Few places in North America offer an observer the opportunity to stand in one spot and, with a single 180° sweep of a pair of binoculars, count 165 Bald Eagles. Sounds impossible, but we experienced just that earlier today along the Susquehanna River below Conowingo Dam at Fisherman’s Park off U.S. Route 1 west of Rising Sun, Maryland. More than 200 eagles are there right now, so you really ought to think about visiting to see it for yourself. If you can’t make the trip, or if you need a little more convincing, we’ve put together a big collection of photographs for you to enjoy. Have a look…
In late November and December, hundreds of eagle watchers and photographers travel to Fisherman’s Park along the west shore of the Susquehanna River below Conowingo Dam/U.S. Route 1 to witness the largest annual gathering of our national symbol on the east coast.The park provides facilities for viewing right on the waterfront and is maintained by the operator of the hydroelectric dam, Constellation Energy.From the riverside viewing area, we counted 165 Bald Eagles on the rocks along the east shore of the river and on the electric transmission line trestles. That count didn’t include scores of additional birds obstructed from our view along the near shore downstream and along the east shore behind the mid-river island below the dam.A closeup of some of the 165 Bald Eagles we counted. Many of these birds, particularly the adults, are eagles that nest to our north and are here for a short winter stay. Local breeding pairs, including several with nests along the river below the dam, are already courting, copulating, and defending territories; the latter no easy task for the Conowingo birds facing all these visitors.The concentrations of Bald Eagles at Conowingo Dam sometimes provide an excellent opportunity to study the plumage of birds from the various age classes. Today’s assemblage put on a clinic.A nice, neat hatch-year/juvenile Bald Eagle in its first full set of feathers shows no molt.This bird was an unusual find, a hatch-year/juvenile Bald Eagle with early signs of molt. There’s even a new secondary feather visible in the gap on the left wing.The wings of a second-year/basic I immature Bald Eagle have a ragged appearance created by the long juvenile secondary feathers that have yet to be dropped.Another second-year/basic I immature Bald Eagle showing some longer juvenile secondaries on each wing.A third-year/basic II immature Bald Eagle showing a neater, cleaner trailing edge of the wings with no more long juvenile flight feathers. The wide dark stripe through the face gives the bird an osprey-like appearance. The bill color is usually more noticeably yellow than a second-year bird, but both can have extensive white in the belly feathers and elsewhere on the underside and shoulders.Third-year/basic II immature Bald Eagles exhibiting aggressive behavior.A fourth-year/basic III immature Bald Eagle with a black-bordered tail, yellow bill, and a thin dark line through the eye. Birds this age are mostly dark below, but often retain some white feathers which present a spotted appearance.The water passing through the dam not only attracts eagles, but other birds as well. Many, including these gulls, are looking for fish stunned or disoriented by their trip through the turbines, gates, or spillways.More than one hundred Ring-billed Gulls are currently being seen at Conowingo Dam.We saw a few American Herring Gulls as well.A juvenile American Herring Gull.Probably a hundred Black Vultures or more were in the vicinity.A Black Vulture by the park’s riverside lookout.We heard this Peregrine Falcon as it tangled with several eagles behind us before it quickly darted away across the top of the powerhouse and dam.Double-crested Cormorants were diving persistently in search of unwary prey.A composite image of a Double-crested Cormorant gulping down a Gizzard Shad.But these vigilant eagle watchers and photographers don’t come to Conowingo Dam and Fisherman’s Park to see Bald Eagles of various age classes flying around. Nor do they come to see the other amazing birds attracted to the waters passing through the dam.And they don’t even come to see some pretty good aerial fights among the numerous eagles congregated in the river gorge.They come specifically to see and photograph Bald Eagles swooping in to grab a fish. That’s their objective and they’re serious about it!A probable fourth-year/basic III immature Bald Eagle with a Gizzard Shad.An immature Bald Eagle swoops in to grab a fish.An immature Bald Eagle stretches its wings forward with a deep stroke to lift a fish from the Susquehanna.A Bald Eagle, possibly a fifth-year/basic IV bird, carrying away a freshly caught Gizzard Shad.An adult Bald Eagle comes in for the grab.An adult Bald Eagle comes away with a Gizzard Shad.Now the hard part, finding a place to eat its catch in peace.
If you go to Fisherman’s Park, time your visit for when the light is at its best—late morning through early afternoon. Don’t forget, it’s very cold down along the river, so dress appropriately. And finally, visit on a weekday if you can. The parking area can fill to capacity during the weekend and you may be turned away.
Don’t wait. The eagles visiting the Susquehanna at Conowingo Dam could get pushed further south by rough winter weather. Then again, adult pairs may take advantage of milder conditions to begin returning north early to nest.
The arrival of arctic air and sub-freezing temperatures reminds us that winter is soon here. But for this Bald Eagle, preparations for spring are already underway. Pairs nesting in the lower Susquehanna valley have begun courtship and many females will be incubating eggs in January. By March, parents will be bringing food to hungry nestlings. The timing of the Bald Eagle’s breeding cycle provides the best chances for an adequate supply of provisions for their young. Their peak demand for food coincides with the arrival of thousands of migrating waterfowl and other birds and with the migration of suckers and other fish on local streams. From these massive legions of migrants, adult eagles cull the weak and vulnerable, or scavenge the carcasses of those that have already perished. Bald Eagles in Florida and elsewhere in the south have a nesting schedule with similar benefits; their young are hatching now to fed by parents taking advantage of the immense numbers of waterfowl and other birds presently arriving to spend the winter there.
If you provide supplemental foods for the birds visiting your garden sanctuary, we don’t need to tell you how expensive those provisions have become. It can be quite frustrating when the majority of these pricey supplies get gobbled up by the chunky squirrels that dominate your feeding station and leave hungry birds with nothing but the tiny little scraps.
Here at susquehannawildlife.net headquarters, we like to feed whole peanuts in the shell to the resident and migratory native birds. But placed out in the open on a stump or a tray, or even within a hopper feeder, peanuts are quickly carried away and cached for latter use by squirrels and jays. The chickadees, titmice, nuthatches, wrens, and woodpeckers that could really use the extra food to maintain their body fat through the winter get nothing but leftovers.
