It appears that spring has at last arrived. It’s time to have a look around!
Diurnal flights of northbound blackbirds including Common Grackles have been overspreading the Lower Susquehanna River Watershed since late February.And thawed soils are providing opportunities for nocturnal migrants like American Robins to search for earthworms and other invertebrates during their daytime layovers.Now that there is open water between here and the Great Lakes, flocks of waterfowl like these migratory Canada Geese are flying day and night on an excursion that will ultimately take them to their nesting grounds in the wilderness areas of Canada and Alaska.
Of the bird species that pass southbound through the lower Susquehanna valley during autumn, we can generally observe many of the surviving individuals as they return north during the spring. But there are numerous exceptions. One of them is Golden Eagles.
While the strong northwest winds of late autumn create ideal lift for migrating Golden Eagles along our linear ridges, they also tend to enhance the birds’ tendencies to “ridge hop” their way south, thus pushing many of them southeast from the main corridor of the eastern population’s route through the central Appalachian Mountains. Here in the lower Susquehanna region, we observe these vagabonds at our numerous hawk watches which happen to be located along the outer periphery of the birds’ primary flight path. It appears that a greater percentage of these wayward eagles tend to be younger, less-experienced birds than those seen passing hawk-counting stations in the central Appalachians. Lucky for us, we get to see more of the showy juvenile and immature Golden Eagles—at least during the fall season.
In the spring, southerly breezes and the urge to “ridge hop” in a northerly direction tend to concentrate Canada-bound migrating Golden Eagles along the northernmost ridges in their Appalachian flyway. To see them, we took a short drive up the Juniata River valley to the 90,000 acres of Rothrock State Forest and Tussey Mountain Hawk Watch. During our visit there earlier this week, gusty winds from the southwest brought us an opportunity to see the elusive northbound flights of some of the members of eastern North America’s population of Golden Eagles.
Tussey Mountain Hawk Watch is located along State Route 26 atop Tussey Mountain, just south of State College, Pennsylvania. Visitors can find ample parking at the Jo Hays Vista along the west side of the road on the crest of the ridge .Looking north from Jo Hays Vista to State College and the main campus of Penn State University. Bald Eagle Mountain is in the background and behind it lies Allegheny Front and Plateau.From the Jo Hays Vista parking area, follow the Mid State Trail (orange blazes) south along the ridgetop for about a half mile to the Tussey Mountain Hawk Watch lookout.The lookout at Tussey Mountain Hawk Watch is located within a utility right-of-way with talus slopes flanking the ridgetop clearing.An interpretive sign shows a statistical graphic describing the seasonal abundance of Golden Eagle sightings at the site. The peak time: late February through early April.Tussey Mountain is the only hawk-watching station in the lower Susquehanna region staffed by an official counter to collect data during the spring migration season. You can view the daily counts at hawkcount.org. You can contribute to them by visiting the hawk watch to help scan the skies.By late morning, a small flight of Golden Eagles had commenced. Most of the birds seen at Tussey Mountain are adult or near-adult birds with dark wing linings and slightly paler flight feathers. It’s a two-toned appearance similar to that of a Turkey Vulture and there is little if any variation in the length of the flight feathers. These birds are three years of age or older, are or soon will be sexually mature, and often travel in pairs separated by a minute or two of flight time.This Golden Eagle caught our attention with its longer central tail feathers and some longer secondary feathers in the wings that create a wavy appearance. As they get older, immature eagles should become more skilled as fliers, so each new set of flight feathers is usually shorter than those they’re replacing. Based upon the characters contributing to its ragged appearance, this bird is probably in the early months of its fourth or fifth calendar year of life.Common Ravens are forever vigilant around our regional hawk watches. They can sometimes help us find otherwise hard-to-spot migratory raptors in the bright, sunny skies.Ravens really like to harass younger birds like this second or third-year Golden Eagle.Older, more stoic raptors like this adult Bald Eagle spend less time contending with the antics of the persistent ravens.One of the final sightings of the day was this magnificent Golden Eagle. Look closely and you can see evidence of some molt completed last year in the outer tail feathers and the innermost primaries in the wings. On top, there were tawny bars on the wing coverts. This bird is probably just beginning its third calendar year of life and will start replacing many more flight feathers later this spring.
