Category: Flowering Plants (Angiosperms)

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Changes Following the Season’s First Frost

Having experienced our first frost throughout much of the lower Susquehanna valley last night, we can look forward to seeing some changes in animal behavior and distribution in the days and weeks to come.  Here are a few examples…

Northern Rough-winged Swallows
Unlike their close relatives the Tree Swallows, which include berries as well as invertebrates in their diet, Northern Rough-winged Swallows are strictly insectivores and will find it necessary to promptly move south to assure a frost-free environment where they can secure an adequate supply of food.  Their one alternative: find a local sewage treatment plant where warm water attracts populations of flying insects through the remainder of autumn and maybe into winter.
Yellow-rumped Warbler
Warblers too are insect eaters.  Look for most of our dozens of species to evacuate the area in coming days and leave behind only the Yellow-rumped Warbler, another bird with a fondness for berries during cold weather.   Into the winter months, they remain in small numbers in habitats with an abundant supply of berries like Poison Ivy, holly, wild grape, bittersweet, and Eastern Red Cedar.  For lingering Yellow-rumped Warblers, thickets of cedars and other evergreens provide essential protection from frigid nighttime winds.
Eastern Chipmunk
This Eastern Chipmunk will soon feel the pinch.  Instead of eating the sweet, fruity portions of Mile-a-minute Weed berries, it’ll have to get serious about stocking its den with larger seeds, acorns, hickory nuts, and other foods to snack on through the winter.  Better get busy, little friend!
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Tropical Treats and an Early Surprise

Crisp cool nights have the Neotropical birds that visit our northern latitudes to nest during the summer once again headed south for the winter.

Flying through the night and zipping through the forest edges at sunrise to feed are the many species of migrating vireos, warblers, and other songbirds.

Tennessee Warbler
A Tennessee Warbler peers from the cover of a Staghorn Sumac (Rhus typhina), a small native tree which is not, as many assume, a poisonous plant.  Staghorn Sumac is in fact an excellent wildlife species with brilliant autumn colors.
Yellow-throated Vireo
Though its breeding season has come to an end, this southbound Yellow-throated Vireo was found singing its heart out in the limbs of a Staghorn Sumac early this morning.
Northern Parula
Not to be outdone, this Northern Parula joined in with a cheery tune from yet another Staghorn Sumac.
Black-throated Green Warbler
Black-throated Green Warblers are particularly numerous right now.  To see them, visit a ridgetop forest clearing at sunrise.

As the nocturnal migrants fade into the foliage to rest for the day, the movement of diurnal migrants picks up the pace.

Ruby-throated Hummingbird
Southbound flights of Ruby-throated Hummingbirds are reaching their peak this week with chilly temperatures hustling them along.  Remember to keep your feeders clean and your nectar fresh through at least early October; they may really need the supplemental energy.
Broad-winged Hawks
Migrating Broad-winged Hawks, sometimes traveling in large flocks known as kettles, seek out thermal updrafts to gain altitude before gliding away on a southwest heading bound for Houston, Texas.  Once there, they’ll make a turn to the south and follow the gulf coastline toward the tropics for winter.
Broad-winged Hawks
While passing through the lower Susquehanna valley in fall, Broad-winged Hawks can be seen ascending to greater heights above almost any sun-drenched surface including large parking lots or barren fields.  But to get your best look, visit a ridgetop hawk watch where these birds circle on the rising air created by solar heating of the south-facing slopes.
Sharp-shinned Hawk
While on the crest, you might notice that the Neotropicals aren’t the only bird species heading through.  Migrants like this Sharp-shinned Hawk are beginning to show up in increasing numbers with a peak expected in about two to three weeks.

To find a hawk-counting station near you, check out our “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” page by clicking the tab at the top of this page.  And plan to spend some time on the lookout during your visit, you never know what you might see…

Second-year Golden Eagle
This very early Golden Eagle surprised observers at Second Mountain Hawk Watch in Lebanon County, Pennsylvania, this morning.  It appears to be an immature, more specifically a second-year bird beginning molt (replacing its innermost primaries), so it may not have traveled all the way to the eastern population’s breeding areas in northern Canada for the summer.  Instead, it may have wandered the vast wilderness hundreds of miles further south.  Expect to see these regal eagles more regularly when adults and hatch-year juveniles from the nesting region start passing through our area, primarily during the period between Halloween and Thanksgiving.  In the meantime, you’ll have time to check out our “Aging Golden Eagles” page by clicking the tab at the top of this page.
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It’s Prime Time for Hummingbirds

Ruby-throated Hummingbird at Scarlet Bee Balm
Now that the nesting season is drawing to a close, Ruby-throated Hummingbirds are a bit less fussy about where they spend their time.  Even in urban settings, gardens with an abundance of nectar-producing flowers like this Scarlet Bee Balm (Monarda didyma) have a good chance of attracting them.  Hummingbirds will be wandering the landscape and starting to drift south during the coming two months, so keep your feeders clean and filled with a fresh blend of sugar water to keep them energized and happy.  If you’re feeding hummingbirds, or thinking about feeding hummingbirds, be sure to review the helpful tips contained in our post from August 5, 2022, “Two Feeders Are Better Than One”.  Their health and your peace of mind may depend on it.
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Sorry, But We Have No Steamed Crabs Today

