In early April of each year, we like to take a dreary-day stroll along the Susquehanna in Harrisburg to see if any waterfowl or seabirds have dropped in for a layover before continuing their journey from wintering waters along the Atlantic seaboard to breeding areas well to our north and northwest. As showers started to subside this Saturday morning past, here are some of the travelers we had the chance to see…
Hundreds of scaup were feeding at mid-river. To remain in suitable foraging habitat, the group is seen here flying upstream to the area of the Governor’s Mansion where they would commence yet another drift downstream to Independence Island before again repositioning to a favorable spot.By far, the majority of the ducks in this flock were Lesser Scaup showing white inner margins of the secondary flight feathers and more grayish margins in the primaries. Several Greater Scaup, including the one denoted by the hairline in this image, could be detected by the presence of bright white margins not only in the secondary flight feathers, but extending through the primaries as well.A pair of Lesser Scaup feeding along the river shoreline at the Governor’s Mansion. Both scaup species spend the colder months in bays and coastal estuaries, but the Lesser Scaup is the most likely to be found venturing inland to fresh water in the southern United States during winter. The Lesser Scaup nests in the northwestern United States and in the southern half of Canada. The Greater Scaup is the more northerly nesting species, spending its summers at the northern edges of the border provinces and beyond.Common Loons spend the winter in Atlantic surf. April is the best time to see them on the lower Susquehanna River as they drop in to rest and reenergize during a break in their annual northbound trip to nesting sites on the lakes and ponds left behind by the retreat of Pleistocene glaciers.We saw dozens of Buffleheads during our morning hike, often segregated into paired couples like this one. Being cavity nesters, these migrating ducks are headed no further north than southern Canada, to lakes and ponds within forests, for the summer.Harlequin Ducks (Histrionicus histrionicus) spend the summer nesting on turbulent high-gradient streams in Canada and Greenland. They mostly winter along rocky coastlines as far south as New England, but have adapted to feeding along man-made rock jetties in coastal New York and New Jersey. This winter, they were seen along jetties and sea walls at least as far south as Cape Charles, Virginia, and the mouth of Chesapeake Bay. During the past month, at least two Harlequin Ducks, including this male seen in flight on Saturday, have appeared on the river in the Harrisburg area, possibly as strays from this year’s wintering population at the mouth of the bay. These ducks are very rare habitat specialists, possibly (according to Behrens and Cox, 2013) numbering less than 1,500 birds along the entire east coast.In spring, the Horned Grebe transitions from a drab gray-brown winter (basic) plumage into rather surprisingly colorful breeding (alternate) plumage.An adult Horned Grebe in breeding (alternate) plumage. Horned Grebes spend the winter on large rivers, bays, and ocean waters from Nova Scotia to Texas. They are presently on their way to breeding areas on ponds and lakes in Alaska and Canada west of Ontario.
If you want a chance to see these seldom-observed visitors to the lower Susquehanna at Pennsylvania’s capital city, try a morning walk along mid-town’s Riverfront Park from Maclay Street to Forster Street. Also, try a stroll on City Island, particularly to the beach at the north end where you have a view of the mid-river areas upstream. To have better afternoon light, try the river’s west shore along Front Street in Wormleysburg from the Market Street Bridge upstream to Conodoguinet Creek. Once there, be certain to check the river from the Pennsylvania Fish and Boat Commission’s West Fairview Access Area at the mouth of the creek. And don’t be afraid to visit on a gloomy day; you never know what you might find!
Don’t forget to check the trees along the river shoreline where early stonefly hatches can often attract hungry insectivores. We found this and six other Eastern Phoebes crowded into the trees at water’s edge just upriver from the Governor’s Mansion during Saturday’s migrant fallout.
SOURCES
Behrens, Ken, and Cameron Cox. 2013. Seawatching: Eastern Waterbirds in Flight. Houghton Mifflin Harcourt Publishing Company. New York, NY.
Colorful songbirds like this Palm Warbler are beginning to migrate through the lower Susquehanna valley on their way north. Even when the weather is damp and gloomy, be certain to spend some time outdoors if you’d like the chance to see them. Palm Warblers are most frequently found in damp thickets and streamside, but they’ll sometimes show up in densely vegetated parks and gardens during a springtime fallout.
During Saturday’s Prescribed Fire Demonstration at the Pennsylvania Game Commission’s Middle Creek Wildlife Management Area, we noticed just how fast some species of wildlife return to areas subjected to burns administered to maintain grassland habitat and reduce the risk of high-intensity blazes.
Pennsylvania Game Commission crews ignite a back fire to contain a prescribed burn along its downwind/upslope perimeter during a demonstration at Middle Creek Wildlife Management Area on Saturday.Visitors observe a fire planned to maintain this section of the refuge as warm-season grassland. A species with roots several feet deep, the light-colored vegetation is Indiangrass, a plant adapted to thrive following periodic episodes of wildfire. Prescribed fire can be used to replace naturally occurring infernos with much safer controlled burns that eliminate successional and invasive plants to promote the establishment of Indiangrass and other native warm-season species including Big Bluestem, Little Bluestem, Switchgrass, and a variety of wildflowers as well.Even as the fire reached its brief peak of intensity, we noticed birds already attracted to the site…Dozens of recently arrived Tree Swallows swept in to patrol for flying insects as the burn was in progress.One even stopped by to have a look inside the kestrel nest box as fire approached the dry stand of goldenrod on the slope behind.Red-tailed Hawks and other raptors, including nocturnal owls, are frequently the first visitors attracted to the scene of a prescribed burn or wildfire. In grassland and successional habitats, they come looking for any vulnerable voles or mice that may be moving about looking for cover.
These three Eastern Meadowlarks spent the morning in the grassland areas adjacent to the prescribed fire site, mostly where a burn had been conducted one week prior. During the demonstration, one even perched and sang from the oak trees in the museum/visitor’s center parking lot.