It’s not unusual for squirrels and jays to scarf up and carry away 90% or more of the expensive peanuts placed at your feeding station. The dozen or more other species of native birds that will partake of this offering get the leftovers or nothing at all.
We’ve discovered a solution that, for us, saves money and more efficiently feeds the native species of birds that stop by our oasis. We’ve been using inexpensive ($6-$8) wire mesh tube feeders intended for suet nuggets to serve whole peanuts in the shell to our guests. As long as they can’t knock the feeders to the ground, squirrels have failed to raid the contents. Like other birds, Blue Jays can still peck away to remove the peanuts from their shells and eat them on the spot, but they can no longer haul off a whole feeder load at a time. Each must carefully crack the shell and remove an individual peanut or portion thereof for immediate consumption. The empty shells remain mostly in the tubes and don’t make a mess. Pesky hoards of non-native European Starlings sometimes visit, but soon become frustrated because their bills aren’t adapted for cracking the hardened peanut husks; they grab any loose morsels they can get, then move along.
We assemble these suet nugget feeders without installing the included perches. We fill them with UNSALTED peanuts in the shell, then hang them from stiff wire hooks beneath the larger horizontal limbs on some of our trees. About every 5 to 10 days, we take them down to remove empty shells, clean the feeder, and add peanuts. A 2-pound bag that would disappear within hours if freely accessible to squirrels now fills 3 feeders or more and nourishes our native birds for a week or longer.
The list of native birds visiting our peanut feeders includes:
Downy Woodpecker
Hairy Woodpecker
Red-bellied Woodpecker
Northern Flicker
Yellow-bellied Sapsucker
Blue Jay
Carolina Chickadee
Black-capped Chickadee
Tufted Titmouse
White-breasted Nuthatch
Red-breasted Nuthatch
Carolina Wren
The most recent addition to the list of birds feasting on peanuts from our wire mesh tube feeders was this Yellow-bellied Sapsucker that visited yesterday.
So don’t pay hard-earned cash to feed nothing but leftovers to your intended guests, give wire mesh tube feeders and whole peanuts in the shell a try. The colorful native birds will thank you with their presence.
A welcome visitor, a Yellow-bellied Sapsucker stopping by for dinner……and varying its diet by finding small insects among the bark of some of our larger trees.
Late this afternoon, this rainbow accompanied passage of a brief rain shower over the Stony Creek Valley and Saint Anthony’s Wilderness near Rausch’s Gap in Lebanon County, Pennsylvania.
There’s now a sense of urgency because for the Eastern Chipmunk, the opportunities to gather and store nuts, seeds, and acorns are slipping away. The time has arrived for retreat to its burrow where, because it stores no body fat for winter, this member of the squirrel family (Sciuridae) relies upon its cache of provisions for snacking between periods of extended slumber during the coldest months of the year.
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.
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.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.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.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.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.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.
This Golden Eagle was seen tangling with a Common Raven as it passed a lower Susquehanna valley hawk-counting station earlier today.The two traded barbs until continuing down the ridge to the southwest.A composite image shows a close-up view of the migrating raptor. It has the showy white tail with a black terminal band that Golden Eagle enthusiasts regard as particularly spectacular on these majestic birds when they’re young. But where are the conspicuous white patches in the wings? And just how old is this eagle? We’ll give you a hint; if you note the appropriate field marks, this is actually a classic example of a bird its age. To learn the critical field marks and to determine the age of this bird, be certain to click the “Golden Eagle Aging Chart” tab at the top of this page.
Earlier today, observers at Second Mountain Hawk Watch at Fort Indiantown Gap in Lebanon County, Pennsylvania, were treated to excellent looks at a migrating “Bartelemyi Golden Eagle”, a rare variant of the species recognized by white scapulars that mimic a pair of epaulets on the shoulders.
The “Barthelemyi Golden Eagle” variant is recognized by the pair of white scapulars that create epaulets on its shoulders. Molt in the primaries indicates that this is a second-year (Basic I) bird.This is the third “Barthelemyi Golden Eagle” sighting in the past eight years at Second Mountain. The first was on October 21, 2017, and the second was less than a year ago on December 6, 2023.
For more information on the “Barthelemyi Golden Eagle” sightings at Second Mountain, see our post from December 6, 2023.
Remember, it ain’t over ’til it’s over, there are still more eagles and other raptors on the way! And if you’d like to catch a glimpse of one of these rare “Barthelemyi Golden Eagles”…well, you know where you oughta be.
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.
With low relative humidity, gusty daytime breezes, and little or no rain in the forecast, many counties and local municipalities in the lower Susquehanna basin have enacted bans on open burning to prevent accidental wildfires. With these dangerous conditions prevailing, you know enough not to burn trash and leaves, or to carelessly discard ashes or smoking materials. And you’re smart enough to keep close watch on fires used for cooking and to keep them within approved enclosures such as a grill with a lid. But have you thought of eliminating another common form of ignition, this one originating from your car or truck? Your motor vehicle’s catalytic converter is hot enough to ignite dry leaves, grasses, and crop residues like corn shocks upon contact, so be extra careful where you park. Be certain that your pollution control device remains free and clear of combustibles!
During the summer, the Lesser Angle-winged Katydid has little difficulty hiding among the lush green foliage of hardwood trees. Oft times, the only sign of its presence is its call, a series of short rapid rattles, “ttt—-tttt—-ttt”, issued with a second or two of silence between each rattle. The call is often part of the nocturnal chorus it shares with other species of katydids on warm evenings. Frost and freeze usually bring these annual breeding rituals to end. But during our current resurgence of warm autumn weather, we found this hardy survivor in a forest clearing where it has little hope of escaping notice among bare trees and earth-tone fallen leaves. As the afternoon temperature soared into the upper seventies, it further revealed its presence by striking up its tell-tale mating call, “ttt—-tttt—-ttt.”
As we enter November, migratory raptor flights through the Lower Susquehanna River Watershed transition to the bigger birds. Whether you’re on the river, on a mountain, or just outside your humble abode, persistent alertness to soaring avians can yield rewarding views of a number of late-season specialties.
