Migration Update

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

See you next time!

October Transition

Thoughts of October in the Lower Susquehanna River Watershed bring to mind scenes of brilliant fall foliage adorning wooded hillsides and stream courses, frosty mornings bringing an end to the growing season, and geese and other birds flying south for the winter.

The autumn migration of birds spans a period equaling nearly half the calendar year.  Shorebirds and Neotropical perching birds begin moving through as early as late July, just as daylight hours begin decreasing during the weeks following their peak at summer solstice in late June.  During the darkest days of the year, those surrounding winter solstice in late December, the last of the southbound migrants, including some hawks, eagles, waterfowl, and gulls, may still be on the move.

The Rough-legged Hawk (Buteo lagopus), a rodent-eating raptor of tundra, grassland, and marsh, is rare as a migrant and winter resident in the lower Susquehanna valley.  It may arrive as late as January, if at all.

During October, there is a distinct change in the list of species an observer might find migrating through the lower Susquehanna valley.  Reduced hours of daylight and plunges in temperatures—particularly frost and freeze events—impact the food sources available to birds.  It is during October that we say goodbye to the Neotropical migrants and hello to those more hardy species that spend their winters in temperate climates like ours.

During several of the first days of October, two hundred Chimney Swifts remained in this roost until temperatures warmed from the low forties at daybreak to the upper fifties at mid-morning; then, at last, the flock ventured out in search of flying insects.  When a population of birds loses its food supply or is unable to access it, that population must relocate or perish.  Like other insectivorous birds, these swifts must move to warmer climes to be assured a sustained supply of the flying bugs they need to survive.  Due to their specialized food source, they can be considered “specialist” feeders in comparison to species with more varied diets, the “generalists”.  After returning to this chimney every evening for nearly two months, the swifts departed this roost on October 5 and did not return.
A Northern Parula lingers as an October migrant along the Susquehanna.  This and other specialist feeders that survive almost entirely on insects found in the forest canopy are largely south of the Susquehanna watershed by the second week of October.
The Blackpoll Warbler is among the last of the insectivorous Neotropical warblers to pass through the riparian forests of the lower Susquehanna valley each fall.  Through at least mid-October, it is regularly seen searching for crawling insects and larvae among the foliage and bark of Northern Hackberry (Celtis occidentalis) trees near Conewago Falls.  Most other warblers, particularly those that feed largely upon flying insects, are, by then, already gone.
The Blue-headed Vireo, another insectivore, is the last of the vireo species to pass through the valley.  They linger only as long as there are leaves on the trees in which they feed.
Brown Creepers begin arriving in early October.  They are specialist feeders, well-adapted to finding insect larvae and other invertebrates among the ridges and peeling bark of trees like this hackberry, even through the winter months.
Ruby-crowned Kinglets can be abundant migrants in October.  They will often behave like cute little flycatchers, but quickly transition to picking insects and other invertebrates from foliage and bark as the weather turns frosty.  Some may spend the winter here, particularly in the vicinity of stands of pines, which provide cover and some thermal protection during storms and bitter cold.
Beginning in early October, Golden-crowned Kinglets can be seen searching the forest wood for tiny invertebrates.  They are the most commonly encountered kinglet in winter.
The Yellow-bellied Sapsucker, a woodpecker, is an October migrant that specializes in attracting small insects to tiny seeps of sap it creates by punching horizontal rows of shallow holes through the tree bark.  Some remain for winter.
The Yellow-rumped Warbler arrives in force during October.  It is the most likely of the warblers to be found here in winter.  Yellow-rumped Warblers are generalists, feeding upon insects during the warmer months, but able to survive on berries and other foods in late fall and winter.  Wild foods like these Poison Ivy berries are crucial for the survival of this and many other generalists.
American Robins are most familiar as hunters of earthworms on the suburban lawn, but they are generalist feeders that rely upon fruits like these Eastern Red Cedar (Juniperus virginiana) berries during their southbound migration in late October and early November each year.  Robins remain for the winter in areas of the lower Susquehanna valley with ample berries for food and groves of mature pines for roosting.
Like other brown woodland thrushes, the Hermit Thrush (Catharus guttatus) is commonly seen scratching through organic matter on the moist forest floor in search of invertebrates.  Unlike the other species, it is a cold-hardy generalist feeder, often seen eating berries during the southbound October migration.  Small numbers of Hermit Thrushes spend the winter in the lower Susquehanna valley, particularly in habitats with a mix of wild foods.
Due to their feeding behavior, Cedar Waxwings can easily be mistaken for flycatchers during the nesting season, but by October they’ve transitioned to voracious consumers of small wild fruits.  During the remainder of the year, flocks of waxwings wander widely in search of foods like this Fox Grape (Vitis labrusca).  An abundance of cedar, holly, Poison Ivy, hackberry, bittersweet , hawthorn, wild grape, and other berries is essential to their survival during the colder months.
Red-breasted Nuthatches have moved south in large numbers during the fall of 2020.  They were particularly common in the lower Susquehanna region during  mid-October.  Red-breasted Nuthatches can feed on invertebrates during warm weather, but get forced south from Canada in droves when the cone crops on coniferous trees fail to provide an adequate supply of seeds for the colder fall and winter seasons.  In the absence of wild foods, these generalists will visit feeding stations stocked with suet and other provisions.
Purple Finches (Haemorhous purpureus) were unusually common as October migrants in 2020.  They are often considered seed eaters during cold weather, but will readily consume small fruits like these berries on an invasive Mile-a-minute Weed (Persicaria perfoliata) vine.  Purple Finches are quite fond of sunflower seeds at feeding stations, but often shy away if aggressive House Sparrows or House Finches are present.