For more information on the region’s hawk watches and the birds you’ll see there, be certain to click the “Hawkwatchers Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page. And for a more detailed look at how to determine the age of Golden Eagles, particularly during the autumn migration, click the “Golden Eagle Aging Chart” tab at the top of this page.
Mid-November is our favorite time of year to visit Hawk Mountain Sanctuary on Blue Mountain/Kittatinny Ridge just to the east of the lower Susuquehanna valley near Kempton, Pennsylvania. By now, the huge crowds that come to see October’s world-famous raptor flights and spectacular fall foliage have dwindled to small groups of serious hawkwatchers and hardy trail enthusiasts. Join us as we drop in on the Keystone State’s most famous birding destination.
The entrance to Hawk Mountain Sanctuary is located at 1700 Hawk Mountain Road off PA Route 895 east of PA Route 61.Start your visit with a stop inside the refuge headquarters building where you’ll find raptor ecology and migration displays, a gift shop, and a window overlooking a busy bird-feeding station. Hawk Mountain is a non-profit organization that receives no taxpayer support and relies largely upon membership fees and donations for the majority of its operating expenses. Inside the headquarters building, you can pay dues and join on the spot.The native plant habitat includes a pond and a rain garden that collects stormwater from the roof of the headquarters building. There’s also a memorial fern garden named for the refuge’s first curator, Maurice Broun, author of a 1938 index to the ferns of North America.After a visit to the habitat garden, it’s time to make our way toward the lookouts.2024 marks the 90th anniversary of the founding of Hawk Mountain Sanctuary. We stopped at the trail crossing along the mountain road to admire this newly erected sign.Trail fees are collected to support the sanctuary’s operations and maintain its 2,600 acres. Members enter free.Interpretive signs and trail information are provided throughout the refuge, particularly along the mile-long climb to the North Lookout.Aside from the route to the lookouts (along which sturdy shoes and good balance are a must), many of the sanctuary’s hiking trails require special equipment and preparations. Be certain to follow the posted guidelines.The scope of Hawk Mountain’s educational mission includes topics ranging from local Appalachian natural history to global raptor conservation.Just a few hundred yards from the entrance gate, South Lookout provides a panoramic view of the “River of Rocks” talus outcrop and beyond. On days with southerly winds, autumn raptor flights are sometimes enumerated from this location.Hawk Mountain’s “classroom in the sky”, the North Lookout, hosts school and scout groups learning raptor identification and ecology. It’s the sanctuary’s primary location for counting thousands of migrating birds of prey each fall.Students quickly learn to identify distant Turkey Vultures by their upturned wings held in a dihedral posture and by their rocking motion in flight.After the pupils depart for the day, there are but few observers remaining to find and count passing hawks and eagles during mid-November.While sitting quietly among the boulders of North Lookout waiting for the next bird to come along, one can be treated to a visit by one or more of a local population of Southern Red-backed Voles (Clethrionomys gapperi).Red-tailed Hawks remain common among the flights of mid-November migrants.And it happens to be an ideal time to see Red-shouldered Hawks on the move.While you were busy looking up, the Southern Red-backed Vole was at your feet scarfing up the crumbs from your sandwich. When not availed of our leftovers, its diet includes seeds, various plant parts, and subterranean fungi.Playful groups of Common Ravens often provide comic relief during interludes in the parade of migrants.Don’t look now, but your friend the vole has scurried away and a Northern Short-tailed Shrew (Blarina brevicauda) has arrived from beneath the rocks to finish the remnants of your lunch. On the rocky