Warblers (Parulidae) – LIFE IN THE LOWER SUSQUEHANNA RIVER WATERSHED

October 10, 2025

Changes Following the Season’s First Frost

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

Unlike their close relatives the Tree Swallows, which include berries as well as invertebrates in their diet, Northern Rough-winged Swallows are strictly insectivores and will find it necessary to promptly move south to assure a frost-free environment where they can secure an adequate supply of food. Their one alternative: find a local sewage treatment plant where warm water attracts populations of flying insects through the remainder of autumn and maybe into winter.

Warblers too are insect eaters. Look for most of our dozens of species to evacuate the area in coming days and leave behind only the Yellow-rumped Warbler, another bird with a fondness for berries during cold weather. Into the winter months, they remain in small numbers in habitats with an abundant supply of berries like Poison Ivy, holly, wild grape, bittersweet, and Eastern Red Cedar. For lingering Yellow-rumped Warblers, thickets of cedars and other evergreens provide essential protection from frigid nighttime winds.

This Eastern Chipmunk will soon feel the pinch. Instead of eating the sweet, fruity portions of Mile-a-minute Weed berries, it’ll have to get serious about stocking its den with larger seeds, acorns, hickory nuts, and other foods to snack on through the winter. Better get busy, little friend!

September 22, 2025September 22, 2025

Migrants Seeking Shelter to Weather the Storm

Less than ideal flying conditions can cause some of our migrating birds to make landfall in unusual places. Clouds and gloom caused a couple of travelers to pay an unexpected visit to the headquarters garden earlier today.

Here in our urban oasis, this Northern Parula was our first warbler of the season. We noticed it gleaning small insects from the leaves and stems of the taller trees.

It was joined by this Red-breasted Nuthatch near a trickle of water at one of the ponds.

Our resident Carolina Chickadees made good foraging companions for our temporary guests.

Be sure to keep an eye open for visiting migrants in your favorite garden or park during the overcast and rainy days ahead. You never know what might drop by.

September 12, 2025September 12, 2025

Tropical Treats and an Early Surprise

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

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

A Tennessee Warbler peers from the cover of a Staghorn Sumac (Rhus typhina), a small native tree which is not, as many assume, a poisonous plant. Staghorn Sumac is in fact an excellent wildlife species with brilliant autumn colors.

Though its breeding season has come to an end, this southbound Yellow-throated Vireo was found singing its heart out in the limbs of a Staghorn Sumac early this morning.

Black-throated Green Warblers are particularly numerous right now. To see them, visit a ridgetop forest clearing at sunrise.

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

Southbound flights of Ruby-throated Hummingbirds are reaching their peak this week with chilly temperatures hustling them along. Remember to keep your feeders clean and your nectar fresh through at least early October; they may really need the supplemental energy.

Migrating Broad-winged Hawks, sometimes traveling in large flocks known as kettles, seek out thermal updrafts to gain altitude before gliding away on a southwest heading bound for Houston, Texas. Once there, they’ll make a turn to the south and follow the gulf coastline toward the tropics for winter.

While on the crest, you might notice that the Neotropicals aren’t the only bird species heading through. Migrants like this Sharp-shinned Hawk are beginning to show up in increasing numbers with a peak expected in about two to three weeks.

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

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

June 2, 2025June 3, 2025

Photographs in Living Color: Black and White is Beautiful

Here at susquehannawildlife.net headquarters, we really enjoy looking back in time at old black-and-white pictures. We even have an old black-and-white television that still operates quite well. But on a nice late-spring day, there’s no sense sitting around looking at that stuff when we could be outside tracking down some sightings of a few wonderful animals.

American Toad Tadpoles — American Toad tadpoles have hatched from clusters of eggs deposited in this wet roadside ditch furnished with a clean supply of runoff filtered through a wide shoulder of early successional growth. Recent rains have kept their vernal nursery flooded, giving them the time they need to quickly mature into tiny toads and hop away before scorching summer heat dries up their natal home.

Water Striders mating. — Weekend rains and creek flooding haven’t stopped these Water Striders from pairing up to begin their breeding cycle.

Around streams, lakes, ponds, and wetlands, the Common Whitetail is one of our most conspicuous dragonflies.

Now that’s what we call a big beautiful bill, on a Great Blue Heron stalking fish.

These mating Golden-backed Snipe Flies (Chrysopilus thoracicus) are predatory insects, as are their larvae. They are most frequently found in bottomland woods.

About three feet in length, this Eastern Ratsnake is unusual because it still shows conspicuous remnants of the diamond-patterned markings it sported as a juvenile.

The plumage of the Black-and-white Warbler lacks any of the vibrant colors found in the rainbow, but is nevertheless strikingly beautiful.