Red-tailed Hawks dominate the southbound raptor flights in November.Juvenile (hatch-year) Red-tailed Hawks are generally less wary and more inquisitive than the more experienced adult birds. Their curiosity frequently gets them into trouble, particularly when they try to hunt small rodents in traffic along busy roadways.Far fewer in number are migratory Red-shouldered Hawks. In our region, these denizens of bottomland forests more commonly migrate along the southern edge of the Piedmont and through the upper Atlantic Coastal Plain.A southbound hatch-year (juvenile) Red-shouldered Hawk.Mixed-race Peregrine Falcons, the descendants of birds reintroduced into the Mid-Atlantic States during the late twentieth century, often roam our region during the late-fall and winter months before settling into their nesting territories with the approach of spring. We spotted this one along a local ridge, but you may be more likely to see them in the city or near a bridge or dam on the river.As this adult peregrine passed the lookout, we noted its full crop. A sign it just completed a successful hunt.
A visit to a ridgetop on a breezy day—particularly after passage of a cold front—may give you the chance to see numerous eagles as well.
A second-year (Basic I) Bald Eagle barrel rolls while pursuing an adult Bald Eagle.
This afternoon, we got lucky and were treated to a bit of an aging clinic presented by the Bald Eagles we observed and photographed. Careful determination of the age classes of raptors counted by hawkwatchers can provide an early warning of problems in the ecosystems that support populations of these top-of-the-food-chain predators. For example: during the 1950s and early 1960s, a progressively lower percentage of juvenile and other non-adult age classes among the Bald Eagles being observed forewarned of the dangers of dichlorodiphenyltrichloroethane (DDT) pesticide in the environment. The principle effect of accumulations of the DDT toxins in eagles, Ospreys, Peregrine Falcons, and other predatory birds that consumed waterfowl and/or fish was to thin their eggs shells. The result was widespread brood failure and a near total loss of new generations of offspring. Eventually, nearly all Bald Eagles being seen in areas impacted by DDT were progressively older adults, most of which failed as nesting pairs. As the adult birds began dying off, the Bald Eagle population dwindled to numbers that raised fears of the species’ extinction. Implementation of the DDT cancellation order and the Clean Water Act in 1972, and the Endangered Species Act in 1973, helped save the Bald Eagle. But our regional “Eastern Peregrine Falcon”, a bird with a shorter life span than the Bald Eagle, was unable to endure the years of DDT use, dioxin pollution, and illegal hunting and egg collecting. Its population is gone.
A hatch-year (juvenile) Bald Eagle is typically dark headed and in a fresh set of juvenile flight feathers that exhibit no signs of molt. If the reproduction season and the months that followed were favorable for this year’s brood of new eagles, there should be nearly as many hatch-year birds as there are adults in an overall population.By November, second-year (Basic I) Bald Eagles are replacing many of their flight feathers and often show ragged trailing edges in the wings due to the retention of some of the well-worn and notably longer juvenile feathers. Varying amounts of white mottling are visible on the breast, belly, and underwing coverts. Due to mortality, there are usually fewer second-year Bald Eagles than there are hatch-year or adult birds.Another example of a second-year (Basic I) Bald Eagle.Third-year (Basic II) Bald Eagles show more yellow in the bill and an “osprey face”, a white head with a wide dark line through the eye. Most of the juvenile flight feathers have been replaced, so the wing edges appear more uniform. Like the second-year eagles, there is a varying amount of white in the breast, belly, and underwing coverts. In an overall population of eagles, birds in this age class are usually less common than those that are younger or those that are adults.Composite image of Bald Eagles in typical November plumage during their first three years. To see more images like this, be certain to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page.A fourth year (Basic III) Bald Eagle will often be seen with a black-bordered tail and a thin dark line through the eye. In some birds, traces of these traits can linger into the fifth year and beyond. These plumage types are usually the least frequently observed among an overall population of Bald Eagles. (Note: In these older birds, there develops significant variation in the timing of feather molt. In rare cases, fourth-year Bald Eagles may show minimal dark color in the tail or eye line and may appear to be in near definitive adult plumage.)A possible fifth-year (Basic IV) Bald Eagle.Adult Bald Eagles in definitive plumage. Birds in this plumage class are often the most frequently observed because the group includes all eagles five or six years of age and older.
While the Bald Eagles are still stealing the show, cold and gusty weather should bring an increasing number of Golden Eagles our way during the remainder of the month. Some are already trickling through…
This “before-third-year” Golden Eagle shows no visible signs of molt in its juvenile (hatch-year) plumage, but a look at the upperwing coverts is needed to properly age the bird. To learn more about the molt sequence in Golden Eagles, be sure to click the “Golden Eagle Aging Chart” tab at the top of this page.A “before-third-year” Golden Eagle (top) passing the lookout along with a second-year Bald Eagle (bottom).Another “before-third-year” Golden Eagle. More are on the way!
Later this month, Bald Eagle numbers on the lower Susquehanna below Conowingo Dam (U.S. 1) near Rising Sun, Maryland, will begin to grow. Fisherman’s Park, located along the west shoreline below the dam, is an excellent place to observe and photograph scores of these regal birds. And few places provide a better opportunity to learn to differentiate Bald Eagle age classes. If you’re really lucky, a Golden Eagle or two may drop in as well. So plan to make the trip. The best time to visit is on a weekday. The parking lot can become overcrowded on weekends and will be closed under such circumstances. It’s best to avoid the long Thanksgiving weekend as well.
For many species of terrestrial vertebrates living in the lower Susquehanna valley, it’s time to take refuge in a safe place below ground to enter a winter-long slumber. The numerous frosty nights of the past two weeks have expedited the stragglers’ efforts to find a suitable place to pass our coldest months.
Aside from the Eastern Box Turtle (Terrapene carolina carolina), the Wood Turtle (Glyptemys insculpta) is our most terrestrial species of testudine, however it is seldom found far from wet bottomlands. Last week, we found this pair preparing to burrow into alluvial soils along the edge of a floodplain wetland where they will spend the winter. In recent years, Wood Turtle numbers have plummeted due to habitat fragmentation and loss, and due to collecting by short-sighted petkeepers and profiteers.A sluggish Wood Turtle catching a few last rays of sunshine before digging in for the winter. If you encounter these or any turtles now or at any time of year, it’s important that they not be disturbed. Look and leave them be.
And now, just in time for Halloween, a look at some hibernating species that some of our more squeamish readers consider to be “scary”.