outcrops atop the ridges of southeastern Pennsylvania, these mammals are often found in close company; Red-backed Voles traveling through the burrows and runways created by Northern Short-tailed Shrews instead of excavating their own. Unlike the vegetarian voles, shrews are classified as insectivores, behaving mostly as carnivorous mammals. Equipped with salivary venom, they can consume prey as large as other similarly sized vertebrates, including small voles.Flights of Bald Eagles thrill visitors on North Lookout throughout November.But late-season visitors really want to see a Golden Eagle. On a chilly day with gusty northwest winds, few are disappointed.We got very lucky during a recent day on North Lookout, spotting this rarity, a hatch-year/juvenile American Goshawk (Accipiter atricapillus), a species which, in 2023, was split from the Northern Goshawk (Accipiter gentilis), a species which was simultaneously assigned the new common name Eurasian Goshawk. Even more recently, within the past several weeks, the genus name Astur has replaced Accipiter for the goshawks, now formally known as the the American Goshawk (Astur atricapillus) and the Eurasian Goshawk (Astur gentilis). The new classification includes Cooper’s Hawk in the genus Astur, while the Sharp-shinned Hawk remains in the genus Accipiter.A November specialty, a hatch-year/juvenile American Goshawk (Astur atricapillus) passes the North Lookout. During this century, the drop in American Goshawk numbers has been precipitous. Most eastern hawk-counting stations see fewer than four or five goshawks during their entire fall season. Many no longer see them at all.Here and gone in a jiffy, a brief but memorable look at a hatch-year/juvenile American Goshawk.
If the cold of mid-November doesn’t cramp your style, and if you’d like to seize your best opportunity for a much-coveted sighting of one or more of the late-season specialties, then now is the time to visit Hawk Mountain Sanctuary. Bring a cushion upon which to sit, dress in layers, pack a lunch, and plan to spend the day. You could be rewarded with memorable views of the seldom-encountered species some people spend years of their lives hoping to see.
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.
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!The dense understory of this forest on Blue Mountain consists almost exclusively of Witch-hazel (Hamamelis virginiana).Witch-hazel is unique among our native flowering shrubs; it blooms in autumn.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.A Pearl Crescent.A Variegated Fritillary.A Painted Lady.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.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 Sparrows are southbound and easily observed right now. Many will remain along our brushy forest edges for winter.Another native sparrow, the familiar Dark-eyed Junco, is now arriving.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.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.You may see Eastern Bluebirds year-round in the lower Susquehanna valley, but many are migratory. A southbound push is currently transiting our area.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.In addition to spectacular foliage, you stand a good chance of seeing an inquisitive Common Raven……or a migrating Red-tailed Hawk that gives you a good scream as it passes by……or a majestic Bald Eagle.You may even double your fun by seeing two Common Ravens……or a couple of migrating Red-tailed Hawks……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.
With nearly all of the Neotropical migrants including Broad-winged Hawks gone for the year, observers and counters at eastern hawk watches are busy tallying numbers of the more hardy species of diurnal raptors and other birds. The majority of species now coming through will spend the winter months in temperate and sub-tropical areas of the southern United States and Mexico.
Here is a quick look at the raptors seen this week at two regional counting stations: Kiptopeke Hawk Watch near Cape Charles, Virginia, and Second Mountain Hawk Watch at Fort Indiantown Gap, Pennsylvania.