Goldenrod Crab Spider
Earlier today, we collected some mint leaves from the garden to make a batch of iced tea.  Just prior to plunging them into boiling water, we noticed this Goldenrod Crab Spider (Misumena vatia) hiding in the foliage.
Goldenrod Crab Spider
Goldenrod Crab Spiders live among the stems and leaves of flowering plants.  They are particularly fond of goldenrods, milkweeds, and other species that attract an abundance of flying insects.  When the plants bloom, the spiders will use their white or yellow coloration to hide among the petals and disks of the flowers.  From there, they ambush the visitors that stop by for a sample of nectar or pollen.  In an effort to lure prey directly into their clutches, these acrobatic arachnids will even dangle among the clusters of blossoms with their legs spread like petals surrounding their disk-like body.  This behavior helps inspire their other common name: Flower Crab Spider. 
Goldenrod Crab Spider
Needless to say, this crab was spared the pot and instead returned to the garden to help keep the plants healthy and ecosystem in balance in our wildflower patch.  So we’ll just be having tea, thank you.
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Brood XIV Periodical Cicada Wrap Up

While the heat and humidity of early summer blankets the region, Brood XIV Periodical Cicadas are wrapping up their courtship and breeding cycle for 2025.  We’ve spent the past week visiting additional sites in and near the Lower Susquehanna River Watershed where their emergence is evident.

We begin in York County just to the west of the river and Conewago Falls in mostly forested terrain located just southeast of Gifford Pinchot State Park.  Within this area, often called the Conewago Hills, a very localized population of cicadas could be heard in the woodlands surrounding the scattered homes along Bull Road.  Despite the dominant drone of an abundance of singing Pharaoh Periodical Cicadas, we were able to hear and record the courtship song of a small number of the rare Little Seventeen-year Cicadas.  Their lawn sprinkler-like pulsating songs help mate-seeking males penetrate the otherwise overwhelming chorus of the Pharaoh cicadas in the area.

Little Seventeen-year Cicada
The Little Seventeen-year Cicada’s (Magicicada septendecula) thorax is black between the eye and the origin of the wings.  It is the rarest of the three species of seventeen-year cicadas.
Little Seventeen-year Cicada
The underside of male (left) and female (right) Little Seventeen-year Cicadas shows narrow orange edges on the abdominal segments.

From the Conewago Hills we moved northwest into the section of southern Cumberland County known as South Mountain.  Here, Pharaoh Periodical Cicadas were widespread in ridgetop forests along the Appalachian Trail, particularly in the area extending from Long Mountain in the east through Mount Holly to forests south of King’s Gap Environmental Education Center in the west.

Pharaoh Periodical Cicadas
Pharaoh Periodical Cicadas along the Appalachian Trail on South Mountain, Cumberland County, Pennsylvania.  Like the cicadas we visited last week on the east side of the Susquehanna, this population is surviving on lands with a history of timber harvest and charcoal production to fuel nearby iron furnaces during the nineteenth century.

While on South Mountain, we opted for a side trip into the neighboring Potomac watershed of Frederick County, Maryland, where these hills ascend to greater altitude and are known as the Blue Ridge Mountains, a name that sticks with them all the way through Shenandoah National Park, the Great Smoky Mountains, and to their southern terminus in northwestern Georgia.  We found a fragmented emergence of Pharaoh Periodical Cicadas atop the Catoctin Mountain section of the Blue Ridge just above the remains of Catoctin Furnace, again on lands that had been timbered to make charcoal to fuel iron production prior to their protection as vast expanses of forest.

Pharaoh Periodical Cicada
A Pharaoh Periodical Cicada on Catoctin Mountain near Catoctin Furnace south of Thurmont, Maryland.  These cicadas are not part of a Brood XIV emergence, but are instead a population of Brood X (2021) stragglers.
Pharaoh Periodical Cicada
A female Brood X Pharaoh Periodical Cicada straggler on Catoctin Mountain.  The website “cicadamania.com” notes, “Experts (Gaye Williams, State Entomologist of Maryland, John Cooley of UCONN) have confirmed that there will be no Brood XIV cicadas for Maryland.”

Back in Pennsylvania, we’re on our way to the watersheds of the northernmost tributaries of the lower Susquehanna’s largest tributary, the Juniata River.  There, we found Brood XIV cicadas more widespread and in larger numbers than occurred at previous sites.  Both Pharaoh and Cassin’s Periodical Cicadas were seen and heard along Jack’s Mountain and the Kishacoquillas Creek north of Lewistown/Burnham in Mifflin County.  To the north of the Kishacoquillas Valley and Stone Mountain in northernmost Huntingdon County, the choruses of the two species were again widespread, particularly along the forest edges in Greenwood Furnace State Park, Rothrock State Forest, and adjacent areas of the Standing Stone Creek watershed.

Tymbal on the male Pharaoh Periodical Cicada
A view of the sound-generating tymbal on a male Pharaoh Periodical Cicada at Greenwood Furnace State Park.  Rapid vibration of the tymbals by a set of specialized muscles generates the distinctive calls and courtship songs of the various cicada species.  When handled, these tymbals can produce a harsh “panic call”.  This distress sound could startle a would-be predator and provide the cicada with an opportunity to escape.
Tymbal on a Cassin's Periodical Cicada
The sound organs comprised of ribbed tymbals and specialized muscles on the male Cassin’s Periodical Cicada generate a “panic call” as well as the distinctive calls and songs used to penetrate the droning choruses of the more numerous Pharaoh Periodical Cicadas with which it shares a seventeen-year flight.
Cassin's Periodical Cicadas
Using their specialized sound organs, Cassin’s Periodical Cicadas generate a courtship song that usually includes buzzy phrases and ticking notes (first sound clip).  The buzzing and ticking helps the male Cassin’s cicada penetrate the songs of the more numerous Pharaoh Periodical Cicadas in the area (second sound clip).  When synchronized into a chorus that surges in volume, the songs of Cassin’s Periodical Cicadas can overcome the overwhelming drone of the nearby Pharaoh cicadas (third sound clip).
Pharaoh Periodical Cicada Depositing Eggs
After mating and before the lives of these seventeen-year cicadas draw to a close, the females need to deposit their fertilized eggs into the small end twigs of suitable trees.  On a small hawthorn tree (Cretaegus species) along the edge of the forest at Greenwood Furnace State Park, this Pharaoh Periodical Cicada is using her ovipositor to make a slit in a twig and place her eggs.
Cassin's Periodical Cicada Ovipositing
Simultaneously on the same little hawthorn tree, this female Cassin’s Periodical Cicada is depositing her fertilized eggs.

