar of their life cycle, a time when they are vulnerable to fire.
Aphrodite Fritillary
Our female Aphrodite Fritillary busily gathers nutritious nectar to provide sufficient energy for the critical process of mating and egg production.  What’s the thistle that this goddess of love and procreation is pollinating?…It’s a non-native invasive, the Bull Thistle (Cirsium vulgare), a species that readily colonizes new areas by producing an abundance of airborne seeds.  Continued management of this site with periodic applications of prescribed fire will prevent Bull Thistle and other invasives from overtaking the habitat during coming years.

Southbound Flights: On Their Way Both Night and Day

It’s hard to believe, but for almost two months now, sandpipers, plovers, and terns have been filtering south through the Lower Susquehanna River Watershed on their way to the Atlantic coastline as they complete the first leg of their long autumn migration—a journey that will take some species all the way to the far reaches of the South American continent for winter.

Caspian Terns and Osprey
Migrating Caspian Terns and an Osprey take a break on a lower Susquehanna valley gravel bar.

As August draws to a close, these early birds are being joined by widespread nocturnal flights of Neotropical migrants—those species, primarily songbirds, on their way to wintering grounds which lie exclusively south of the continental United States.

To catch a glimpse of these night-flying avians, your best bet may be to position yourself on the crest of a ridge or along a linear break in the forest such as a utility right-of-way where waves of warblers, vireos, flycatchers, and other Neotropical passerines sometimes feed on invertebrates after making landfall at daybreak.  Pick a place where the trees are bathed in the warm light of the rising sun and be there by 7 A.M. E.D.T.  The activity can be tremendous, but it usually ends between 8 and 9.

Red-eyed Vireo
One of more than half a dozen Red-eyed Vireos seen during a daybreak fallout at Second Mountain Hawkwatch in Lebanon County earlier this week.
Blackburnian Warbler
During sunrise, a just-arrived Blackburnian Warbler checks the foliage of a ridgetop Red Maple for insects.
Least Flycatcher
A Least Flycatcher quietly searches the shrubby growth along the forest edge for a morning meal.
Black-and-white Warbler
A Black-and-white Warbler in the first hour of sunlight after a big nocturnal flight.
Scarlet Tanager
A Scarlet Tanager having a look around.  This individual and other migrating birds may be here for a few days before moving on.
Black-throated Green Warbler
A Black-throated Green Warbler in a treetop glowing with the light of sunrise.
Chestnut-sided Warbler
A hungry Chestnut-sided Warbler inspects limbs, leaves, and twigs looking for nourishment after an all-night flight.

Diurnal migrants, birds that make their movements during the daylight hours, are ramping up their flights now as well.  Broad-winged Hawks, Bald Eagles, and falcons are currently being tallied at hawk-counting stations throughout the northeast.  Many of those lookouts are seeing Ruby-throated Hummingbirds, swallows, and other daytime migrants too.

Broad-winged Hawk
While many diurnal migrants gather in flocks as a method of defense against predators, Broad-winged Hawks congregate as a reconnaissance measure.  Not waiting around for strong autumn winds to be deflected upwards by the region’s numerous ridges, these Neotropical birds migrate early enough in the season to rely upon thermal updrafts from sun-heated surfaces to provide lift, gain altitude, and save energy during their long trip.  By traveling in groups, there are collectively able to better locate and utilize rising air columns as they progress southwesterly along their route.  Broad-winged Hawks travel to Central and South America for winter.  Their numbers in the Lower Susquehanna River Watershed will peak during the third week of September.
American Kestrel
Many American Kestrels transit our area in August and early September, a time coinciding with flights of migratory dragonflies, insects upon which they and another falcon, the Merlin, frequently prey.
Chimney Swifts
Chimney Swifts are fast-flying diurnal migrants.  They are beginning to congregate into larger groups in preparation for their departure.  Some are already on the move.
Cedar Waxwing
Cedar Waxwings are currently being seen in roving flocks throughout the region.  Their migration is less of a point-to-point flight and more of a continuous wandering in search of berries and other wild foods.
American Goldfinch
Not everyone is yet ready to go.  American Goldfinches are still in the midst of their nesting cycle and won’t begin leaving until the young are on their own and colorful adult males like this one are beginning to molt into their drab winter plumage.

Autumn migration flights are an ever-changing process, with different species peaking at different times throughout the season.  In these months just after the nesting season, each of these species is more numerous than at any other time of the year.  And of course, the more often we as observers get out and have a look, the more of them we’ll see.