In the mountainous forests of the Ridge and Valley Province, there lives a seldom seen little mouse which, unlike the more familiar species found in the fields, farms, and homes of our valleys and Piedmont, spends almost half the year in true hibernation.
The Woodland Jumping Mouse (Napaeozapus insignis) is a nocturnal species of rodent found primarily on rocky forest slopes, particularly those with growths of Eastern White Pine and Eastern Hemlock. Unlike the similar White-footed Mouse, a species that sometimes enters homes in the fall and remains active year-round, the Woodland Jumping Mouse builds a small subterranean nest among rocks and boulders where it will enter a long winter slumber, often not emerging until the milder days of April. During the long hibernation, these mice sometimes fatally diminish the energy stored in their body fat; up to 75% may perish before spring arrives (Merritt, 1987).
In spring and fall, Eastern (Black) Ratsnakes are frequently seen basking in the sun as they absorb heat and get their metabolism going. During the hottest days of summer, when ambient air temperature is sufficient for their needs, they become nocturnal, hunting mice and other creatures that are also active at night. During October, they make their way back to a winter den where they will remain until March or April.
A last-minute Eastern (Black) Ratsnake makes a slow late-October trek across a mountain road toward a winter den on the south slope of the ridge.This Eastern Ratsnake is on its way to a cold-season hideout where it may spend the darker months in the company of other communal hibernators including……Eastern Copperheads……and Timber Rattlesnakes.
That’s right, all three of these snakes are known to cohabitate, not just during hibernation, but at other times of the year as well. And you thought they were mean and nasty to anything and everything in their path, didn’t you?
Here in the northeastern United States, fear of indigenous wild snakes is a totally irrational anxiety. It’s a figment of our indoctrination. Their wicked reputation is almost exclusively the result of a never-ending stream of demonizing propaganda from the pulpit, press, parents, panicked, and picture shows. All they want from you and I is to be left alone. Want something to really be afraid of this Halloween? Try domestic dogs. That’s right—the “friendly” pooch. In the United States, they’ll land hundreds of people in the emergency room today. Don’t like that one. How ’bout cars and trucks. They’ll kill and maim people all day long. And don’t forget about sugar. Yes friends, that sweet treat is pure poison that kills all day long. Happy Halloween!
SOURCES
Merritt, Joseph F. 1987. Guide to the Mammals of Pennsylvania. University of Pittsburgh Press. Pittsburgh, PA. pp.230-233.
Shaffer, Larry L. 1991. Pennsylvania Amphibians and Reptiles. Pennsylvania Fish Commission. Harrisburg, PA.
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.
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.
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 (Rhus copallina), a small native tree. In case you’re wondering, it’s not poisonous.Black Chokeberry (Photinia melanocarpa), a native shrub also known as Aronia. It produces black-colored fruits in summer.Red-osier Dogwood (Cornus sericea), a shrub that prefers wet or damp soils. It yields white fruits.Maple-leafed Viburnum (Viburnum acerifolium), a native shrub of upland forest understories.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.
Another arrival from the northern forests, the diminutive Winter Wren is often difficult to observe. Look for it right now in wetlands, along wooded streams, and among fallen timber where it sometimes resembles a mouse scurrying about looking for food. In good habitat, some of these migrants will remain through the colder months and will on occasion burst into song. Hearing it is sure to brighten your day.
Going almost undetected, the Brown Creeper quietly probes the bark for spiders and tiny insects, as well as their eggs, larvae, and pupae. These unique little birds are rare breeders in the lower Susquehanna valley, finding larger tracts of forest to our north more to their liking. Now is perhaps the best time of year to find them, while their southbound migration reaches its peak. Small numbers of Brown Creepers stick around through winter, somehow finding enough to eat among the cracks and crevices of the tree trunks.
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.
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.
At last, the bird migration is picking up where it left off after the third week of September when rain, fog, and gloom arrived for a two week stay in the lower Susquehanna valley. Now that this persistent meteorological interluder has departed the stage, our stalled avians can resume the autumn spectacle.
There are still a few Barn Swallows around. By October, they’ve usually departed for more southern climes. Our more common late-season species are the Tree and Northern Rough-winged Swallows, both of which tend to be found close to water and are thus able to still grab flying insects on mornings when the air temperature over land is too cold for their favored prey. We found this Barn Swallow following the lead of its cool-weather counterparts, hawking up its breakfast over a warm sun-drenched pond.While the vast majority of the Neotropical flycatchers are now gone for the year, Eastern Phoebes are currently moving through in large numbers. Like the late-season swallows, these insectivores are a temperate species with an affinity for habitats near water.Though getting harder to find, there are still some Neotropical warblers moving through. This Black-throated Green Warbler was strongly outnumbered by the Ruby-crowned Kinglets in a mixed flock of woodland songbirds.A Northern Parula in the mixed flock of migrants.One of dozens of Ruby-crowned Kinglets encountered this morning.Despite the inclement weather, diurnal flights of southbound Blue Jays have continued throughout the past week.Migrating Blue Jays are best seen during the first few hours after sunrise.Red-bellied Woodpeckers, after extending their range north through the Susquehanna watershed and beyond during the past century, have now become a regular fall migrant as they withdraw from the northernmost periphery of their breeding grounds. This individual was photographed while taking a break from its diurnal flight and was one of more than three dozen seen at Second Mountain Hawk Watch on Thursday, October 3.After a significant delay, especially for the Neotropical Broad-winged Hawks, diurnal raptor flights have resumed. Now is the time to see the widest variety of species, including migrants like this Osprey, at any one of the regional hawk-counting stations.Numbers of migrating Sharp-shinned Hawks are now reaching their seasonal peak. Be certain to check out “Hawkwatchers Helper: Identifying Bald Eagles and Other Diurnal Raptors” by clicking the tab at the top of this page. There you’ll find a listing of regional lookouts and a photo guide to help you identify the species you see.
During this foggy, dreary week, if you happened to visit a parcel of land that included even a small patch of brushy growth here in the Lower Susquehanna River Watershed, you likely weren’t alone. Among the migrating songbirds grounded by the inclement weather were an abundance of these thicket-dwelling warblers—a species aptly named the Common Yellowthroat.