Within the last 48 hours, we visited one last location in the Lower Susquehanna River Watershed where Brood XIV Periodical Cicadas have emerged during 2025.  In the anthracite coal country of Northumberland County, a flight of Pharaoh Periodical Cicadas is nearing its end.  We found them to be quite abundant in forested areas of Zerbe Run between Big and Little Mountains around Trevorton and on the wooded slopes of Mahanoy Mountain south of nearby Shamokin.  Line Mountain south of Gowen City had a substantial emergence as well.

Pharaoh Periodical Cicada
A Brood XIV Pharaoh Periodical Cicada near Zerbe Run west of Trevorton, Northumberland County, Pennsylvania.  The following sound clip features the fading chorus of these cicadas and some of the nesting birds that may actually be preying upon them: Yellow-billed Cuckoo, Red-eyed Vireo, and Northern Cardinal.   
Foliage with Evidence of Ovipositing
Brown leaves reveal the end twigs where female Pharaoh Periodical Cicadas have deposited eggs during the last several weeks.  During July, the larvae will hatch and drop to the ground to start a new generation of Brood XIV cicadas.  As subterranean nymphs, they’ll spend the coming seventeen years feeding on small amounts of xylem sap from tree roots.  In 2042, during the next Brood XIV emergence, these nymphs will come to the surface and take flight as adults.
Foliage with Evidence of Ovipositing
Evidence of egg deposition among foliage on Line Mountain at State Game Lands 229.
Dead Pharaoh Periodical Cicadas
Accumulations of deceased Pharaoh Periodical Cicadas on Line Mountain.
Eastern Gartersnake
Fallen cicadas that show any sign of life are being snatched up by predators such as this Eastern Gartersnake (Thamnophis sirtalis sirtalis).  Meanwhile, the remainder of the biomass is picked apart by scavengers or is left to reducers for breakdown into fertilizer and organic matter for the forest.  Nothing goes to waste.

To chart our travels, we’ve put together this map plotting the occurrence of significant flights of Periodical Cicadas during the 2025 emergence.  Unlike the more densely distributed Brood X cicadas of 2021, the range of Brood XIV insects is noticeably fragmented, even in areas that are forested.  We found it interesting how frequently we found Brood XIV cicadas on lands used as sources of lumber to make charcoal for fueling nineteenth-century iron furnace operations.

Greenwood Furnace
The furnaces at Greenwood Furnace State Park required the daily cutting of one acre of timber to make enough charcoal to fuel the iron-making process.  Did keeping thousands of acres in various stages of forest succession to supply the charcoal needs of these operations aid the survival of earlier generations of Periodical Cicadas on these lands?  Or, after the furnaces converted to coal for fuel, did the preservation of many of these parcels as state, federal, and private forests allow the cicadas to find refuge from the widespread impacts of agriculture and expanding urbanization in adjacent lands?  Maybe it’s a little of both.  We always bear in mind that annual insects and other animals are more than one hundred generations removed from the negative or positive impacts of the early years of the industrial age, but only about ten generations have passed since populations of seventeen-year Periodical Cicadas were directly influenced by these factors.  What do you think?

Well, that’s a wrap.  Please don’t forget to check out our new Cicadas page by clicking the “Cicadas” tab at the top of this page.  Soon after the Periodical Cicadas are gone, the annual cicadas will be emerging and our page can help you identify the five species found regularly in the lower Susquehanna valley.  ‘Til next time, keep buzzing!

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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 with her wings 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 surging 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 on State Game Lands 170.  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!

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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.
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Photo of the Day

Common Carp
We came across this photo from a dive we did back in 1999 and thought it timely.  Here a large non-native Common Carp churns up a cloud of nutrient-charged sediment as it roots its way through a bed of American Eelgrass and Water Stargrass in the Susquehanna below Conewago Falls.  (Vintage 35 mm image)
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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.
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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.

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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.
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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.
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Back in the Day: Down on the Farm

Let us travel through time for just a little while to recall those sunny, late-spring days down on the farm—back when the rural landscape was a quiet, semi-secluded realm with little in the way of traffic, housing projects, or industrialized agriculture.  Those among us who grew up on one of these family homesteads, or had friends who did, remember the joy of exploring the meadows, thickets, soggy springs, and woodlots they protected.

Low-intensity Farming
During much of the twentieth century, low-intensity agriculture provided a haven for wildlife.  Periodic disturbances helped maintain cool-season grassland and early successional habitat for a number of species we currently find in decline.

For many of us, farmland was the first place we encountered and began to understand wildlife.  Vast acreage provided an abundance of space to explore.  And the discovery of each new creature provided an exciting experience.