Following the Prescribed Fire Demonstration, we decided to pay a visit to some of the parcels where burns had been administered one week earlier on the north side of Middle Creek’s main impoundment. We found a surprising amount of activity.
Apparently feeding upon slightly heat-treated seeds, sparrows were found by the dozens. White-crowned (left), White-throated (right), Song, and Savannah Sparrows were identified.This Downy Woodpecker was finding something to its liking among the scorched leaves, stems, and twigs.American Robins seem to find areas with lightly burnt vegetation and ash-dusted soil advantageous for finding invertebrates following a fire.We found this flock of Red-winged Blackbirds, Browned-headed Cowbirds, and a few European Starlings feeding throughout a grassland field cleared of early-successional growth by a prescribed fire administered one week ago.They seemed to favor gleaning seeds from among the lightly burned areas of the plot.Nearby, in an island of unburned grass in the same field, we found yet another Eastern Meadowlark, our fourth of the day. High-intensity agriculture, particularly early hay mowing and pesticide treatments, have mostly eliminated this and other grassland species from modern farms. Management practices like prescribed fire and delayed mowing (no spinning blades until at least early August) can maintain ideal grassland habitat for stunningly colorful blackbirds including nesting Eastern Meadowlarks, Bobolinks, and many other species as well.A male American Kestrel at a nest box located among Middle Creek’s warm-season and cool-season grassland habitats, the former maintained by prescribed fire, the latter by delayed mowing.
Find a stand of Common Cattails in a marsh, a stormwater basin, or along a pond edge right now and you’re almost certain to find a male Red-winged Blackbird ……singing and displaying to defend a territory and attract a partner. Upon their arrival and selection of a mate, the brown-streaked females will weave well-hidden nests among the stems and leaves of these essential water-purifying wetland plants.
It appears that spring has at last arrived. It’s time to have a look around!
Diurnal flights of northbound blackbirds including Common Grackles have been overspreading the Lower Susquehanna River Watershed since late February.And thawed soils are providing opportunities for nocturnal migrants like American Robins to search for earthworms and other invertebrates during their daytime layovers.Now that there is open water between here and the Great Lakes, flocks of waterfowl like these migratory Canada Geese are flying day and night on an excursion that will ultimately take them to their nesting grounds in the wilderness areas of Canada and Alaska.
Of the bird species that pass southbound through the lower Susquehanna valley during autumn, we can generally observe many of the surviving individuals as they return north during the spring. But there are numerous exceptions. One of them is Golden Eagles.
While the strong northwest winds of late autumn create ideal lift for migrating Golden Eagles along our linear ridges, they also tend to enhance the birds’ tendencies to “ridge hop” their way south, thus pushing many of them southeast from the main corridor of the eastern population’s route through the central Appalachian Mountains. Here in the lower Susquehanna region, we observe these vagabonds at our numerous hawk watches which happen to be located along the outer periphery of the birds’ primary flight path. It appears that a greater percentage of these wayward eagles tend to be younger, less-experienced birds than those seen passing hawk-counting stations in the central Appalachians. Lucky for us, we get to see more of the showy juvenile and immature Golden Eagles—at least during the fall season.
In the spring, southerly breezes and the urge to “ridge hop” in a northerly direction tend to concentrate Canada-bound migrating Golden Eagles along the northernmost ridges in their Appalachian flyway. To see them, we took a short drive up the Juniata River valley to the 90,000 acres of Rothrock State Forest and Tussey Mountain Hawk Watch. During our visit there earlier this week, gusty winds from the southwest brought us an opportunity to see the elusive northbound flights of some of the members of eastern North America’s population of Golden Eagles.
Tussey Mountain Hawk Watch is located along State Route 26 atop Tussey Mountain, just south of State College, Pennsylvania. Visitors can find ample parking at the Jo Hays Vista along the west side of the road on the crest of the ridge .Looking north from Jo Hays Vista to State College and the main campus of Penn State University. Bald Eagle Mountain is in the background and behind it lies Allegheny Front and Plateau.From the Jo Hays Vista parking area, follow the Mid State Trail (orange blazes) south along the ridgetop for about a half mile to the Tussey Mountain Hawk Watch lookout.The lookout at Tussey Mountain Hawk Watch is located within a utility right-of-way with talus slopes flanking the ridgetop clearing.An interpretive sign shows a statistical graphic describing the seasonal abundance of Golden Eagle sightings at the site. The peak time: late February through early April.Tussey Mountain is the only hawk-watching station in the lower Susquehanna region staffed by an official counter to collect data during the spring migration season. You can view the daily counts at hawkcount.org. You can contribute to them by visiting the hawk watch to help scan the skies.By late morning, a small flight of Golden Eagles had commenced. Most of the birds seen at Tussey Mountain are adult or near-adult birds with dark wing linings and slightly paler flight feathers. It’s a two-toned appearance similar to that of a Turkey Vulture and there is little if any variation in the length of the flight feathers. These birds are three years of age or older, are or soon will be sexually mature, and often travel in pairs separated by a minute or two of flight time.This Golden Eagle caught our attention with its longer central tail feathers and some longer secondary feathers in the wings that create a wavy appearance. As they get older, immature eagles should become more skilled as fliers, so each new set of flight feathers is usually shorter than those they’re replacing. Based upon the characters contributing to its ragged appearance, this bird is probably in the early months of its fourth or fifth calendar year of life.Common Ravens are forever vigilant around our regional hawk watches. They can sometimes help us find otherwise hard-to-spot migratory raptors in the bright, sunny skies.Ravens really like to harass younger birds like this second or third-year Golden Eagle.Older, more stoic raptors like this adult Bald Eagle spend less time contending with the antics of the persistent ravens.One of the final sightings of the day was this magnificent Golden Eagle. Look closely and you can see evidence of some molt completed last year in the outer tail feathers and the innermost primaries in the wings. On top, there were tawny bars on the wing coverts. This bird is probably just beginning its third calendar year of life and will start replacing many more flight feathers later this spring.