The hawk-watching platform at Kiptopeke State Park is located along Chesapeake Bay near the southern tip of Delmarva Peninsula. In autumn, thousands of raptors and other birds migrate through the Atlantic Coastal Plain Province. Those that follow the shorelines south frequently concentrate in spectacular numbers before crossing the mouths of the bays they encounter. This phenomenon makes both Cape May, New Jersey, on Delaware Bay and Kiptopeke, Virginia, on Chesapeake Bay exceptional places to experience fall flights of migrating birds.A Sharp-shinned Hawk is counted as it swoops by the owl decoy at Second Mountain Hawk Watch at Fort Indiantown Gap Military Reservation. Migrating raptors save energy by riding updrafts of air created by winds blowing against the slopes of the mountainsides in the Ridge and Valley Province.A Sharp-shinned Hawk passes the lookout at Second Mountain Hawk Watch. “Sharp-shins” are currently the most numerous migrants both on the coast and at inland counting stations.A Sharp-shinned Hawk nearly passes observers unnoticed as it skims the treetops.A Sharp-shinned Hawk eyes up an owl decoy. Under cover of darkness, nocturnal owls could rather easily prey upon young and small adult hawks and falcons, both on the nest or at roost. Accordingly, many diurnal raptors instinctively harass owls to drive them from their presence. An owl decoy at the lookout helps attract migrating birds for a closer look.An adult Cooper’s Hawk flaps its way past a counting station. Like the similar Sharp-shinned Hawk, the larger Cooper’s Hawk is a member of the genus Accipiter. As a proportion of the annual fall Accipiter flight, the Cooper’s Hawk is more numerous at coastal hawk watches than at inland sites. (Editor’s Update: As of autumn, 2024, the Cooper’s Hawk and the American Goshawk have been placed in the genus Astur. The Sharp-shinned Hawk remains in the genus Accipiter. Though the Cooper’s Hawk and Sharp-shinned Hawk are oft times confused by observers due to their like appearance, it turns out that the two are not as closely related as originally believed. Neither is an offshoot of the other, nor do they descend from an immediate common ancestor. Their resemblance may instead be a case of convergent evolution, most readily characterized by acquisition of similar physical traits due to shared demands for survival within their environment.)The majority of Osprey migrate along the coast, but a few are still being seen at inland hawk watches.Bald Eagles are commonly seen at both coastal and inland lookouts. Their movements continue well into late fall.A Northern Harrier illuminated by a setting sun. Northern Harriers are often still flying when many other species have gone to roost for the day.An adult male Northern Harrier, the “gray ghost”, flying in misty weather, at a time when few other birds were in the air.The American Kestrel, like our other falcons, is seen in greatest concentrations at coastal counting stations. It is our most numerous falcon.The Merlin provides only a brief observation opportunity as it passes the lookout. These falcons are dark, speedy, and easily missed as they fly by.While moving south, Merlins often accompany flights of migrating Tree Swallows, a potential food source.A Merlin consumes a dragonfly. Eating is no reason to stop moving.The “Tundra Peregrine” is an arctic-breeding Peregrine Falcon that travels a distance of over 6,000 miles to southern South America for winter. It is strictly a migratory species in our region with numbers peaking during the first two weeks of October each year. These strong fliers have little need for the updrafts from mountain ridges, inland birds often observed flying in a north to south direction. The majority of “Tundra Peregrines” are observed following coastlines, with some migrating offshore to make landfall at points as far south as Florida and the Caribbean islands before continuing across water again to reach the northern shores of Central and South America. This “Tundra Peregrine” is a juvenile bird on its first southbound trip.
During coming days, fewer and fewer of these birds will be counted at our local hawk watches. Soon, the larger raptors—Red-tailed Hawks, Red-shouldered Hawks, and Golden Eagles—will be thrilling observers. Cooler weather will bring several flights of these spectacular species. Why not plan a visit to a lookout near you? Click on the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page for site information and a photo guide to identification. See you at the hawk watch!
It’s not all hawks at the hawk watch. Even the coastal sites are now seeing fun birds like the playful Common Raven on a regular basis.Coastal locations are renowned places to see migrating songbirds in places outside of their typical habitat. Here a flock of Eastern Meadowlarks has set down in the top of a Loblolly Pine (Pinus taeda) in downtown Cape Charles, Virginia, not far from Kiptopeke Hawk Watch.
Resembling an overgrown crow with a wedge-shaped tail, the Common Raven is an oft times comical corvid; this one twisting its head to have a gander at observers on a ridgetop hawk-counting lookout.
Can it be that time already? Most Neotropical birds have passed through the Lower Susquehanna River Watershed on their way south and the hardier species that will spend our winter in the more temperate climes of the eastern United States are beginning to arrive.