Distributed by the Pennsylvania Game Commission, artist Ned Smith’s wildlife posters introduced many residents of the lower Susquehanna region to its birds and mammals.  This poster of “Birds of Field and Garden” helped us learn what to expect and search for during our forays to the farm.

Today, high-intensity agriculture, relentless mowing, urban sprawl, and the increasing costs and demand for land have all conspired to seriously deplete habitat quality and quantity for many of the species we used to see on the local farm.  Unfortunately for them, farm wildlife has largely been the victim of modern economics.

For old time’s sake, we recently passed a nostalgic afternoon at Middle Creek Wildlife Management Area examining what maintenance of traditional farm habitat has done and can do for breeding birds.  Join us for a quick tour to remember how it used to be at the farm next door…

Barn Swallow
Always found nesting under the forebay of the barn, the Barn Swallow relentlessly pursued flying insects over the pond and meadow.
Eastern Meadowlark
Eastern Meadowlarks arrived during March and April to begin nesting in their namesake.  Their song, “spring-of-the-year”, heralded the new season.
Eastern Kingbird
Arriving in meadows and pastures during early May, the Eastern Kingbird provided for its nestlings by ambushing a variety of flying insects.  By August, congregations of these birds could be found gathering along ponds and streams ahead of their fall migration.
Orchard Oriole
In the cherry grove down by the creek, the Orchard Oriole would be singing incessantly to defend its territory.
American Goldfinches
Normally seed eaters through the colder months, American Goldfinches would regularly find a source of protein in the occupants of Eastern Tent Caterpillar nests.
Yellow Warbler
Along the wet margins of the creek, Yellow Warblers would nest in the shrubs and small trees.
Willow Flycatcher
The “Traill’s Flycatcher” was a familiar find in low-lying areas of successional shrubs and small trees.  Today, “Traill’s Flycatcher” is recognized as two distinct species, the Alder Flycatcher (Empidonax alnorum) and the Willow Flycatcher.  In the lower Susquehanna valley, the latter (seen here) is by far the most common of the two.
Eastern Bluebirds
During the nineteenth century, Eastern Bluebirds became a rarity on lower Susquehanna farms due to a combination of factors: pesticide (DDT) use, habitat loss, and competition with other birds for nest sites.  The species saw a resurgence beginning in the 1970s with discontinuation of DDT applications and widespread provision of nesting boxes.  Around human habitations, competition with invasive House Sparrows continues to be detrimental to their success.
Purple Martins and Tree Swallows
Purple Martins suffered a similar fate to the bluebirds.  The potential for their recovery remains dubious and they continue to be very local breeders, fussy about selection of suitable man-made provisions for nesting.  After considerable effort, Purple Martins have at last been attracted to nest in the condos placed for their use at Middle Creek Wildlife Management Area.  In the artificial gourds, there are nesting Tree Swallows, a species which also benefits from the placement of boxes intended for bluebirds.
Field Sparrow
Abandoned fields and other successional habitats were and continue to be favored homes for Field Sparrows.
Cedar Waxwing
At almost any time of year, roving bands of Cedar Waxwings would suddenly visit old field habitat looking for berries among the shrubs and other pioneering woody growth.  In early summer, after most species have already hatched their young, nesting would commence and these fruit eaters would transform into accomplished fly catchers.
Ring-necked Pheasant
During the twentieth century prior to the 1980s, Ring-necked Pheasant populations in the Lower Susquehanna River Watershed were comprised of breeding descendants of introduced birds supplemented by additional releases to maintain numbers sufficient for hunting.  Year-round populations did and can reside in mosaic landscapes of early successional and grassland habitats, the latter including hay fields left unmowed through the nesting season.
Red-winged Blackbird
Red-winged Blackbirds have always been a fixture of hay fields and meadows on farms.  While the increase in mowing frequency has reduced their nesting success, they have persevered as a species by nesting earlier than other birds and by utilizing other landscape features such as densely vegetated stormwater basins for breeding sites.
Bobolink
Do you recall the last time you saw a Bobolink nesting in a hay field near you?  Arriving in early May as a Neotropical migrant, the Bobolink requires a cool-season grassland such as hay field through at least July to complete its nesting cycle.  Even earlier this century, we remember nesting Bobolinks being more widespread on farms throughout the region.  Now, you almost have to go to Middle Creek if you want to see them.
Grasshopper Sparrow
Formerly more widespread in hay fields throughout the lower Susquehanna valley, the native Grasshopper Sparrow is yet another species falling victim to early mowing and intensive farming.
Grasshopper Sparrow
The solution to their dilemma is as advertised.  Instead of cutting the grass, why not take heed of the example set here and cut back on the tens of thousands of acres that are excessively or needlessly mowed in the Lower Susquehanna River Watershed?  How ’bout letting a significant percentage of your property regenerate as successional habitat as well?  It can and does make a difference!
Cool-season Grasses
Beautiful cool-season grasses waving in the spring breeze.  Meadows and hay fields can be managed to function as cool-season grasslands to provide nesting opportunities for many of the species we used to find down on the farm.
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Nest Builders at Work

For many animals, an adequate shelter is paramount for their successful reproduction.  Here’s a sample of some of the lower Susquehanna valley’s nest builders in action…