For more information on the region’s hawk watches and the birds you’ll see there, be certain to click the “Hawkwatchers Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page. And for a more detailed look at how to determine the age of Golden Eagles, particularly during the autumn migration, click the “Golden Eagle Aging Chart” tab at the top of this page.
We’ve seen worse, but this winter has been particularly tough for birds and mammals in the Lower Susquehanna River Watershed. Due to the dry conditions of late summer and fall in 2024, the wild food crop of seeds, nuts, berries, and other fare has been less than average. The cold temperatures make insects hard to come by. Let’s have a look at how some of our local generalist and specialist species are faring this winter.
House Sparrows (bottom) and House Finches (top) are generalists. To survive and thrive, they are adapted to a variety of habitats and types of food. House Sparrows live almost anywhere man-made structures are found. They are true omnivores and will eat almost anything, especially if they see something else try to eat it first. The House Sparrow’s close association with humans has allowed it to become the most widespread and successful living avian dinosaur. On a cold night, they’ll take shelter either within dense vegetation alongside a building or within the structure itself. Though not nearly as cosmopolitan, the House Finch has successfully colonized much of the eastern United States after escaping from captivity as a cage bird in New York during the middle of the twentieth century. Upon being trans-located here from the arid southwest, they adapted to suburbs and farmlands consuming primarily a granivore diet of seeds supplemented with seasonally available berries. They quickly became accustomed to offerings at bird-feeding stations as well. To survive the harsh winters in the northern sections of their range, eastern populations of House Finches are developing a pattern of migration. These movements are most evident in late fall when dozens or sometimes hundreds can be seen heading south over regional hawk-counting stations.Though they require dead trees for nesting and as places to find the grubs and adult insects upon which they primarily feed, woodpeckers including the Northern Flicker are generalists, seldom passing by a supply of fruits like these Poison Ivy berries as a source of winter food. Flickers regularly visit suburban areas where they’ll drop by at bird-feeding stations for suet. During the warmer months, they are the woodpecker most frequently seen on the ground where swarms of ants garner their full attention.The Pileated Woodpecker is seldom found outside of mature forests where it digs relentlessly to remove grubs and other infestations from dead wood. But it is not a true specialist……it too finds a supply of Poison Ivy berries to be indispensable during a cold winter day.The Ruby-crowned Kinglet is a generalist, feeding mostly on insects, but also consuming small seeds and some berries, including those of Poison Ivy. It nests well to our north in tall spruces and other evergreens. During migration and in winter, the Ruby-crowned Kinglet may be found in deciduous trees, brush, and tall grass in habitats ranging from forests to parks and suburbia. This male is displaying its seldom-seen red crown.The Golden-crowned Kinglet, seen here on a Poison Ivy vine, is more of a specialist than the Ruby-crowned species, though the two will often occur in mixed groups during the winter. The Golden-crowned Kinglet nests in Spruce-Fir forests and in conifers within mixed woodlands. Even during migration, and particularly in winter, these birds are seldom found far from a stand of large evergreens within which they find shelter for the night.The Hermit Thrush’s generalist lifestyle allows it to survive cold season weather in the Lower Susquehanna River Watershed. During summer, it breeds in coniferous and mixed woods from the northern parts of our valley north into Canada and feeds primarily on worms, insects, and other arthropods. During migration and in winter, the Hermit Thrush becomes a regular visitor to deciduous forests, woody parks and suburbs, particularly where a supply of wild berries is available to supplement its diet.Iconic as it pulls earthworms from lawns during the warmer months, the generalist American Robin is fully dependent upon a crop of berries to survive winter conditions in the lower Susquehanna valley. The drought afflicted wild food crop of 2024 has led to fewer robins spending the season here and has delayed the northward push of migrating birds until the ground thaws and the earthworms make the ground rumble once again.It’s insects for the nestlings during spring and summer, then berries through the winter for the cheerful Eastern Bluebirds, another generalist species.American Crows are an excellent example of a generalist species. They’ll go anywhere to find food and they’ll eat almost anything. Like the House Sparrow and several other generalists, they adapt very well to human activity and actually thrive on it. Garbage anyone?Another career generalist is the widely worshiped White-tailed Deity, a species adapted to nearly all man-made landscapes with adequate vegetation upon which to browse. Pushed to the limit during severe weather, some individuals will consume carrion and even resort to cannibalism.You might think the Great Blue Heron is a specialist. Nope, it’s an accomplished generalist. Great blues will live, feed, and breed on almost any body of fresh or brackish water. And their diet includes almost anything that swims. In winter, you’ll even see them in fields hunting mice and voles.The Red-shouldered Hawk is a generalist with a diet ranging from amphibians and reptiles to small rodents and large insects. Mostly regarded as a species of bottomlands, they’ll frequent woodland edges, roadsides, and suburbia during the winter months.During its periodic winter visits to the region, the American Tree Sparrow feeds on seeds among the grasses and forbs of semi-open country with scattered short shrubs and trees. A generalist species, it will show up at backyard bird-feeding stations, particularly during periods of inclement weather. In summer, the American Tree Sparrow nests in tundra with growths of stunted willows and spruce and their diet includes insects as a source of protein for themselves and their young.The White-crowned Sparrow has similar winter habitat preferences to the tree sparrows……it becomes adaptable and something of a generalist when searching for food during bad winter storms.The Savannah Sparrow is an omnivore favoring insects in summer and seeds in winter. Though very closely tied to its grassland habitat year-round, snow cover can push these birds to enter woodier environs to consume fruits like these rose hips.Dusk and dawn during the short days of winter are the prime hunting times of a mammal specialist, the Short-eared Owl. Its presence in the lower Susquehanna valley is dependent on two dominant factors: extensive grassland habitat and an adequate population of the owl’s favored food, the Meadow Vole (Microtus pennsylvanicus). The Short-eared Owl’s requirements as a specialist species make finding a suitable place to live difficult. Unlike the generalist birds and mammals that often adapt to the widespread man-made disturbances in the region, populations of specialists frequently become fragmented, reduced in abundance, and subject to extirpation.The Meadow Vole is a generalist rodent that can be abundant in grasslands, early successional growth, fallow fields, marshlands, and, of course, meadows. They are primarily herbivores, but