Here’s a gallery of sightings from recent days…
During the past two weeks, thousands of Broad-winged Hawks, including this adult bird, crossed the skies of the lower Susquehanna valley on their way to Central and South America for our winter.A juvenile Broad-winged Hawk passes into the sunset during its first autumn migration.Blackpoll Warblers are among the last of the Neotropical species to transit the region. They’ll continue to be seen locally through at least early October.Blue-headed Vireos are the October vireo during the fall, the other species having already continued toward tropical forests for a winter vacation.The lower Susquehanna region lies just on the northern edge of the wintering range of the Blue-gray Gnatcatcher, a species found nesting locally among treetops in deciduous woods. Look for their numbers to swell in coming days as birds from further north begin rolling through the region on their way south.Sharp-shinned Hawks delight visitors at ridgetop hawk watches during breezy late-September and early-October days. They allow closer observation than high-flying Broad-winged Hawks due to their habit of cruising just above the treetops while migrating.A Sharp-shinned Hawk glides over a lookout.Late September/early October is falcon time at area hawk-counting stations, the Peregrine Falcon often being the most anticipated species.Pale “Tundra Peregrines”, a subspecies that nests in the arctic, are strictly migratory birds in the Mid-Atlantic States. They are presently passing through on their way to South America. Like Neotropical songbirds, their long flights provide them with the luxury of never experiencing a winter season.This Carolina Saddlebags and other migratory dragonflies, which normally leave the area by mid-September, are still lingering in the lower Susquehanna region, much to the pleasure of the falcons that feed upon them.An male American Kestrel in pursuit of dragonflies found swarming around the lookout at Second Mountain Hawk Watch in Lebanon County, Pennsylvania.A male American Kestrel stooping on a dragonfly.Osprey will be among the birds of prey passing hawk watch sites during the coming two weeks. The first week of October often provides the best opportunity for seeing the maximum variety of raptors at a given site. On a good day, a dozen species are possible.Seeing cinnamon-colored juvenile Northern Harriers is symbolic of the October migration flights.Bald Eagles always thrill the crowd.In addition to raptors, resident Common Ravens are regularly sighted by observers at hawk watches and elsewhere during the fall season.Hawk-counting stations sometimes log movements of Red-bellied Woodpeckers during late September and early October. This species has extended its range into the Lower Susquehanna River Watershed only during the past one hundred years, making these seasonal migration movements a recent local phenomenon.Blue Jays are currently on the move with breeding birds from the forests of Canada and the northern United States moving south. Hundreds can be seen passing a given observation point during an ideal morning.Blue Jays find a pile of peanuts to be an irresistible treat. Provide the unsalted variety and watch the show!
Be sure to click on these tabs at the top of this page to find image guides to help you identify the dragonflies, birds, and raptors you see in the Lower Susquehanna River Watershed…
Damselflies and Dragonflies
Birds of Conewago Falls
Hawkwatcher’s Helper: Identifying Bald Eagles and other Raptors
Why would otherwise sensible people perch themselves atop a rocky outcrop on a Pennsylvania mountaintop for ten hours on a windy bone-numbing bitter cold and sometimes snowy November day? To watch migrating raptors of course.
November is the time when big hawks and eagles migrate through and into the lower Susquehanna valley. And big birds rely on big wind to create updrafts and an easy ride along the region’s many ridges. The most observable flights often accompany the arrival of cold air surging across the Appalachian Mountains from the northwest. These conditions can propel season-high numbers of several of the largest species of raptors past hawk-counting sites.
Observers brave howling winds on the Waggoner’s Gap lookout to census migrating late-season raptors.
Earlier this week, two windy days followed the passage of a cold front to usher-in spectacular hawk and eagle flights at the the Waggoner’s Gap Hawk Watch station on Blue Mountain north of Carlisle, Pennsylvania. Steady 30 M.P.H. winds from the northwest on Monday, November 2, gusted to 50 M.P.H. at times. Early that morning, two Rough-legged Hawks, rarities at eastern hawk watches, were seen. They and two American Goshawks (Astur atricapillus) provided a preview of the memorable sightings to come. Two dozen Golden Eagles migrated past the lookout that day. Then on November 3, thirty Golden Eagles were tallied, despite west winds at speeds not exceeding half those of the day before.