Pileated Woodpecker Excavating Nest
Many of our year-round resident bird species get a head start on the breeding season as cavity nesters.  Some of these mated pairs use naturally occurring hollows, while still others take advantage of the voids left vacant by the more industrious previous occupants.  Woodpeckers in particular are responsible for excavating many of the cavities that are later used as homes by a variety of birds and mammals to both rear their young and provide winter shelter.  Pileated Woodpeckers, like other members of the family Picidae, have an almost mystic ability to locate diseased or insect-infested trees for selection as feeding and nesting sites.  In this composite image, a pair is seen already working on a potential nursery during mid-January.  After use by the woodpeckers, abandoned cavities of this size can become nesting sites for a variety of animals including bees, small owls, Great Crested Flycatchers, Wood Ducks, Hooded Mergansers, and squirrels.
Downy Woodpecker at Nest
After use as a nesting site, a void excavated by Downy Woodpeckers can be occupied in subsequent years by chickadees, titmice, nuthatches, wrens, and other cavity-dwelling species.
Muskrat with Leafy Twig
This Muskrat (Ondatra zibethicus) with a leafy twig in tow takes advantage of spring’s new growth to construct or repair its house,…
Muskrat with Leafy Twig
…a process that can be repeated or renewed as necessary throughout the year.
Muskrat House
A Muskrat house in March.  In the absence of leafy twigs, dried cattail stems will suffice.  As it ages and decays, the house’s organic matter generates heat and makes an ideal location for turtles to deposit and hatch their eggs.
Wood Thrush
Soon after Neotropical migrants begin arriving in the forests of the lower Susquehanna watershed, they begin constructing their nests.  The majority of these species build “outdoors”, not within the confines of a tree cavity.  Here we see a Wood Thrush with its bill full of dried leaves and other materials…
Wood Thrush Nest
…ready to line the cup of its nest in the fork of a small understory tree.
Blue-gray Gnatcatcher
Though it often arrives during early April after spending the winter in sub-tropical and even some temperate climes, the Blue-gray Gnatcatcher must wait to start construction of its nest until many of the Neotropical migrants arrive in early May.
Blue-gray Gnatcatcher
You see, the Blue-gray Gnatcatcher relies on plenty of web-spinning spider activity to supply the construction materials it needs.
Blue-gray Gnatcatcher
A Blue-gray Gnatcatcher pulling apart a spider’s web on a warm May morning.
Blue-gray Gnatcatchers
Back at the nest site…
Blue-gray Gnatcatcher
…the sticky spider webs bind together lichens and small bits of bark…
Blue-gray Gnatcatcher
…to form a perfect little cup for the nesting Blue-gray Gnatcatchers.
Baltimore Oriole with Nesting Material
Baltimore Orioles weave one the most unique nests of any species occurring in eastern North America.
Baltimore Oriole Nest
Unfortunately for them, man-made litter can often seem to be the ideal material for binding the nest together.  In an area only sporadically visited by anglers, this oriole had no trouble finding lots of monofilament fishing line, trash that can fatally entangle both adult and young birds of any species.  If you see any fishing line at all, please pick it up and dispose of it properly.
Baltimore Oriole
Always keep an eye open for fishing line and get it before the birds do!
Brown-headed Cowbirds
Like many other avians, male Brown-headed Cowbirds are now relentlessly pursuing females of their kind.
Brown-headed Cowbirds
All his effort is expended in an attempt to impress her and thus have a chance to mate.
Brown-headed Cowbirds
This male can indeed put all his energy into the courtship ritual because Brown-headed Cowbirds toil not to build a nest.  They instead locate and “parasitize” the nests of a variety of other songbirds.  After mating, the female will lay an egg in a host’s abode, often selecting a slightly smaller species like a Yellow Warbler or native sparrow as a suitable victim.  If undetected, the egg will be incubated by the host species.  Upon hatching, the larger cowbird nestling will dominate the brood, often ejecting the host’s young and/or eggs from the nest.  The host parents then concentrate all their efforts to feed and fledge only the young cowbird.
Indigo Bunting
Watching and waiting.  The Indigo Bunting evades cowbird parasitism by first recognizing the invader’s egg.  They then either add a new layer of nest lining over it or they abandon the nest completely and construct a new one.  Some patient buntings may delay their breeding cycle until after cowbird courting behavior ceases in coming weeks.
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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.
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Singing in the Rain

Neotropical birds are fairly well acquainted with repetitive periods of thundershowers.  With that in mind, we decided not to waste this stormy Tuesday by remaining indoors.

Thundershower
Periods of rain need not put a damper on a day outdoors observing birds that wintered in a rain forest or other tropical environment.
Utility Right-of-way with Successional Habitat
We hiked this utility right-of-way to the north of a heavy thunderstorm and found plenty of activity in the shrubby successional habitat there.
Indigo Bunting
Rain or shine, male Indigo Buntings were busy singing.  All this exuberance is intended not only to establish and defend a nesting territory…
Indigo Bunting
…but to attract the attention of a mate as well.
Blue-winged Warbler
Prior to the implementation of the intensive manicuring practices we see currently applied to most utility right-of-ways, shrubby thickets filled miles of these linear corridors to create a webbed network of early successional growth throughout the lower Susquehanna valley.  Loss of this specialized habitat has led to the almost total elimination of the formerly common Blue-winged Warbler as a breeding species here.
Blue-winged Warbler
We found three male Blue-winged Warblers singing on territories in this bushy clearing where electric transmission lines pass over Third/Stony Mountain on State Game Lands 211.
Blue-winged Warbler
Their presence at this site is testament to the importance of maintaining corridors of quality successional habitat in the landscape.
Blue-winged Warbler
The Blue-winged Warbler is a Neotropical migrant with an easy-to-learn song.  It’s a very simple, buzzy sounding “beeee-bzzz”.
Prairie Warbler
Another Neotropical species that nests in successional thickets is the Prairie Warbler (Setophaga discolor), seen here during one of this morning’s downpours.
Prairie Warbler
The Prairie Warbler can sometimes be found in stands of pioneer plants like Eastern Red Cedar on sites with barren soils or those that have been subjected to wildfire.
Hooded Warbler
The Hooded Warbler is fond of wooded thickets along the edge of forested land such as those in the Third/Stony Mountain utility right-of-way.
Hooded Warbler
The presence of a Mountain Laurel thicket also enhances a forest’s ability to host breeding Hooded Warblers.