will occasionally consume insects and other arthropods. Usually nocturnal, some individuals venture out along their surface runways during daylight hours becoming vulnerable to diurnal raptors including kestrels, harriers, and buteos.A Short-eared Owl in near darkness patrolling a grassland for Meadow Voles.The eastward expansion of the Coyote (Canis latrans), a species of western North America’s grasslands and scrublands, and its progressive mixing with the Wolf (Canis lupus) in these eastern extensions of its range, has produced an expanding population of very adaptable generalists we call Eastern Coyotes (Canis latrans var.). These omnivorous canines colonized the Lower Susquehanna River Watershed during the last four decades to replace extirpated wolves as the top-tier natural predator in the region. Their primary diet includes Meadow Voles in grasslands and other small mammals along woodland edges and in successional habitats. Seasonally, they consume the berries of numerous wild plants. Slightly larger than their western ancestors, Eastern Coyotes with the admixture of Wolf genetics can subdue small ungulates. Like other apex predators, they are attracted to vulnerable prey and thus play a crucial role in culling the weak and diseased among their potential quarry species to assure the health and potential of populations of these species as long-term sources of food energy. The benefit to the prey species is however largely diluted in populous areas of the northeast; most venison consumed by Eastern Coyotes here is in the form of road kill. During periods of extended snow cover when small rodents and other foods become inaccessible, Eastern Coyotes, particularly young individuals, will wander into new areas seeking sustenance. Sometimes they venture into cities and suburbs where they explore the neighborhoods in search of garbage and pet foods placed outside the home. (Video clip courtesy of Tyler and Grace Good. Click image to view.)
Wildlife certainly has a tough time making it through the winter in the lower Susquehanna valley. Establishing and/or protecting habitat that includes plenty of year-round cover and sources of food and water can really give generalist species a better chance of survival. But remember, the goal isn’t to create unnatural concentrations of wildlife, it is instead to return the landscape surrounding us into more of a natural state. That’s why we try to use native plants as much as possible. And that’s why we try to attract not only a certain bird, mammal, or other creature, but we try to promote the development of a naturally functioning ecosystem with a food web, a diversity of pollinating plants, pollinating insects, and so on. Through this experience, we stand a better chance of understanding what it takes to graduate to the bigger job at hand—protecting, enhancing, and restoring habitats needed by specialist species. These are efforts worthy of the great resources that are sometimes needed to make them a success. It takes a mindset that goes beyond a focus upon the welfare of each individual animal to instead achieve the discipline to concentrate long-term on the projects and processes necessary to promote the health of the ecosystems within which specialist species live and breed. It sounds easier than it is—the majority of us frequently become distracted.
Being an individual from a population of a very successful generalist species is no guarantee of survival. This Eastern Gray Squirrel fell from a tall tree when the limbs became ice covered during a storm earlier this month. Just a freak accident? Maybe, but mistakes like this are often fatal in the natural world. This squirrel’s passing may seem brutal, but it provides a better opportunity for other squirrels and animals that share its food and cover requirements to make it through the winter. And those survivors that didn’t suffer such a fatal mistake or, more importantly, don’t possess a vulnerability that may have contributed to such a mishap will have a chance to pass those traits on to a new generation. This squirrel as an individual is gone, its species lives on, and may be stronger for its passing.Pennsylvania Game Commission crews maintain a grassland ecosystem for Short-eared Owls and other specialists using prescribed fire to prevent succession beyond its earliest stages. Among the additional specialist species benefiting from this management tool are Monarchs and other butterflies whose host plants survive early-season fire, but not competition with woody vines, shrubs, trees, and invasive herbaceous growth.
On the wider scale, it’s of great importance to identify and protect the existing and potential future habitats necessary for the survival of specialist species. And we’re not saying that solely for their benefit. These protection measures should probably include setting aside areas on higher ground that may become the beach intertidal zone or tidal marsh when the existing ones becomes inundated. And it may mean finally getting out of the wetlands, floodplains, and gullies to let them be the rain-absorbing, storm-buffering, water purifiers they spent millennia becoming. And it may mean it’s time to give up on building stick structures on tinderbox lands, especially hillsides and rocky outcrops with shallow, eroding soils that dry to dust every few years. We need to think ahead and stop living for the view. If you want to enjoy the view from these places, go visit and take plenty of pictures, or a video, that’s always nice, then live somewhere else. Each of these areas includes ecosystems that meet the narrow habitat requirements of many of our specialist species, and we’re building like fools in them. Then we feign victimhood and solicit pity when the calamity strikes: fires, floods, landslides, and washouts—again and again. Wouldn’t it be a whole lot smarter to build somewhere else? It may seem like a lot to do for some specialist animals, but it’s not. Because, you see, we should and can live somewhere else—they can’t.
The Allegheny Woodrat (Neotoma magister), a threatened species in Pennsylvania and a critically imperiled species in Maryland, is a habitat specialist requiring the forested rocky slopes, talus-flanked ridgetops, and caves of the Ridge and Valley Province for its nest sites and survival. Isolated populations survived within similar environs in the lower Susquehanna River valley’s Piedmont Province and on South Mountain through at least the first half of the twentieth century, but have since been extirpated. Human encroachment that fragments their habitat and promotes exposure to parasite-hosting mammals including the Raccoon (Procyon lotor), carrier of the Raccoon Roundworm (Baylisascarius procyonis), could prove fatal to remaining populations of this native mammal. (National Park Service image by Rick Olsen)The American Oystercatcher (Haematopus palliatus) is a specialist species that uses its highly adapted bill to feed on marine invertebrates including mollusks, few of which are actually oysters. Reliant upon tidal ecosystems for its survival, many of the seashore animals that make up this wader’s diet are themselves specialist species. Oystercatchers spend nearly their entire lives in tidal marshes or within the intertidal zone on beaches. They also frequent rocky jetties, particularly during high tide. This individual was photographed near the mouth of Chesapeake Bay in Northhampton County, Virginia, a location that, when the waters of the Atlantic started rising over 10,000 years ago, was the lower Susquehanna valley about 60 miles from the river’s mouth at present-day Norfolk Canyon along the edge of the continental shelf. Get the drift?