A Common Yellowthroat, on an extended layover due to flight cancellations imposed by this week’s moisture-laden east winds, peers from the dense cover of a tangle of shrubs and thorny vines.As soon as the inclement weather moves out, this adult male Common Yellowthroat and other avian migrants will resume their southbound journey. Until then, he has plenty of time to scrounge around in the low-growing vegetation for insects and other fare to replenish the energy stores needed for the trip.
Get ready. The sun will show its glow in just a couple of days and when it does, bottled-up birds are going to make a run for it. Do plan to get out and have a look later this week.
We have at last reached the autumnal equinox, a day when everything is even stephen, equal time both with and without sunlight. Southbound birds like this juvenile Scarlet Tanager can now freely be called “fall migrants”, even though the majority of tanagers and other Neotropical species departed for warmer climes earlier this month, technically during the summer season.
For the past several weeks, we’ve given you a look at the fallout of Neotropical songbirds on mornings following significant nocturnal flights of southbound migrants. Now let’s examine the diurnal (daytime) flights that have developed in recent days over parts of the lower Susquehanna basin and adjacent regions.
For those observing diurnal migrants, particularly at raptor-counting stations, the third week of September is prime time for large flights of tropics-bound Broad-winged Hawks. Winds from easterly directions during this year’s movements kept the greatest concentrations of these birds in the Ridge and Valley Province and upper areas of the Piedmont as they transited our region along a southwesterly heading. Counts topped 1,000 birds or more on at least one day at each of these lookouts during the past seven days. Meanwhile at hawk watches along the Piedmont/Atlantic Coastal Plain border, where flights topped 10,000 or more birds on the best days last fall, observers struggled to see 100 Broad-winged Hawks in a single day.
Dozens of migrating Broad-winged Hawks during a morning liftoff to the north of Blue Mountain.
Among the challenges counters faced while enumerating migratory Broad-winged Hawks this week was the often clear blue skies, a glaring sun, and the high altitude at which these raptors fly during the mid-day hours.
Large numbers of Broad-winged Hawks climbing on a thermal updraft to gain altitude can become increasingly difficult to spot in a clear blue sky.Higher and higher they go until they practically disappear from view.Cloud cover can help make locating really high-flying birds a bit easier, but they can sometimes climb into the lower portion of the cloud and vanish.
Another factor complicating the hawk counters’ tasks this week, particularly west of the Susquehanna River, was the widespread presence of another group of diurnal fliers.
Was it the migratory Blue Jays that are beginning to move through the area? No.Was it the increasing numbers of Sharp-shinned Hawks and other raptors? No.So what was it that complicated the hawkwatchers’ efforts to find high-flying Broad-winged Hawks during this week’s flights?Is it a bird? Is it a plane? No. And it’s nobody’s superhero either. It’s the non-native Spotted Lanternfly and it is now very numerous west of the Susquehanna and common enough to the east to make even experienced observers take a second look while scanning the skies for Broad-winged Hawks and other migrating raptors. Just how many do raptor counters have to contend with? Even where these invasive insects have become less populous in the lower Susquehanna valley, hundreds still fill the skies above forest clearings around hawk-counting stations including Waggoner’s Gap, Second Mountain, and Rocky Ridge County Park.Spotted Lanternfly populations explode with great vigor as they colonize areas with plenty of tender new growth on native, non-native, and cultivated shrubs, trees, and vines. Earlier this week, National Weather Service Doppler Radar in Pittsburgh, Pennsylvania, captured enormous mid-afternoon flights of Spotted Lanternflies in recently invaded areas of southwestern Pennsylvania and eastern Ohio. (NOAA/National Weather Service Doppler Radar image)A base velocity image consisting primarily of Spotted Lanternflies in southwestern Pennsylvania and eastern Ohio. (NOAA/National Weather Service Doppler Radar image)
As the Broad-winged Hawk migration draws to a close during the coming ten days, the occurrence of the one dozen other migratory diurnal raptors will be on the upswing. They generally fly at lower altitudes, often relying upon wind updrafts on the ridges for lift instead of high-rising thermal updrafts. They therefore present better observation opportunities for visitors at hawk watch lookouts and are less frequently confused with high-flying Spotted Lanternflies.
A Merlin seen earlier this week migrating through the Lower Susquehanna River Watershed. The numbers of migrating Merlins and other falcons will peak sometime in coming weeks.
Among the Green Frogs in the ponds at susquehannawildlife.net headquarters, a specific recessive allele is present among the population of these native amphibians. On occasions when male and female carriers of this particular recessive allele get together to produce offspring, about one quarter of the progeny will receive a copy of this mutated version of a gene from each parent. The rare recipient of this pair of recessive alleles that happens to survive the process of hatching from its egg and metamorphosing through the tadpole stage to adulthood will reveal the uncommon appearance of an amphibian with the condition resulting from this inheritance—axanthism.
Axanthic Green Frogs and other amphibians do not produce yellow pigment, therefore the normally yellow surfaces of their bodies appear white, the green surfaces blue. Axanthism is expressed only in individuals possessing a pair of specific recessive alleles for a gene that affects the cells that produce the yellow pigment. For the trait to be expressed, a frog must receive one copy of the recessive allele from each parent.The last axanthic Green Frog we saw in the headquarters ponds was this male (seen here with a typical male Green Frog) found back in July, 2008. Green Frogs that receive two copies of a dominant allele or a copy of a dominant and a recessive allele from their parents will not express the recessive trait for the axanthism gene. Making observation of cases of axanthism even rarer is the fact that blue coloration can make these frogs exceptionally susceptible to predation. Few live long enough to reproduce and thus increase the occurrence of the mutation in a population of frogs*. This cyanic individual was present during a time when “outdoor” Domestic Cats were killing frogs to take home to their misguided humans. After this brief sighting and single photograph, this blue Green Frog was never seen again.
*The incidence of axanthic frogs can increase when a blue parent, which has a pair of the recessive alleles and is therefore said to be homozygous recessive, mates with a typical-looking frog that carries both a dominant and a recessive allele for the axanthism gene and is therefore said to be heterozygous. Approximately 50% of the young from this pairing will express axanthism. By comparison, a pair of frogs that are both heterozygous will produce 25% axanthic young, and a pair of frogs that are both blue (homozygous) will yield 100% axanthic young. A pair of frogs that includes an individual that is herterozygous and a mate that is homozygous dominant for the gene will produce no axanthic frogs, but 50% of the young will be carriers of the recessive allele. A pair of homozygous dominant frogs produces no axanthic young and no carriers of the recessive allele.