We hope you enjoyed our walk in the rain as much as we did.  If you venture out on a similar excursion, please remember this.  The majority of the wild animals around us have busy lives, particularly at this time of year.  Most don’t take a day off just because it rains—that includes ticks.

Female Deer Tick
Be certain to check yourself for ticks, especially these very small Deer Ticks (Ixodes scapularis), also known as Black-legged Ticks.  Deer Ticks are vigilantly looking for something to latch onto, even in the rain, and they can be vectors of Lyme disease.  We found this adult female as a stowaway on the editor’s neck just before heading home from today’s stroll.
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Shad Run at Conowingo Dam

As the Flowering Dogwoods remind us, it’s time for adult sea-run shad and other fishes to ascend the Susquehanna to spawn.  So yep, we’re off to Fisherman’s Park on the river’s west shoreline below Conowingo Dam in Harford County, Maryland, to check it out.

Anglers at Conowingo Dam
Anglers were in the water and seeing action as we arrived below Conowingo Dam’s powerhouse at Fisherman’s Park.  The east lift, which was constructed during the 1990s to raise American Shad and other migratory fish over the dam during their spring spawning runs, sits idle at the impoundment end of the wing wall in the distance.
The entrance to the idle east fish lift at Conowingo Dam.
The entrance to the idle east fish lift at Conowingo Dam.
Northern Snakehead
Within minutes, we watched one of the culprits responsible for the lift’s shutdown being reeled in.  The invasive population of introduced Northern Snakeheads continues to thrive in the waters of the Susquehanna and its tributaries below the dam.  To prevent it from expanding its range to upriver sections of the watershed, all American Shad are being manually separated from among the snakeheads and other fish species deposited into sorting tanks using the west lift near the powerhouse.
Shad Transport Truck
One of several specialized transport vehicles returns from a “shad run” to the waters of the Susquehanna above York Haven Dam at Conewago Falls after delivering and releasing American Shad sorted from among the fish collected at Conowingo’s west lift earlier in the day.
American Shad began their run up the Susquehanna as water temperatures reached 60 degrees Fahrenheit…just about the time the Flowering Dogwoods started to bloom within the river’s riparian woodlands.  Later this month, spawning activity peaks when the water warms to about 65 degrees.  Earlier in the season, when the water reached about 55 degrees, another anadromous species, the Hickory Shad (seen here), began their spring spawning run from sea to freshwater rivers and streams.
While American Shad are seldom caught on hook and line, Hickory Shad are a popular catch-and-release target.  Though they will energetically strike baits like the small shad dart seen here, Hickory Shad are very cautious while ascending the river; they very rarely enter the fish lifts to join the dozens of other species that readily accept their use.  With water temperatures now in the sixties, an angler is seen here bringing in what may be among the last of this season’s Hickory Shad.  Their spawning run is presently drawing to a close for the year.
Gizzard Shad
The most commonly caught herring at Fisherman’s Park is the Gizzard Shad.  This plankton feeder seldom takes bait; it is instead foul-hooked.  Though not a sea-run species, Gizzard Shad by the tens of thousands leave open waters to seek shallower flowing riffles and pools to spawn.
Gizzard Shad
Unlike the other herring occurring in the Susquehanna, the Gizzard Shad has a blunt, snub-nosed appearance to the snout. The mouth is small and often unnoticeable.
Gizzard Shad
The Gizzard Shad is the only species of Susquehanna herring that can legally be harvested.  All others are sea-run migrants in varying degrees of population peril and must be returned to the water without delay.
Gizzard Shad
Note the elongated last ray on the dorsal fin of this foul-hooked Gizzard Shad.  It’s a not-often-visible but nevertheless tell-tale field mark.
Double-crested Cormorant
Humans aren’t the only creatures attracted by the fish migration on the lower Susquehanna.  This is just one of hundreds of Double-crested Cormorants we watched during our visit.
Cormorant along the base of Conowingo Dam
Hungry cormorants gather along the base of the dam where ascending fish congregate and become further disoriented by water turbulence.
Double-crested Cormorants
Fishing efforts here can bring great success to these accomplished piscivores.
Double-crested Cormorant with Gizzard Shad
Latching onto an oversize Gizzard Shad can make you very popular with your peers.
Double-crested Cormorant with Gizzard Shad
So popular that you may never have the opportunity to eat your lunch.
Double-crested Cormorant with Gizzard Shad
Take it from this old bird: you’ve gotta swallow ’em fast, head first, tail and all.
Bald Eagle with Gizzard Shad
A Bald Eagle hauls off a Gizzard Shad.
Osprey with Gizzard Shad
An Osprey saw this Gizzard Shad swimming close enough to the water’s surface to dive in and snag it with its talons.
Bald Eagle with Gizzard Shad
And yet another successful Bald Eagle calls out to its mate as it approaches its nest and hungry young.
Striped Bass
An angler releases a small Striped Bass caught on a shad dart while fishing for Hickory Shad.  To reduce pressure on their populations during the spring spawning run, the “Striper” harvest is presently closed.  The fishing season resumes later this month in some areas, in June within others.  On the Susquehanna Flats and other Chesapeake Bay waters, Striped Bass are also known as “Rockfish”.
Angler in Action
This angler is reeling in a big one.
Channel Catfish
A nice Channel Catfish weighed in at about six pounds and was released.
White Perch
This angler brought in yet another interesting catch.
White Perch
The White Perch (Morone americana) is a bay species that ascends the Chesapeake’s tributaries to spawn during the spring.  On the lower Susquehanna, numbers of this relative of the Striped Bass are falling, very possibly due to depredation by invasive snakeheads, Blue Catfish, and Flathead Catfish.
Double-crested Cormorant with Blue Catfish
A Double-crested Cormorant does its duty and snatches up an invasive Blue Catfish.   Very large Blue Catfish exceeding 24 inches in length are becoming increasingly plentiful on the upper Chesapeake and its tributaries resulting in a significant negative impact on the aquatic ecosystems there.  Like the Northern Snakehead and Flathead Catfish, these invasive species are very palatable and anglers are encouraged to catch and keep as many as they like.
Maryland DNR sign at Fisherman’s Park.
Angler with Northern Snakehead
What can we do about the plague of Northern Snakeheads (Channa argus) in the Susquehanna?  Well, let’s start by answering a question with a question…Why deplete ocean stocks when you can follow this angler’s example and harvest excellent fillets while helping to control an invasive species at the same time?  And no, you don’t have to call them “Chesapeake Channa” if you don’t want to.  Though you will make us laugh if you start calling them “Susquehanna Channa” or  just “Susquechanna” from time to time.
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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.
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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!
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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.
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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,…