After decades of heavy manual labor, it’s time for your editor to go under the knife and have his guts put back where they belong. We hope you won’t mind if we take a little break while he behaves like this Hermit Thrush and becomes a bit of a recluse for a while. We’ll be back soon.
Here are 7 reasons why you, during the coming week or so, should consider spending some time at Willow Point overlooking the lake at the Pennsylvania Game Commission’s Middle Creek Wildlife Management Area.
REASON NUMBER ONE— Wildlife is at close quarters along the trail leading from the parking lot to Willow Point…
Eastern Gray Squirrels are common and easily seen along the edge of the woods.Eastern Bluebirds are investigating nest boxes and may presently be using them as communal roost sites during cold, windy nights.A Hermit Thrush was just one of the songbirds we found foraging along the edge of Willow Point Trail.Look carefully and you may see one or more species of woodpeckers in the mature trees. We found this Yellow-bellied Sapsucker in a maple near the trail’s terminus at the Willow Point viewing area.
REASON NUMBER TWO— A variety of waterfowl species are lingering on ice-free sections of the lake surrounding Willow Point…
Noisy flocks of Tundra Swans and Canada Geese on open water at Willow Point.American Black Ducks on a fly by.Mallard drakes near the point.A small flock of Green-winged Teal feeding among the Mallards.A flock of Northern Shovelers has been frequenting the shallows along the south side of Willow Point for at least two weeks.Common Mergansers diving for benthic fare.
REASON NUMBER THREE— Bald Eagles are conspicuous, easily seen and heard…
Bald Eagles on tree stumps in the lake.A hatch-year/juvenile Bald Eagle on a glide over Willow Point.
REASON NUMBER FOUR— Northern Harriers have been making close passes over Willow Point as they patrol Middle Creek’s grasslands while hunting voles…
A female Northern Harrier over Willow Point.A hatch-year/juvenile Northern Harrier gazing over a field of goldenrod adjacent to Willow Point.Hatch-year/juvenile Northern Harrier patrolling a field of goldenrod and preparing to pounce.A Northern Harrier buoyantly flying past Willow Point just prior to sunset.
REASON NUMBER FIVE— The annual observance of the White-tailed Deity holidays may be drawing to a close for the gasoline and gunpowder gang, but for the supreme ungulates, the rituals that lead to consummation of their unions are still ongoing…
Mystical White-tailed Deities hiding in plain sight near Willow Point.Having so far survived the ceremonies of sacrifice practiced by worshipers clad in vibrant orange attire, these divine idols agree to a more civilized ritual, a gentlemanly duel.
…then it’s off to find the fair maidens.
REASON NUMBER SIX— Sandhill Cranes are still being seen from Willow Point…
Sandhill Cranes have been spending time on dry portions of the lake bed and in grasslands and croplands to the north.
These Sandhill Cranes could depart from Middle Creek’s refuge at any time, particularly if the deep freeze returns to make feeding more difficult. You’ll want to visit soon if you want to see them.
REASON NUMBER SEVEN— The crowds that will accompany the arrival of thousands of Snow Geese in early 2025 can make visiting Willow Point a stressful experience. Visit now to see these birds and mammals at Willow Point and you might just have the place all to yourself. Then you can spend your time looking through the flocks of waterfowl and other birds for unusual new arrivals instead of wading through a sea of humanity.
White-crowned Sparrows at Middle Creek Wildlife Management Area’s Willow Point.
Each spring and fall, Purple Finches are regular migrants through the Lower Susquehanna River Watershed. Northbound movements usually peak in April and early May. During the summer, these birds nest primarily in cool coniferous forests to our north. Then, in October and November each year, they make another local appearance on their way to wintering grounds in the southeastern United States. A significant population of Purple Finches remains to our north through the colder months, inhabiting spruce-pine and mixed forests from the Great Lakes east through New England and southeastern Canada. This population can be irruptive, moving south in conspicuous numbers to escape inclement weather, food shortages, and other environmental conditions. Every few years, these irruptive birds can be found visiting suburbs, parks, and feeding stations—sometimes lingering in areas not often visited by Purple Finches. Right now, Purple Finches in flocks larger than those that moved through earlier in the fall are being seen throughout the lower Susquehanna valley. Snow and blustery weather to our north may be prompting these birds to shift south for a visit. Here are some looks at members of a gathering of more than four dozen Purple Finches we’ve been watching in Lebanon County this month…
Purple Finches are easily distinguished from House Finches by their notched tails, darker streaking, and well-defined facial markings. Though most frequently found in proximity to conifers, they also visit native deciduous trees and shrubs to snack on berries, seeds, and buds. Purple Finches can be particularly fond of maple, birch, poplar, sumac, and viburnum.Adult male Purple Finches are unmistakable in their wine-colored plumage.Purple Finches join a Dark-eyed Junco, a White-throated Sparrow, and a Black-capped Chickadee at a feeding station.Purple Finches eating black oil sunflower seed.A male Purple Finch in successional forest edge habitat consumes seeds from a dried stand of goldenrod.Purple Finches with juncos and Northern Cardinals.Purple Finches filling up on supplemental foods.
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.
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.
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.
Another arrival from the northern forests, the petite 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.
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.