May 25, 2025May 25, 2025

Late May Action in the Forest

Here’s a short preview of some of the finds you can expect during an outing in the Lower Susquehanna River Watershed’s forests this week…

The Mountain Laurel, designated as Pennsylvania’s state flower, is now in bloom.

Mountain Laurel Flower Buds — The buds of the Mountain Laurel remind us of a sugary frosting freshly squeezed from a baker’s pastry bag.

Mountain Laurel Flowers — The flowers of the Mountain Laurel, an evergreen understory shrub, invite pollinators to stop by for a sweet treat.

Little Wood-Satyrs (Megisto cymela) are patrolling forest edges looking for mates and, to host their eggs and larvae, the stands of grasses they find most suitable.

Many of the species of small butterflies we call skippers are now active. The Zabulon Skipper can be found patrolling grassy forest edges, particularly near streams, ponds, and wetlands.

Among the showiest of our butterflies, the Red-spotted Purple (Limenitis arthemis astyanax) is seen here on the leaves of a Black Cherry, its favored host plant.

Butterfly observers will do well to pay a visit to the new Susquehanna Riverlands State Park on Furnace Road north of Hellam in York County, Pennsylvania.

Trail to Schull's Rock Overlook — Upon arrival at Susquehanna Riverlands, drive back the gravel road for about a mile to the parking area at the edge of the agricultural field. Then, hike the trail through the woods and farm hedgerow to the Schull’s Rock overlook on the river. In the forests along this route, the understory is dominated by colonial stands of Common Pawpaw trees.

Along the lookout trail to Schull’s Rock, the Common Pawpaws’ large leaves help them to shade out potentially fast-growing competition. In proper growing situations, pawpaws develop clonal suckers that mature over time to create colonial stands of a single genetic plant.

Common Pawpaw understory. — A Common Pawpaw understory along the approach to Schull’s Rock.

During our recent visit to Schull’s Rock, dozens of Zebra Swallowtails were seen along the trail, many in the vicinity of their sole host plant, the Common Pawpaw. But even more were observed along the edges of the fields and woods where nectar sources like this Multiflora Rose were being visited by numbers of butterflies we normally see only among abundant species like Cabbage Whites. Absolutely amazing!

Scull's Rock Overlook — And the view of the Susquehanna and the Shock’s Mills railroad bridge at the mouth of Codorus Creek is pretty good too!

Common Pawpaw and Hooded Warbler — You can look for colonial stands of Common Pawpaw at other parks and preserves along the lower Susquehanna as well. Birds like this Hooded Warbler can sometimes be found among them in mature riparian forests along the steep slopes of the river gorge.

Common Pawpaw and Baltimore Oriole — A Baltimore Oriole in a Common Pawpaw along a forest edge.

Meanwhile in the treetops, the spring thrust of Neotropical migrants is drawing to a close. The Blackpoll Warbler is typically one of the last to transit the lower Susquehanna valley on its way to northern coniferous forests for summer. They’ve had an unusually protracted movement through the region this spring, the earliest individuals reported during late April. Though very difficult to see in the canopy of the mature trees where it feeds and sings, hearing one is often a benchmark for senior birders each spring. Older observers have often said of the Blackpoll Warbler’s high-pitched song, a rapid series of insect-like staccato “tseet” notes, that it was the first they could no longer detect as their ears started losing sensitivity.

In many tracts along the lower Susquehanna this spring, the American Redstart is turning out to be the most common nesting warbler. Conditions favoring their reproductive success in recent cycles, as well as good survival rates during their migrations and stays on wintering grounds, have filled many lowland forests with redstart songs in 2025. Is this the start of a trend or just an exceptionally good year? Time will tell.

Yet one more reason for a stroll in local forests this week is the chance to see and hear the Rose-breasted Grosbeak. Look for these Neotropical relatives of the cardinal nesting on territories in mature stands of deciduous trees like this Yellow Poplar, a species also known as the Tuliptree.

They spend nearly all their time among the canopy foliage of the largest timber…

May 19, 2025May 26, 2025

Back in the Day: Down on the Farm

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

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

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

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

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

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

Always found nesting under the forebay of the barn, the Barn Swallow relentlessly pursued flying insects over the pond and meadow.

Eastern Meadowlarks arrived during March and April to begin nesting in their namesake. Their song, “spring-of-the-year”, heralded the new season.

Arriving in meadows and pastures during early May, the Eastern Kingbird provided for its nestlings by ambushing a variety of flying insects. By August, congregations of these birds could be found gathering along ponds and streams ahead of their fall migration.

In the cherry grove down by the creek, the Orchard Oriole would be singing incessantly to defend its territory.

Normally seed eaters through the colder months, American Goldfinches would regularly find a source of protein in the occupants of Eastern Tent Caterpillar nests.

Along the wet margins of the creek, Yellow Warblers would nest in the shrubs and small trees.