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Wildlife in the Burn Zone

During Saturday’s Prescribed Fire Demonstration at the Pennsylvania Game Commission’s Middle Creek Wildlife Management Area, we noticed just how fast some species of wildlife return to areas subjected to burns administered to maintain grassland habitat and reduce the risk of high-intensity blazes.

Back Fire Ignition during prescribed burn demonstration.
Pennsylvania Game Commission crews ignite a back fire to contain a prescribed burn along its downwind/upslope perimeter during a demonstration at Middle Creek Wildlife Management Area on Saturday.
Prescribed Fire Demonstration
Visitors observe a fire planned to maintain this section of the refuge as warm-season grassland.  A species with roots several feet deep, the light-colored vegetation is Indiangrass, a plant adapted to thrive following periodic episodes of wildfire.  Prescribed fire can be used to replace naturally occurring infernos with much safer controlled burns that eliminate successional and invasive plants to promote the establishment of Indiangrass and other native warm-season species including Big Bluestem, Little Bluestem, Switchgrass, and a variety of wildflowers as well.
Prescribed Fire Demonstration
Even as the fire reached its brief peak of intensity, we noticed birds already attracted to the site…
Tree Swallow
Dozens of recently arrived Tree Swallows swept in to patrol for flying insects as the burn was in progress.
Tree Swallow
One even stopped by to have a look inside the kestrel nest box as fire approached the dry stand of goldenrod on the slope behind.
Red-tailed Hawk
Red-tailed Hawks and other raptors, including nocturnal owls, are frequently the first visitors attracted to the scene of a prescribed burn or wildfire.  In grassland and successional habitats, they come looking for any vulnerable voles or mice that may be moving about looking for cover.

Eastern Meadowlarks

Eastern Meadowlarks

Eastern Meadowlarks
These three Eastern Meadowlarks spent the morning in the grassland areas adjacent to the prescribed fire site, mostly where a burn had been conducted one week prior.  During the demonstration, one even perched and sang from the oak trees in the museum/visitor’s center parking lot.

Following the Prescribed Fire Demonstration, we decided to pay a visit to some of the parcels where burns had been administered one week earlier on the north side of Middle Creek’s main impoundment.  We found a surprising amount of activity.

White-crowned and White-throated Sparrows
Apparently feeding upon slightly heat-treated seeds, sparrows were found by the dozens. White-crowned (left), White-throated (right), Song, and Savannah Sparrows were identified.
Downy Woodpecker
This Downy Woodpecker was finding something to its liking among the scorched leaves, stems, and twigs.
American Robins seem to find areas with lightly burnt vegetation and ash-dusted soil advantageous for finding invertebrates following a fire.
Mixed Flock of Blackbirds
We found this flock of Red-winged Blackbirds, Browned-headed Cowbirds, and a few European Starlings feeding throughout a grassland field cleared of early-successional growth by a prescribed fire administered one week ago.
Mixed Flock of Blackbirds
They seemed to favor gleaning seeds from among the lightly burned areas of the plot.
Eastern Meadowlark
Nearby, in an island of unburned grass in the same field, we found yet another Eastern Meadowlark, our fourth of the day.  High-intensity agriculture, particularly early hay mowing and pesticide treatments, have mostly eliminated this and other grassland species from modern farms.  Management practices like prescribed fire and delayed mowing (no spinning blades until at least early August) can maintain ideal grassland habitat for stunningly colorful blackbirds including nesting Eastern Meadowlarks, Bobolinks, and many other species as well.
American Kestrel at Nest Box
A male American Kestrel at a nest box located among Middle Creek’s warm-season and cool-season grassland habitats, the former maintained by prescribed fire, the latter by delayed mowing.
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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.
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They Go Together Like Corned Beef and Cabbage

Red-winged Blackbird
Find a stand of Common Cattails in a marsh, a stormwater basin, or along a pond edge right now and you’re almost certain to find a male Red-winged Blackbird …
Red-winged Blackbird
…singing and displaying to defend a territory and attract a partner.  Upon their arrival and selection of a mate, the brown-streaked females will weave well-hidden nests among the stems and leaves of these essential water-purifying wetland plants.
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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.