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 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)
In the forests and woodlots of the lower Susquehanna watershed, the Black Gum, also known as the Black Tupelo, is always the first of our native trees to pop with autumn color. Its crimson leaves glow in an otherwise green landscape to help lure hungry birds including waxwings, American Robins, and Pileated Woodpeckers to its soon-to-be-ripe berries. The seeds contained in the fruit are thus well-distributed as a by-product of this avian feast. While not among the most massive of our trees, the Black Gum can live for over five hundred years, an age not exceeded by any other non-clonal indigenous flowering plant.
Do you recall our “Photo of the Day” from seven months ago…
Here’s something to look forward to in the new year. The good citizens of East Donegal Township in Lancaster County have partnered with Alliance for the Chesapeake Bay to establish an extensive wildflower meadow on what had been a mowed field of turf grass at Riverside Park in the Susquehanna floodplain near Marietta. As the photo shows, the lawn plants have been eliminated in preparation for seeding with a diverse assortment of native grasses and wildflowers to provide habitat for birds and pollinators including butterflies, bees, and other insects. Once established, the meadow’s extensive vegetative growth will help reduce stormwater runoff by better infiltrating rainfall to recharge the aquifer. During flood events, the plantings will provide soil stabilization and increase the ability of the acreage to uptake nutrients, thus reducing the negative impact of major storms on the quality of water in the river and in Chesapeake Bay. Check the project’s progress by stopping by from time to time in 2024!
Well, here’s what that site looks like today…
The wildflowers, thousands of them, are now in bloom!Black-eyed Susan and Blue Vervain (Verbena hastata) dominate the assortment currently in flower.
And there are pollinating insects galore, most notably butterflies…
A Cabbage White collecting nectar on Blue Vervain.A Clouded or Orange Sulphur among the grasses in the meadow.A Silver-spotted Skipper.The Least Skipper is our tiniest butterfly.The Little Glassywing (Vernia verna), this one feeding on vervain nectar, deposits its eggs on Purpletop grass, which then functions as the host plant for this butterfly’s larvae.A Summer Azure (Celastrina neglecta) feeding on the nectar of a Black-eyed Susan.A Common Buckeye on a “Gloriosa Daisy”, a showy, large-flowered cultivar of Black-eyed Susan.A Red-winged Blackbird with a caterpillar found among the meadow’s lush growth.An Eastern Tiger Swallowtail on Blue Vervain. Nearby Yellow (Tulip) Poplars and other trees serve as host plants for this butterfly’s larvae.The black morph of the Eastern Tiger Swallowtail shows subdued shading in the wings that closely resembles the brilliant color patterns of the more familiar yellow form.The Sachem, this one visiting a Black-eyed Susan, is a variable species with a range that normally lies south of the 40th parallel, the line of latitude that intersects the Susquehanna in the area of the Conejohela Flats at Washington Boro.A Sachem visiting the blooms of Oxeye sunflower. During recent weeks, scorching winds from the south and southwest have transported an abundance of these vagrant skippers into the lower Susquehanna valley and beyond.A male Sachem approaching the bloom of a “Gloriosa Daisy”. Miles north of the 40th parallel, wandering Sachems are currently the most numerous of the butterflies at the Riverfront Park wildflower meadow.Here and there among the meadow’s plantings we noticed one of our favorites starting to flower, the Partridge Pea.Partridge Pea happens to be a host plant for another vagrant from the south, the big, lime-yellow Cloudless Sulphur. We saw at least half a dozen patrolling the meadow.The stars of the show are the Zebra Swallowtails, gorgeous butterflies that rely on stands of native Common Paw-paw trees in the river floodplain to host their eggs and larvae.The red-white-and-blue underside of a Zebra Swallowtail.WOW!
Why on earth would anyone waste their time, energy, and money mowing grass when they could have this? Won’t you please consider committing graminicide this fall? That’s right, kill that lawn—at least the majority of it. Then visit the Ernst Seed website, buy some “Native Northeast Wildlflower Mix” and/or other blends, and get your meadow planted in time for the 2025 growing season. Just think of all the new kinds of native plants and animals you’ll be seeing. It could change your life as well as theirs.
A Snowberry Clearwing (Hemaris diffinis), more commonly known as a hummingbird moth, visits the flowers of Blue Vervain in the Riverfront Park wildflower meadow.
By mid-summer, many birds exhibit less-than-stellar appearance. Juveniles have just left the nest and although their plumage is completely fresh, it may look drab compared to the feathers the bird will sport upon reaching adulthood. Their parents, having completed the stressful tasks of building nests and raising a new generation, now enter a state of molt to replace all or some of their adornment. Now is a fortuitous time for these mature birds to exchange old feathers for new—food is plentiful and the need to keep warm and fly long distances is at a minimum. Besides, they really don’t have to impress anyone with their beauty during summer vacation.
Following the break in the heat wave during recent days, activity at the headquarters feeders has increased significantly. We took notice that many of our guests are looking a little rough around the edges.
Having started their nesting cycle in February, most Mourning Doves including this adult male are nearly done molting by mid-summer. They are the exception.This juvenile American Robin has acquired its first full set of flight feathers and will, in coming weeks, begin replacing the spotted plumage to more closely resemble an adult bird.This adult male Northern Cardinal in worn plumage is still tending to the needs of fledged young, but is nevertheless in the early stages of molt.This juvenile Northern Cardinal will not only acquire brighter red feathers as an adult, but its bill will turn red as well.This actively molting Carolina Chickadee shows pin feathers in the wings and is balding rather profusely.This Blue Jay has gone beyond having its feathers ruffled, but it’ll be good as new by the time autumn migration rolls around in September.This drab brown bird is a juvenile European Starling. While its first set of feathers looks complete, it has a big problem. It lost its left eye and has trouble keeping up with a flock of its peers that have been roaming the area. A predator will quickly notice this young bird’s vulnerabilities.A juvenile Downy Woodpecker in a dull, streaky, almost dirty-looking, first plumage. Unlike the adult male which has a red patch on the back of its head, the juvenile Downy Woodpecker has a mottled red crown.An adult female Downy Woodpecker beginning to molt its heavily worn, year-old feathers.Mid-summer is prime time for discovering post-breeding wanders. These are birds that spend the time between the end of nesting season and the fall migration roaming the countryside and sometimes visiting areas outside their more traditional habitats and/or native ranges. For the past two days, this bird, a Hairy Woodpecker, has strayed from a mature woodland into urban environs to visit the garden at susquehannawildlife.net headquarters. It’s our first record of one here.Not yet a lot of molt among the American Goldfinches. Why? Well, they’re late-season breeders and are only now in the midst of their nesting cycle. They begin shedding feathers and losing that brilliant color sometime in late August, just as the last of this year’s young are being fledged.