Here are some of the late-season raptors seen by hardy observers at Waggoner’s Gap on Monday and Tuesday, November 2 & 3.
In November, Red-tailed Hawks are the most common migratory raptor counted at hawk watch stations in the Susquehanna region.An uncommon bird, a juvenile American Goshawk, passes the Waggoner’s Gap lookout.An adult Golden Eagle circles on an updraft along the north face of Blue Mountain to gain altitude before continuing on its journey.The plumage of juvenile and immature Golden Eagles often creates a sensation among crowds at a lookout. Golden Eagles don’t attain a full set of adult feathers until their sixth year. This individual is probably a juvenile, also known as a hatch-year or first-year bird. At most, it could be in its second year. Click the “Golden Eagle Aging Chart” tab on this page to learn more about these uncommon migrants and their molt sequences as they mature.The gilded head feathers of a Golden Eagle glisten in the afternoon sun.An adult Golden Eagle passing Waggoner’s Gap. The population known as “Eastern Golden Eagles” winters in the Appalachian Mountains and, with increasing frequency, on the Piedmont and Atlantic Coastal Plain Provinces of the eastern United States, where it often subsists as a scavenger.Another first-year (juvenile) or second-year Golden Eagle.A local Red-tailed Hawk (top left) trying to bully a migrating Golden Eagle. A dangerous business indeed.Through December, Bald Eagles, presently the more common of our eagle species, are regular migrants at Waggoner’s Gap and other Susquehanna valley hawk watch sites.Red-shouldered Hawks are reliable early November migrants.An adult Red-shouldered Hawk from above.And an adult Red-shouldered Hawk from below.Though their numbers peak in early October, Sharp-shinned Hawks, particularly adults like this one, continue to be seen through early November.A Northern Harrier on the glide path overhead.Merlins, like other falcons, are more apt to be seen in late September and October, but a few trickle through in November.
While visiting a hawk watch, one will certainly have the opportunity to see other birds too.
Common Ravens are fascinating birds and regular visitors to the airspace around hawk watches. Most are residents, but there appears to be some seasonal movement, particularly among younger birds.Most people think of Common Loons as birds of northern lakes. But loons spend their winters in the ocean surf, and to get there they fly in loose flocks over the Lower Susquehanna River Watershed each spring and fall. They are regularly seen by observers at hawk watches.Like ducks, geese, and swans, migrating Double-crested Cormorants assemble into aerodynamic V-shaped flocks to conserve energy.Pine Siskins continue their invasion from the north. Dozens of small flocks numbering 10 to 20 birds each continue to be seen and/or heard daily at Waggoner’s Gap. A flock of Evening Grosbeaks (Coccothraustes vesperitinus), another irruptive species of “winter finch”, was seen there on November 3.
As a finale of sorts, near the close of the day on November 3, two Golden Eagles sailed past the north side of the Waggoner’s Gap lookout, one possessing what appeared to be a tracking transmitter on its back. An effort was commenced by the official count staff to report the sighting to the entity monitoring the bird—to track down the tracker, so to speak.
A Golden Eagle with a backpack transmitter passing Waggoner’s Gap Hawk Watch at 3:39 P.M. Eastern Standard Time on November 3, 2020.
To see the count reports from Waggoner’s Gap and other hawk watches throughout North America, be certain to visit hawkcount.org
A couple of inches of rain this week caused a small increase in the flow of the river, just a burp, nothing major. This higher water coincided with some breezy days that kicked up some chop on the open waters of the Susquehanna upstream of Conewago Falls. Apparently it was just enough turbulence to uproot some aquatic plants and send them floating into the falls.