Be certain to click the “Birds” tab at the top of this page for a photo guide to the species you’re likely to see passing through the lower Susquehanna valley this fall.  Nearly four months of autumn hawk migration flights lie ahead, so don’t forget to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab to find a hawk-counting station near you, then stop by for a visit or two.  See you there!

A large nightfall liftoff of nocturnal migrating birds is shown here on this evening’s State College, Pennsylvania, Doppler Radar base velocity loop.  Returns indicating birds moving toward the radar site (the white dot in the center of the color mass) are shown in green, and those indicating birds moving away are indicated in red.  This is a big flight headed generally in a south-southwest direction.  (NOAA/National Weather Service Doppler Radar image)

Wildflower Meadow Update

Do you recall our “Photo of the Day” from seven months ago…

Riverfront Park Wildflower Meadow
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!

Well, here’s what that site looks like today…

Riverfront Park Wildflower Meadow
The wildflowers, thousands of them, are now in bloom!
Riverfront Park Wildflower Meadow
Black-eyed Susan and Blue Vervain (Verbena hastata) dominate the assortment currently in flower.

And there are pollinating insects galore, most notably butterflies…

Cabbage White
A Cabbage White collecting nectar on Blue Vervain.
A Sulphur
A Clouded or Orange Sulphur among the grasses in the meadow.
Silver-spotted Skipper
A Silver-spotted Skipper.
Least Skipper
The Least Skipper is our tiniest butterfly.
Little Glassywing
The Little Glassywing (Vernia verna), this one feeding on vervain nectar, deposits its eggs on Purpletop grass, which then functions as the host plant for this butterfly’s larvae.
Summer Azure
A Summer Azure (Celastrina neglecta) feeding on the nectar of a Black-eyed Susan.
Common Buckeye
A Common Buckeye on a “Gloriosa Daisy”, a showy, large-flowered cultivar of Black-eyed Susan.
Red-winged Blackbird
A Red-winged Blackbird with a caterpillar found among the meadow’s lush growth.
Tiger Swallowtail
An Eastern Tiger Swallowtail on Blue Vervain.  Nearby Yellow (Tulip) Poplars and other trees serve as host plants for this butterfly’s larvae.
Black Morph Eastern Tiger Swallowtail
The black morph of the Eastern Tiger Swallowtail shows subdued shading in the wings that closely resembles the brilliant color patterns of the more familiar yellow form.
Sachem
The Sachem, this one visiting a Black-eyed Susan, is a variable species with a range that normally lies south of the 40th parallel, the line of latitude that intersects the Susquehanna in the area of the Conejohela Flats at Washington Boro.
A Sachem visiting the blooms of Oxeye sunflower.   During recent weeks, scorching winds from the south and southwest have transported an abundance of these vagrant skippers into the lower Susquehanna valley and beyond.
Sachem
A male Sachem approaching the bloom of a “Gloriosa Daisy”.  Miles north of the 40th parallel, wandering Sachems are currently the most numerous of the butterflies at the Riverfront Park wildflower meadow.
Partridge Pea
Here and there among the meadow’s plantings we noticed one of our favorites starting to flower, the Partridge Pea.
Cloudless Sulphur
Partridge Pea happens to be a host plant for another vagrant from the south, the big, lime-yellow Cloudless Sulphur.  We saw at least half a dozen patrolling the meadow.
Zebra Swallowtail
The stars of the show are the Zebra Swallowtails, gorgeous butterflies that rely on stands of native Common Paw-paw trees in the river floodplain to host their eggs and larvae.
Zebra Swallowtail
The red-white-and-blue underside of a Zebra Swallowtail.
Zebra Swallowtail
WOW!

Why on earth would anyone waste their time, energy, and money mowing grass when they could have this?  Won’t you please consider committing graminicide this fall?  That’s right, kill that lawn—at least the majority of it.  Then visit the Ernst Seed website, buy some “Native Northeast Wildlflower Mix” and/or other blends, and get your meadow planted in time for the 2025 growing season.  Just think of all the new kinds of native plants and animals you’ll be seeing.  It could change your life as well as theirs.

Snowberry Clearwing
A Snowberry Clearwing (Hemaris diffinis), more commonly known as a hummingbird moth, visits the flowers of Blue Vervain in the Riverfront Park wildflower meadow.

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 (Salix nigra), 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

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.

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!

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.

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.