Think of all the opportunities mid-summer offers. It’s a good time to get outdoors to have a look at all the young animals that are exploring their world for the first time. Birds and other wildlife are at their greatest abundance of the year right now, so your chance to see new things is at its peak. And the phenomenon of post-breeding wandering always raises the possibility of a surprise or two—maybe even a rarity. Be cool and good luck!
You’ve probably never noticed the Acadian Flycatcher (Empidonax virescens). This small Neotropical songbird arrives in the Lower Susquehanna River Watershed during mid-May to breed in the dense shade of mature forests, often along steep slopes adjacent to a brook or creek. It’s quick, sneezy song—“pit-see” or “wee-seet”—heard emanating from the shadows of the woodland understory is often the first and only sign of their presence.
Of the five species of similar-looking Empidonax flycatchers that regularly occur in our region, the Acadian is the only one to nest in the forest interior. These insectivores shy away from edge habitat and clearings that disturb the closed canopy of mature trees.
One of the more fascinating habits of the Acadian Flycatcher is their selection of a nesting location. While many species try to conceal their nests in tree cavities, dense foliage, or some other form of cover, this clever songbird constructs a cup using tiny twigs and leaves and places it near the end of a small branch on a small tree. The nest is sometimes very easily seen, but for climbing scroungers looking to plunder eggs or helpless young birds, it’s practically out of reach.
A female Acadian Flycatcher on its nest incubating eggs.The white arrow points to the Acadian Flycatcher nest seen in the previous image. The dark-colored limb appears close, but this nest is perched precariously close to the end of a leafy branch and is hanging free and clear above the stream. When leaving the nest, the young birds that are destined to survive must avoid a tumble into the waterway.
To guard against airborne threats, Acadian Flycatcher parents are vigilant defenders of the space around their nest.
When this curious juvenile Carolina Chickadee wandered into the flycatcher’s nest tree……mom came out fighting! It may be an overreaction, but nesting birds often have a zero-tolerance policy for invaders within their “zone”.
Moments later, things settle down and the waiting continues…
Back on the nest, mom, the eggs, and eventually the young will spend the next several weeks riding the wind atop this flimsy branch in their shady forest home.
A nesting Grasshopper Sparrow surveys the warm-season grasslands at Middle Creek Wildlife Management Area. Minutes later, this evening’s thundershower sent everyone and everything seeking cover.
During the past week, we’ve been exploring wooded slopes around the lower Susquehanna region in search of recently arrived Neotropical birds—particularly those migrants that are singing on breeding territories and will stay to nest. Coincidentally, we noticed a good diversity of species in areas where tent caterpillar nests were apparent.
The conspicuous nest of the Eastern Tent Caterpillar (Malacosoma americanum), a native species of moth. The first instar of the larval caterpillars hatch in early spring from egg masses laid on the limbs of the host tree by an adult female moth during the previous spring. Soon after they begin feeding on the host tree’s first tender shoots, these tiny, seldom-noticed larvae start communal construction of a silk tent to act as a shelter and greenhouse-like solar collector that will both provide protection from the elements and expedite their growth.The familiar last instar of the Eastern Tent Caterpillar is the most consumptive stage of the animal’s life. After feeding in the treetops, they will descend to the ground and seek a sheltered location to pupate. Adult moths emerge in several weeks to take to the air, mate, and produce eggs to be deposited on a host tree for hatching next year. The favorite host tree in forests of the Lower Susquehanna River Watershed: native Black Cherry.
Here’s a sample of the variety of Neotropical migrants we found in areas impacted by Eastern Tent Caterpillars. All are arboreal insectivores, birds that feed among the foliage of trees and shrubs searching mostly for insects, their larvae, and their eggs.
The Yellow-throated Vireo nests, feeds, and spends the majority of its time feeding among canopy foliage.The Eastern Wood-Pewee is a flycatcher found in mature woodlands. It feeds not only among the limbs and leaves, but is an aerial predator as well.The Northern Parula nests in mature forests along rivers and on mountainsides, particularly where mature trees are draped with thick vines.The Hooded Warbler (Setophaga citrina) is found among thick understory growth on forested slopes.The Ovenbird builds a domed, oven-like nest on the ground and forages in the canopy.The Kentucky Warbler (Geothlypis formosa) nests in woodland undergrowth, often near steep, forested slopes.The Worm-eating Warbler (Helmitheros vermivorum) nests among woody understory growth on forested hillsides.The Scarlet Tanager is often difficult to observe because of its affinity for the canopy of mature forest trees.
In the locations where these photographs were taken, ground-feeding birds, including those species that would normally be common in these habitats, were absent. There were no Gray Catbirds, Carolina Wrens, American Robins or other thrushes seen or heard. One might infer that the arboreal insectivorous birds chose to establish nesting territories where they did largely due to the presence of an abundance of tent caterpillars as a potential food source for their young. That could very well be true—but consider timing.