It’s a sign that things are about to change. As the Neotropical warbler migration reaches its climax, other small songbirds like this Ruby-crowned Kinglet are beginning to make their southbound movements through the lower Susquehanna valley. For a kinglet, the autumn journey is greatly abbreviated compared to that of the Neotropical species. While the warblers and their traveling companions including vireos and flycatchers are primarily headed to the tropical climate zone for winter, kinglets spend the cold season in the temperate zone, an area encompassing most of the the continental United States and southern Canada. These tiny birds feed mostly on small invertebrates which, particularly during the winter months, they find in spaces among the bark of mature trees.
Yesterday morning’s fallout of hundreds of nocturnally migrating birds was followed overnight by the influx of one hundred or more new arrivals atop Second Mountain in Lebanon County, Pennsylvania. Visitors to the forest clearing used as a hawk watch lookout were treated to the antics of these colorful Neotropical species and more…
These night-flying warblers, vireos, and flycatchers did again provide a thrilling show during the hours after sunrise, but today’s rarity passed through among the hundreds of migrating diurnal raptors—the tropics-bound Broad-winged Hawks—that made their way down the ridges of the lower Susquehanna valley this afternoon.
A “kettle” of Broad-winged Hawks climbing on a thermal updraft above Second Mountain Hawk Watch.After gaining altitude, Broad-winged Hawks glide away toward the southwest in search of the next thermal updraft upon which they will rise to continue their journey to Texas, Mexico, and beyond. Over three hundred of these raptors were counted as they passed the Second Mountain lookout today.Another “kettling” flock of migrating Broad-winged Hawks above Second Mountain.A closer look reveals something unusual. While the Broad-winged Hawk at the bottom center of the image displays the typical light-morph plumage, the bird in the upper left appears to be a dark-morph Broad-winged Hawk, a rarity in the eastern United States.A zoomed-in view of the probable dark-morph Broad-winged Hawk seen over Second Mountain this afternoon. Populations of these variants nest in areas of central and western Canada.
The peak of the autumn Broad-winged Hawk migration will likely occur during the coming two weeks with many counting stations tallying more than one thousand birds on the best of days. Visit one of these prominent lookout points so that you too can witness this amazing spectacle. Click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page to find a hawk watch near you!
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.
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).A Blackpoll Warbler.The Bay-breasted Warbler, another common species found among the fallout flock.The Tennessee Warbler was today’s most abundant migrant with at least 200 birds seen moving among the other species.A newly arrived Tennessee Warbler at sunrise.A Tennessee Warbler snatches breakfast.The Magnolia Warbler was another common find among today’s migrants.A Magnolia Warbler.A Nashville Warbler among tangles of Mile-a-minute Weed.A Nashville Warbler.Black-throated Blue Warbler.An adult male Black-throated Blue Warbler.An acrobatic Northern Parula.Blackburnian Warblers continue their southerly trek.An American Redstart.A Chestnut-sided Warbler feeding on Mile-a-minute Weed berries.A Cape May Warbler.A handsome adult male Cape May Warbler.A Swainson’s Thrush.Scarlet Tanagers continue to work their way south through the Lower Susquehanna River Watershed.A composite image of an uncommon find, a large-headed Olive-sided Flycatcher seen perched atop a dead tree snag.A brief encounter with a Philadelphia Vireo, another uncommon species.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.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)
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…
A Black-throated Green Warbler.The Black-throated Green Warbler was perhaps the most frequently identified treetop warbler during the most recent four mornings.A Black-throated Green Warbler with a unique variation in the crown plumage.The Blackburnian Warbler was another plentiful species.Cape May Warblers have an affinity for conifers like this Eastern White Pine.But when traveling in mixed flocks with other migrants, Cape May Warblers can also be found feeding in the crown foliage of deciduous trees.This adult Tennessee Warbler appears to be adorned in a very worn set of plumage……and its traveling companion looks like it’s overdue for a new set of feathers as well.Like the Tennessee Warbler, the Nashville Warbler was common among mixed flocks.A Nashville Warbler atop a Black Cherry.This Chestnut-sided Warbler was one of several found among the more common species of migrants.A Chestnut-sided Warbler.We were lucky enough to spot this male Chestnut-sided Warbler sporting his namesake flank feathers.A Black-and-white Warbler uses its nuthatch-like feeding behavior to search the tree bark for edible invertebrates.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.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.Here we found a perky little House Wren.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.An Eastern Wood-Pewee fiercely defending its hunting perch.An Eastern Wood-Pewee.The numbers of migrating Least Flycatchers and other members of the genus Empidonax may be reaching their seasonal peak this week.Scarlet Tanagers are currently a common find following nocturnal flights.A Scarlet Tanager peers down from the top of a Red Maple.Did you hear a loud squeak in the treetops? It could be a southbound Rose-breasted Grosbeak stopping by for the day.A Rose-breasted Grosbeak in a dead tree snag.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.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……several hungry Yellow-throated Vireos arriving after nocturnal flights,……and a Philadelphia Vireo (Vireo philadelphicus) at the hawkwatch at Rocky Ridge County Park in York County.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 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.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.A juvenile Red-headed Woodpecker during a brief pit stop.The flights of roving bands of masked Cedar Waxwings continue. Their numbers appear to be an improvement over those of 2023.At regional hawk-counting stations, observers are seeing more Broad-winged Hawks and other species beginning to move through.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.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.