Piled against and upon the upstream side of many of the Pothole Rocks were thousands of two to three feet-long flat ribbon-like opaque green leaves of Tapegrass, also called Wild Celery, but better known as American Eelgrass (Vallisneria americana). Some leaves were still attached to a short set of clustered roots. It appears that most of the plants broke free from creeping rootstock along the edge of one of this species’ spreading masses which happened to thrive during the second half of the summer. You’ll recall that persistent high water through much of the growing season kept aquatic plants beneath a blanket of muddy current. The American Eelgrass colonies from which these specimens originated must have grown vigorously during the favorable conditions in the month of August. A few plants bore the long thread-like pistillate flower stems with a fruit cluster still intact. During the recent few weeks, there have been mats of American Eelgrass visible, the tops of their leaves floating on the shallow river surface, near the east and west shorelines of the Susquehanna where it begins its pass through the Gettysburg Basin near the Pennsylvania Turnpike bridge at Highspire. This location is a probable source of the plants found in the falls today.
Uprooted American Eelgrass floating into the Pothole Rocks under the power of a north wind. Note the white thread-like pistillate flower stem to the left and the small rooted specimen to the upper right. The latter is likely a plant from the creeping rootstock on the edge of a colony. As a native aquatic species, American Eelgrass is a critical link in the Susquehanna River and Chesapeake Bay food chain. Its decimation by pollution during the twentieth century led to migration pattern alterations and severe population losses for the Canvasback (Aythya valisineria) duck.American Eelgrass, a very small specimen, found growing in a low-lying Pothole Rock alongside the accumulations of freshly arriving material from upstream. Note that the creeping rootstock has leaves growing from at least three nodes on this plant. Eelgrass dislocations are regular occurrences which sometimes begin new colonies, like the small one seen here in this Diabase Pothole Rock Microhabitat.
The cool breeze from the north was a perfect fit for today’s migration count. Nocturnal migrants settling down for the day in the Riparian Woodlands at sunrise included more than a dozen warblers and some Gray Catbirds (Dumetella carolinensis). Diurnal migration was underway shortly thereafter.
A moderate flight of nocturnal migrants is indicated around NEXRAD sites in the northeastern states at 3:18 AM EDT. The outer rain bands of Hurricane Irma can be seen approaching the Florida Keys as the storm closes in on the peninsula. (NOAA/National Weather Service image)
Four Bald Eagles were counted as migrants this morning. Based on plumage, two were first-year eagles (Juvenile) seen up high and flying the river downstream, one was a second-year bird (Basic I) with a jagged-looking wing molt, and a third was probably a fourth year (Basic III) eagle looking much like an adult with the exception of a black terminal band on the tail. These birds were the only ones which could safely be differentiated from the seven or more Bald Eagles of varying ages found within the past few weeks to be lingering at Conewago Falls. There were as many as a dozen eagles which appeared to be moving through the falls area that may have been migrating, but the four counted were the only ones readily separable from the locals.
Red-tailed Hawks (Buteo jamaicensis) were observed riding the wind to journey not on a course following the river, but flying across it and riding the updraft on the York Haven Diabase ridge from northeast to southwest.
Bank Swallows (Riparia riparia) seem to have moved on. None were discovered among the swarms of other species today.
Ruby-throated Hummingbirds, Caspian Terns, Cedar Waxwings (Bombycilla cedrorum), and Chimney Swifts (Chaetura pelagica) were migrating today, as were Monarch butterflies.
Not migrating, but always fun to have around, all four wise guys were here today. I’m referring to the four members of the Corvid family regularly found in the Mid-Atlantic states: Blue Jay (Cyanocitta cristata), American Crow (Corvus brachyrhynchos), Fish Crow (Corvus ossifragus), and Common Raven (Corvus corax).
It looks like a big Blue Jay, but it’s not. This Belted Kingfisher (Megaceryle alcyon) takes a break after flying around the falls trying to shake a marauding Ruby-throated Hummingbird off its tail.CLICK ON THE LOGO FOR TODAY’S MIGRATION COUNT TOTALS
SOURCES
Klots, Elsie B. 1966. The New Field Book of Freshwater Life. G. P. Putnam’s Sons. New York, NY.