Already Gone- By the time Neotropical migrants arrive in our area, the larval stages of the Eastern Tent Caterpillar’s life cycle are already coming to an end. The nests that these native insects constructed to capture the energy of the springtime sun have allowed the larvae to exit and browse foliage when conditions were suitable, then return for shelter when they were not. While inside, the larvae could move among the chambers of their structure to find locations with a temperature that best suited their needs. Therein the solar heating and communal warmth sped up digestion and growth.Eastern Tent Caterpillar larvae are now in their bristly final-instar stage and the majority have already moved to the ground to each seek a place to pupate and metamorphose into an adult moth. Arboreal Neotropical birds have scarcely had a chance to feed upon them, and ground-feeding species seem to lack any temptation. As for the adult moths, they fly only at night and live for just one day, offering little in the way of food for aerial, arboreal, or ground-feeding birds.Having left arboreal environs, Eastern Tent Caterpillar larvae are now food for ground-feeding birds like our resident Wild Turkeys. They need only get past the bristly hairs on the caterpillar’s back and the foul taste that may result from its limited diet of cyanogenic Black Cherry leaves.The arboreal Yellow-billed Cuckoo (seen here) and its close relative the Black-billed Cuckoo (Coccyzus erythropthalmus) are the two species of birds in our area known to regularly feed on bristly tent caterpillars. But having just arrived from the tropics to nest, they’ll need to rely on other insects and their larvae as sources of food for their young.Final-instar Eastern Tent Caterpillars often defoliate Black Cherry trees before moving to the ground to pupate. Their timing allows them to feed on the fresh foliage while it is still young and tender, and to largely avoid becoming food for the waves of Neotropical birds that arrive in the lower Susquehanna basin in May.
So why do we find this admirable variety of Neotropical bird species nesting in locations with tent caterpillars? Perhaps it’s a matter of suitable topography, an appropriate variety of native trees and shrubs, and an attractive opening in the forest.
An American Redstart singing in a Black Cherry. Unlike others in the vicinity, this tree nestled among several very large Eastern White Pines showed no signs of tent caterpillar activity. It may be that for one reason or another, no adult female moth deposited her eggs on this particular tree. During our visits, Black Cherry was but one of the diverse variety of native trees and shrubs found growing on the sloping topography that created attractive habitat for the nesting birds we found. We happened to notice that a majority, but not all, of those Black Cherry trees were impacted by Eastern Tent Caterpillars.The end of the Eastern Tent Caterpillar’s larval surge may spell the end of their nests for the year, but it’s not the end for the Black Cherry and other host trees in the Prunus (cherry) and Malus (apple) genera. Because it’s still early in the season, they have plenty of time to re-leaf and many will still flower and produce fruit. Those flowers and foliage will attract numerous other insects (including pollinators) that benefit breeding birds.The Blue-winged Warbler inhabits shrubby breaks in the forest such as this utility right-of-way where Black Cherry trees have sprouted after their seeds arrived in waste deposited by fruit-eating (frugivorous) birds. Already attractive to a variety of insectivores, these openings soon lure egg-laying Eastern Tent Caterpillar moths to the cherry trees growing therein. Even in dense forest, a small clearing created by a cluster of dead trees makes good bird habitat and will sooner or later be visited by fruit-eating species that will inadvertently sow seeds of Black Cherry, starting yet another stand of host trees for Eastern Tent Caterpillars. It’s the gap in the forest that often attracts the birds, some of which plant the host trees, which sometimes entice Eastern Tent Caterpillar moths to lay their eggs.Adapt and Reuse- A Red-eyed Vireo visits an Eastern Tent Caterpillar nest……and ignores the few remaining occupants that could easily be seized to instead collect silk to reinforce its own nest.
Here in the Lower Susquehanna River Watershed, the presence of Eastern Tent Caterpillar nests can often be an indicator of a woodland opening, natural or man-made, that is being reforested by Black Cherry and other plants which improve the botanical richness of the site. For numerous migratory Neotropical species seeking favorable places to nest and raise young, these regenerative areas and the forests surrounding them can be ideal habitat. For us, they can be great places to see and hear colorful birds.
Our Lucky Break- This Scarlet Tanager descended from the treetops to feed on spiders in a small forest clearing.
The rain and clouds have at last departed. With blue skies and sunshine to remind us just how wonderful a spring afternoon can be, we took a stroll at Memorial Lake State Park in Lebanon County, Pennsylvania, to look for some migratory birds.
Though running just a few days later than usual, Indigo Buntings have arrived to begin nesting.This Common Loon dropped by Memorial Lake during a storm several days ago and decided to stay awhile. It’s a species that winters in oceanic waters along the Atlantic seaboard and nests on glacial lakes to our north.Because of the low level of turbidity in Memorial Lake, visibility is good enough to allow this benthic feeder an opportunity to see food before expending energy to dive down and retrieve it. Favorable foraging conditions might be part of the reason this bird is hanging around.Clear Water- Memorial Lake is one of the few man-made lakes in the Lower Susquehanna River Watershed to be appropriately vegetated with an abundance of submerged, floating, and emergent plants. As a result, the water from Indiantown Run that passes through the impoundment is minimally impacted by nutrient loads and the algal blooms they can cause. Buffers of woody and herbaceous growth along the lake’s shorelines provide additional nutrient sequestering and help prevent soil erosion and siltation.The breeding season has begun for Neotropical migrants including this Baltimore Oriole, which we found defending a nesting territory in a stand of Black Walnut trees.Along the edge of the lake, this Orchard Oriole and its mate were in yet another stand of tall walnut trees.Early in the season and early in the day, we started seeing Common Nighthawks flying above wooded areas north of the lake at 4 o’clock this afternoon. After all the raw and inclement weather they’ve experienced in recent days, the warm afternoon was probably their first opportunity to feed on flying insects in quite a while.Early birds, Common Nighthawks feeding at 4 P.M.
What? You thought we were gonna drop in on Maryland’s largest city for a couple of ball games and some oysters, clams, and crab cakes—not likely.