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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.
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Purple Finch Irruption?

Each spring and fall, Purple Finches are regular migrants through the Lower Susquehanna River Watershed.  Northbound movements usually peak in April and early May.  During the summer, these birds nest primarily in cool coniferous forests to our north.  Then, in October and November each year, they make another local appearance on their way to wintering grounds in the southeastern United States.  A significant population of Purple Finches remains to our north through the colder months, inhabiting spruce-pine and mixed forests from the Great Lakes east through New England and southeastern Canada.  This population can be irruptive, moving south in conspicuous numbers to escape inclement weather, food shortages, and other environmental conditions.  Every few years, these irruptive birds can be found visiting suburbs, parks, and feeding stations—sometimes lingering in areas not often visited by Purple Finches.  Right now, Purple Finches in flocks larger than those that moved through earlier in the fall are being seen throughout the lower Susquehanna valley.  Snow and blustery weather to our north may be prompting these birds to shift south for a visit.  Here are some looks at members of a gathering of more than four dozen Purple Finches we’ve been watching in Lebanon County this month…

Purple Finches
Purple Finches are easily distinguished from House Finches by their notched tails, darker streaking, and well-defined facial markings.  Though most frequently found in proximity to  conifers, they also visit native deciduous trees and shrubs to snack on berries, seeds, and buds.  Purple Finches can be particularly fond of maple, birch, poplar, sumac, and viburnum.
Purple Finches
Adult male Purple Finches are unmistakable in their wine-colored plumage.
Purple Finches
Purple Finches join a Dark-eyed Junco, a White-throated Sparrow, and a Black-capped Chickadee at a feeding station.
Purple Finches
Purple Finches eating black oil sunflower seed.
Male Purple Finch
A male Purple Finch in successional forest edge habitat consumes seeds from a dried stand of goldenrod.
Purple Finches
Purple Finches with juncos and Northern Cardinals.
Purple Finches
Purple Finches filling up on supplemental foods.
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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.

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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.
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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.

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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.
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Pot o’ Gold on the Ridgetops

Bathed in glowing sunshine, a very large fallout of migrating Neotropical songbirds enlivened the forest edge atop Second Mountain in northern Lebanon County, Pennsylvania, this morning.  While last night’s flight was widespread beneath a dome of atmospheric high pressure covering the Mid-Atlantic States, this is a look at some of the 500 -1,000 migrants observed feeding on insects and other natural foods at just this single location.

Blackpoll and Black-throated Green Warblers
As the composition of the nightly flights begins to transition to species that start their migration later in the season, numbers of birds like the Blackpoll Warbler (top) are beginning to rival those of the heretofore very common Black-throated Green Warbler (bottom).
Blackpoll Warbler
A Blackpoll Warbler.
Bay-breasted Warbler
The Bay-breasted Warbler, another common species found among the fallout flock.
Tennessee Warbler
The Tennessee Warbler was today’s most abundant migrant with at least 200 birds seen moving among the other species.
Tennessee Warbler
A newly arrived Tennessee Warbler at sunrise.
Tennessee Warbler
A Tennessee Warbler snatches breakfast.
Magnolia Warbler
The Magnolia Warbler was another common find among today’s migrants.
Magnolia Warbler
A Magnolia Warbler.
Nashville Warbler
A Nashville Warbler among tangles of Mile-a-minute Weed.
Nashville Warbler
A Nashville Warbler.
Black-throated Blue Warbler
Black-throated Blue Warbler.
Adult Male Black-throated Blue Warbler
An adult male Black-throated Blue Warbler.
Northern Parula
An acrobatic Northern Parula.
Blackburnian Warbler
Blackburnian Warblers continue their southerly trek.
American Redstart
An American Redstart.
Chestnut-sided Warbler
A Chestnut-sided Warbler feeding on Mile-a-minute Weed berries.
Cape May Warbler
A Cape May Warbler.
Adult Male Cape May Warbler
A handsome adult male Cape May Warbler.
Swainson's Thrush
A Swainson’s Thrush.
Scarlet Tanager
Scarlet Tanagers continue to work their way south through the Lower Susquehanna River Watershed.
Olive-sided Flycatcher
A composite image of an uncommon find, a large-headed Olive-sided Flycatcher seen perched atop a dead tree snag.
Philadelphia Vireo
A brief encounter with a Philadelphia Vireo, another uncommon species.
Blue-headed Vireo
A Blue-headed Vireo, typically the last of its genus to move south in the fall, put in a welcome appearance among the hundreds of migrants.
Ruby-throated Hummingbird
A favorite diurnal migrant, the Ruby-throated Hummingbird, was seen feeding on flowers that grew from the remains of garden waste dumped illegally along the mountain road last autumn.

Many of the observers at the Second Mountain Hawk Watch commented that this morning’s fallout was by far the best they had seen anywhere in the region during recent years.  Others believed it to be the best they had ever seen.  It was indeed less like a “wave” of migrants and more like a “tsunami”.  Choosing a good viewing location and being there at the right time can improve your chances of seeing a spectacle like this.  The good news is, it looks like another big flight is currently underway, so finding a forest edge on a ridgetop or along a utility right-of-way just might pay off for you early tomorrow morning.

Nocturnal migrating birds, a southwest-bound flight down the ridges of central Pennsylvania as indicated by Doppler radar between 10:30 and 11:30 PM EDT on September 11, 2024.  (NOAA/National Weather Service image)
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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)
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