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)
Back on March 24th, we took a detailed look at the process involved in administering prescribed fire as a tool for managing grassland and early successional habitat. Today we’re going turn back the hands of time to give you a glimpse of how the treated site fared during the five months since the controlled burn. Let’s go back to Middle Creek Wildlife Management Area for a photo tour to see how things have come along…
Pennsylvania Game Commission crews administering prescribed fire on a grassland demonstration site back on March 16.By late May, native herbaceous perennial wildflowers including Joe-pye Weed had re-greened the site. One of the goals of the burn was to kill fire-sensitive woody plants, thus preventing the process of succession from reforesting the site.The scorched, lifeless remains of small trees and shrubs indicate that that goal was met.Because prescribed fire is administered in a mosaic pattern that permits some early successional growth to remain until the next burn, birds including this thicket-nesting Yellow-breasted Chat are able to take advantage of the mixed habitat during their breeding season in May and June.By August, the site is a haven for native plants and animals.The burn has promoted the growth and late-summer bloom of fire-tolerant native wildflowers and warm-season grasses……including Indiangrass,……Big Bluestem……Thin-leaved Coneflower (Rudbeckia triloba), a plant also known as Brown-eyed Susan,……and Joe-pye Weed, a plant butterflies find irresistible.Eastern Tiger Swallowtail collecting nectar from Joe-pye Weed.A black-morph Eastern Tiger Swallowtail collecting nectar from Spotted Knapweed (Centaurea steobe micranthos), a non-native invasive plant found growing in an area of the burn site missed by this year’s fire. While many non-native plants are unable to survive the flames and heat produced by prescribed fire, it isn’t an absolute cure-all. It doesn’t eliminate all invasive plants, it just keeps them from dominating a landscape by out-competing native species. Left unmanaged, Spotted Knapweed is a tough perennial invasive that can easily become one the species able to overtake a vulnerable grassland. It can be a stubborn survivor of some prescribed burns. On the plus side, butterflies really like it.By August, native grassland plants in the prescribed fire area were already providing an abundance of seeds for birds including this American Goldfinch.For larger birds like turkeys and pheasants, an abundance of Carolina Grasshoppers are providing a protein-dense food source in managed grasslands.And tiny flying insects, a nuisance to us as we take a stroll alongside the grasslands, are a meal taken on the wing by dragonflies including this Black Saddlebags.
Elsewhere around the refuge at Middle Creek, prescribed fire and other management techniques are providing high-quality grassland habitat for numerous species of nesting birds…
Bobolinks nested both in areas subjected to controlled burns……and in hay fields where mowing was delayed until the nesting season, including the fledging process, was completed earlier this month.As advertised, Grasshopper Sparrows nested in these fields as well.
We hope you enjoyed this short photo tour of grassland management practices. Now, we’d like to leave you with one last set of pictures—a set you may find as interesting as we found them. Each is of a different Eastern Cottontail, a species we found to be particularly common on prescribed fire sites when we took these images in late May. The first two are of the individuals we happened to be able to photograph in areas subjected to fire two months earlier in March. The latter two are of cottontails we happened to photograph elsewhere on the refuge in areas not in proximity to ground treated with a prescribed burn or exposed to accidental fire in recent years.
Eastern Cottontail at a site subjected to prescribed fire earlier in the spring.Eastern Cottontail at a site subjected to prescribed fire earlier in the spring.
These first two rabbits are living the good life in a warm-season grass wonderland.
Eastern Cottontail at a site not subjected to any recent fire activity.Eastern Cottontail at a site not subjected to any recent fire activity.
Oh Deer! Oh Deer! These last two rabbits have no clock to track the time; they have only ticks. Better not go for a stroll with them Alice—that’s no wonderland! I know, I know, it’s time to go. See ya later.
The Aphrodite Fritillary (Speyeria aphrodite), also known simply as the Aphrodite, is a brush-footed butterfly of deciduous, coniferous, and mixed forests. We found this female in a grassland margin between woodlots where prescribed fire was administered during the autumn of 2022 to reduce accumulations of natural fuels and an overabundance of invasive vegetation. A goal of the burn was to promote the growth of native species including the violets (Viola species) favored as larval host plants by this and other fritillaries.
A female Aphrodite Fritillary collecting nectar from a thistle flower.
By the time these adult butterflies make their reproductive flights in late summer, the violets that serve as larval host plants have gone dormant. To find patches of ground where the violets will come to life in spring, the female Aphrodite Fritillary has an ability to sense the presence of dormant roots, probably by smell. Upon finding an area where suitable violets will begin greening up next year, she’ll deposit her eggs. The eggs overwinter, then hatch to feed on the tender new violet leaves of spring.
A female Aphrodite Fritillary. A prescribed burn, when administered during spring to manage fritillary habitat, is applied only to a portion of the land parcel each year to avoid decimating an entire population of the larvae during the first instar of their life cycle, a time when they are vulnerable to fire.Our female Aphrodite Fritillary busily gathers nutritious nectar to provide sufficient energy for the critical process of mating and egg production. What’s the thistle that this goddess of love and procreation is pollinating?…It’s a non-native invasive, the Bull Thistle (Cirsium vulgare), a species that readily colonizes new areas by producing an abundance of airborne seeds. Continued management of this site with periodic applications of prescribed fire will prevent Bull Thistle and other invasives from overtaking the habitat during coming years.
Here’s a native plant you don’t see very often, but Ruby-throated Hummingbirds have a knack for finding and adoring it within the limited habitat where it still exists.
Allegheny Vine (Adlumia fungosa), also known as Climbing Fumitory or Mountain Fringe, is a seldom-found biennial herbaceous plant in the poppy family (Papaveraceae). Both its divided leaves and drooping clusters of flowers might remind the observer of a more familiar member of the poppy family, the spring-blooming Dutchman’s Breeches. But unlike the low-growing Dutchman’s Breeches, Allegheny Vine ascends nearby shrubs and small trees with trailing stems that add a garland-like pizzazz to the summertime foliage.Seen here creeping atop a small Sassafras (Sassafras albidum) tree, Allegheny Vine seldom escapes notice by the Ruby-throated Hummingbird, a primary pollinator of the plant.Allegheny Vine grows on moist, rocky slopes and blooms in late summer, just in time to refuel migrating Ruby-throated Hummingbirds.
Not likely to thrive in deep forest cover, Allegheny Vine is a denizen of edge habitat. The species is dependent on some type of disturbance to maintain suitable growing conditions. The plants seen here were found flowering in an area that had experienced a fire prior to last year’s growing season. It is therefore quite possible that the fire completed the stratification process and triggered long-dormant seeds to germinate last spring or summer to develop a basal plant which matured and flowered during this second summer of the biennial’s growth. On a forested slope opposite this site, a first-ever prescribed burn was conducted in March of this year to eliminate accumulated fuel and replicate a natural fire cycle. With a little luck, this forest management approach may prompt additional long-dormant Allegheny Vine seeds to germinate and form basal plants this year for maturation in 2025. Without man-made disturbances, Allegheny Vine may remain viable as a species by enduring seed dormancy periods of 40-100 years or more between fires, lightning strikes, wind storms, ice accumulations, and other events which clear the canopy and encourage growth.