The need for food and cover is critical for the survival of wildlife during the colder months.  If you are a property steward, think about providing places for wildlife in the landscape.  Mow less.  Plant trees, particularly evergreens.  Thickets are good—plant or protect fruit-bearing vines and shrubs, and allow herbaceous native plants to flower and produce seed.  And if you’re putting out provisions for songbirds, keep the feeders clean.  Remember, even small yards and gardens can provide a life-saving oasis for migrating and wintering birds.  With a larger parcel of land, you can do even more.

GOT BERRIES?  Common Winterbery (Ilex verticillata) is a native deciduous holly that looks its best in the winter, especially with snow on the ground.  It’s slow-growing, and never needs pruning.  Birds including bluebirds love the berries and you can plant it in wet ground, even along a stream, in a stormwater basin, or in a rain garden where your downspouts discharge.  Because it’s a holly, you’ll need to plant a male and a female to get the berries.  Full sun produces the best crop.  Fall is a great time to plant, and many garden centers that sell holiday greenery still have winterberry shrubs for sale in November and December.  Put a clump of these beauties in your landscape.  Gorgeous!

A Visit to Waggoner’s Gap

Nothing beats spending a day at a hawk watch lookout—except of course spending a day at a hawk watch lookout when the birds are parading through nonstop for hours on end.

Check out Waggoner’s Gap, a hawk count site located on the border of Cumberland and Perry Counties atop Blue Mountain just north of Carlisle, Pennsylvania.  It is by far the Lower Susquehanna River Watershed’s best location for observing large numbers of migrating raptors during the October and November flights.

Waggoner’s Gap is located where Route 74 crosses Blue Mountain north of Carlisle.
The entrance to a parking area for hawk watch visitors is designated by this sign located along Route 74 several hundred yards north of the summit of Blue Mountain.
Since acquiring the site in 2000, Audubon Pennsylvania has added improvements to expand the function of Waggoner’s Gap Hawk Watch to include education for both formal students and the public at large.
The site is named in honor of the late conservationist Clifford L. Jones, a business leader, a former Chairman of the Pennsylvania Public Utilities Commission, a cabinet secretary for six Pennsylvania governors (both major parties), a director on the boards of numerous conservation organizations, and an active birder.
Orange falcon silhouettes function as blazes for the trails that lead from the parking area to the lookout.  The trail and the lookout consist entirely of boulders.  Some of these move when stepped upon.  Others may be slick.  Use caution at all times.
The lookout at Waggoner’s Gap is staffed by official counters from August through December each year.  They are tasked with enumerating every migratory raptor’s passage during that period.
Sure-footed observers climb into a comfortable position among the Tuscarora quartzite boulders and begin watching the flight.
The view from the lookout is spectacular.  To the east, downtown Harrisburg can be seen in the distance.
During a recent afternoon with breezes from the “southwesterlies”, a steady stream of  migrating Sharp-shinned Hawks, including this juvenile, passed by the lookout.
Sharp-shinned Hawks were ready subjects for photography as they sailed on updrafts along the south side of the ridge.
An adult Sharp-shinned Hawk.
A second-year Sharp-shinned Hawk.
A Sharp-shinned Hawk below eye level.  Over 400 Sharp-shinned Hawks migrated past Waggoner’s Gap Hawk Watch on this particular early October day.
The local Turkey Vultures at Waggoner’s Gap seem ubiquitous at times.  They’re on the radio towers, they’re flying overhead, and a few are cruising the slopes below the crest.  But on the day of our recent visit, their numbers were eclipsed by the more than 300 “T.V.s” that migrated down the ridge.
Black Vultures, both migrants and local birds, are seen from the lookout.
Northern Harriers are a hawk watch favorite.  Their long uptilted wings, long tail, and white rump make them easy to identify, even for beginners.  Their plummeting numbers make them a treasured sighting for everyone.
A Red-tailed Hawk on a close approach.
A distant Red-shouldered Hawk.  Numbers of these migrants peak later in the season.
A Peregrine Falcon darts past the lookout.  Note the white forehead, throat, and breast.  This bird is probably a “Tundra Peregrine” (Falco peregrinus tundrius).  In the lower Susquehanna valley, this subspecies is strictly migratory, a transient in spring and fall.  “Tundra Peregrines” breed in the arctic and winter as far south as South America.
An immature Bald Eagle.  Waggoner’s Gap is a superb place for sighting eagles, especially on a breezy day.
Hundreds of Blue Jays filtered through as their southbound exodus continues.  Other songbirds of interest included Blue-headed Vireos (Vireo solitarius), Winter Wrens, Red-breasted Nuthatches, Pine Siskins, and both Ruby-crowned and Golden-crowned Kinglets.

Waggoner’s Gap is a hardy birder’s paradise.  During the latter portion of the season, excellent flights often occur on days that follow the passage of a cold front and have strong northwest winds.  But be prepared, it can be brutal on those rocks during a gusty late-October or early-November day after the leaves fall—so dress appropriately.

To see the daily totals for the raptor count at Waggoner’s Gap Hawk Watch and other hawk watches in North America, and to learn more about each site, be sure to visit hawkcount.org