Many years in the making, Allegheny Vine nectar must be delectable because the hummers can’t leave it alone. And another plus, with a little help from prescribed fire, this native creeping plant seems to be holding its own while in direct competition with invasive Mile-a-minute Weed (leaves in lower right).
The tiny flycatchers of the genus Empidonax are notoriously difficult to identify by visual clues alone. Determining the species by sight requires a good look under ideal conditions. Even then, these birds are a tricky lot. Don’t believe it? Take a gander at these photos of an Empidonax flycatcher found atop Second Mountain in Lebanon County at sunrise this morning…
One of the telltale signs of an Empidonax flycatcher from outside the group of eastern species is the presence of an expanded rear edge of a well-defined eye ring.Only the Pacific-slope and Cordilleran Flycatchers, groups currently lumped together by taxonomists as the Western Flycatcher, exhibit the teardrop-shaped eye ring. In the lower Susquehanna region, Western Flycatchers have been recorded as vagrants during autumn and in early winter on several occasions, most recently along the river in Conoy Township, Lancaster County, in December of 2023. (See post from December 20, 2023)For now, that 2023 record will remain the most recent. With a turn of its head providing a better angle in direct sunlight, the apparent expansion of the rear portion of the eye ring turns out to be little more than a pale post-ocular feather on this bird. The broad (but uniform) eye ring, rounded head, small bill, short tail, and the unbroken coloration of the underside areas all conspire to indicate that this is probably a Yellow-bellied Flycatcher (Empidonax flaviventris). Disappointing? Hardly. Yellow-bellied Flycatchers are strictly migrants in the Lower Susquehanna River Watershed. They are rarely seen as they pass through traveling to and from their breeding grounds in the moist coniferous forests, bogs, and swamps of the northernmost United States and southern Canada. A Neotropical species, the Yellow-bellied Flycatcher winters in southern Mexico and Central America.
It’s hard to believe, but for almost two months now, sandpipers, plovers, and terns have been filtering south through the Lower Susquehanna River Watershed on their way to the Atlantic coastline as they complete the first leg of their long autumn migration—a journey that will take some species all the way to the far reaches of the South American continent for winter.
Migrating Caspian Terns and an Osprey take a break on a lower Susquehanna valley gravel bar.
As August draws to a close, these early birds are being joined by widespread nocturnal flights of Neotropical migrants—those species, primarily songbirds, on their way to wintering grounds which lie exclusively south of the continental United States.
To catch a glimpse of these night-flying avians, your best bet may be to position yourself on the crest of a ridge or along a linear break in the forest such as a utility right-of-way where waves of warblers, vireos, flycatchers, and other Neotropical passerines sometimes feed on invertebrates after making landfall at daybreak. Pick a place where the trees are bathed in the warm light of the rising sun and be there by 7 A.M. E.D.T. The activity can be tremendous, but it usually ends between 8 and 9.
One of more than half a dozen Red-eyed Vireos seen during a daybreak fallout at Second Mountain Hawkwatch in Lebanon County earlier this week.During sunrise, a just-arrived Blackburnian Warbler checks the foliage of a ridgetop Red Maple for insects.A Least Flycatcher quietly searches the shrubby growth along the forest edge for a morning meal.A Black-and-white Warbler in the first hour of sunlight after a big nocturnal flight.A Scarlet Tanager having a look around. This individual and other migrating birds may be here for a few days before moving on.A Black-throated Green Warbler in a treetop glowing with the light of sunrise.A hungry Chestnut-sided Warbler inspects limbs, leaves, and twigs looking for nourishment after an all-night flight.
Diurnal migrants, birds that make their movements during the daylight hours, are ramping up their flights now as well. Broad-winged Hawks, Bald Eagles, and falcons are currently being tallied at hawk-counting stations throughout the northeast. Many of those lookouts are seeing Ruby-throated Hummingbirds, swallows, and other daytime migrants too.
While many diurnal migrants gather in flocks as a method of defense against predators, Broad-winged Hawks congregate as a reconnaissance measure. Not waiting around for strong autumn winds to be deflected upwards by the region’s numerous ridges, these Neotropical birds migrate early enough in the season to rely upon thermal updrafts from sun-heated surfaces to provide lift, gain altitude, and save energy during their long trip. By traveling in groups, there are collectively able to better locate and utilize rising air columns as they progress southwesterly along their route. Broad-winged Hawks travel to Central and South America for winter. Their numbers in the Lower Susquehanna River Watershed will peak during the third week of September.Many American Kestrels transit our area in August and early September, a time coinciding with flights of migratory dragonflies, insects upon which they and another falcon, the Merlin, frequently prey.Chimney Swifts are fast-flying diurnal migrants. They are beginning to congregate into larger groups in preparation for their departure. Some are already on the move.Cedar Waxwings are currently being seen in roving flocks throughout the region. Their migration is less of a point-to-point flight and more of a continuous wandering in search of berries and other wild foods.Not everyone is yet ready to go. American Goldfinches are still in the midst of their nesting cycle and won’t begin leaving until the young are on their own and colorful adult males like this one are beginning to molt into their drab winter plumage.
Autumn migration flights are an ever-changing process, with different species peaking at different times throughout the season. In these months just after the nesting season, each of these species is more numerous than at any other time of the year. And of course, the more often we as observers get out and have a look, the more of them we’ll see.
Be certain to click the “Birds” tab at the top of this page for a photo guide to the species you’re likely to see passing through the lower Susquehanna valley this fall. Nearly four months of autumn hawk migration flights lie ahead, so don’t forget to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab to find a hawk-counting station near you, then stop by for a visit or two. See you there!
A large nightfall liftoff of nocturnal migrating birds is shown here on this evening’s State College, Pennsylvania, Doppler Radar base velocity loop. Returns indicating birds moving toward the radar site (the white dot in the center of the color mass) are shown in green, and those indicating birds moving away are indicated in red. This is a big flight headed generally in a south-southwest direction. (NOAA/National Weather Service Doppler Radar image)