The “Traill’s Flycatcher” was a familiar find in low-lying areas of successional shrubs and small trees. Today, “Traill’s Flycatcher” is recognized as two distinct species, the Alder Flycatcher (Empidonax alnorum) and the Willow Flycatcher. In the lower Susquehanna valley, the latter (seen here) is by far the most common of the two.

During the nineteenth century, Eastern Bluebirds became a rarity on lower Susquehanna farms due to a combination of factors: pesticide (DDT) use, habitat loss, and competition with other birds for nest sites. The species saw a resurgence beginning in the 1970s with discontinuation of DDT applications and widespread provision of nesting boxes. Around human habitations, competition with invasive House Sparrows continues to be detrimental to their success.

Purple Martins and Tree Swallows — Purple Martins suffered a similar fate to the bluebirds. The potential for their recovery remains dubious and they continue to be very local breeders, fussy about selection of suitable man-made provisions for nesting. After considerable effort, Purple Martins have at last been attracted to nest in the condos placed for their use at Middle Creek Wildlife Management Area. In the artificial gourds, there are nesting Tree Swallows, a species which also benefits from the placement of boxes intended for bluebirds.

Abandoned fields and other successional habitats were and continue to be favored homes for Field Sparrows.

At almost any time of year, roving bands of Cedar Waxwings would suddenly visit old field habitat looking for berries among the shrubs and other pioneering woody growth. In early summer, after most species have already hatched their young, nesting would commence and these fruit eaters would transform into accomplished fly catchers.

During the twentieth century prior to the 1980s, Ring-necked Pheasant populations in the Lower Susquehanna River Watershed were comprised of breeding descendants of introduced birds supplemented by additional releases to maintain numbers sufficient for hunting. Year-round populations did and can reside in mosaic landscapes of early successional and grassland habitats, the latter including hay fields left unmowed through the nesting season.

Red-winged Blackbirds have always been a fixture of hay fields and meadows on farms. While the increase in mowing frequency has reduced their nesting success, they have persevered as a species by nesting earlier than other birds and by utilizing other landscape features such as densely vegetated stormwater basins for breeding sites.

Do you recall the last time you saw a Bobolink nesting in a hay field near you? Arriving in early May as a Neotropical migrant, the Bobolink requires a cool-season grassland such as hay field through at least July to complete its nesting cycle. Even earlier this century, we remember nesting Bobolinks being more widespread on farms throughout the region. Now, you almost have to go to Middle Creek if you want to see them.

Formerly more widespread in hay fields throughout the lower Susquehanna valley, the native Grasshopper Sparrow is yet another species falling victim to early mowing and intensive farming.

Cool-season Grasses — **Beautiful cool-season grasses waving in the spring breeze.** Meadows and hay fields can be managed to function as cool-season grasslands to provide nesting opportunities for many of the species we used to find down on the farm.

May 13, 2025May 13, 2025

Nest Builders at Work

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

Pileated Woodpecker Excavating Nest — Many of our year-round resident bird species get a head start on the breeding season as cavity nesters. Some of these mated pairs use naturally occurring hollows, while still others take advantage of the voids left vacant by the more industrious previous occupants. Woodpeckers in particular are responsible for excavating many of the cavities that are later used as homes by a variety of birds and mammals to both rear their young and provide winter shelter. Pileated Woodpeckers, like other members of the family Picidae, have an almost mystic ability to locate diseased or insect-infested trees for selection as feeding and nesting sites. In this composite image, a pair is seen already working on a potential nursery during mid-January. After use by the woodpeckers, abandoned cavities of this size can become nesting sites for a variety of animals including bees, small owls, Great Crested Flycatchers, Wood Ducks, Hooded Mergansers, and squirrels.

Downy Woodpecker at Nest — After use as a nesting site, a void excavated by Downy Woodpeckers can be occupied in subsequent years by chickadees, titmice, nuthatches, wrens, and other cavity-dwelling species.

Muskrat with Leafy Twig — This Muskrat (*Ondatra zibethicus)* with a leafy twig in tow takes advantage of spring’s new growth to construct or repair its house,…

Muskrat House — A Muskrat house in March. In the absence of leafy twigs, dried cattail stems will suffice. As it ages and decays, the house’s organic matter generates heat and makes an ideal location for turtles to deposit and hatch their eggs.

Soon after Neotropical migrants begin arriving in the forests of the lower Susquehanna watershed, they begin constructing their nests. The majority of these species build “outdoors”, not within the confines of a tree cavity. Here we see a Wood Thrush with its bill full of dried leaves and other materials…

Wood Thrush Nest — …ready to line the cup of its nest in the fork of a small understory tree.

Though it often arrives during early April after spending the winter in sub-tropical and even some temperate climes, the Blue-gray Gnatcatcher must wait to start construction of its nest until many of the Neotropical migrants arrive in early May.

Blue-gray Gnatcatchers — Back at the nest site…

Baltimore Oriole with Nesting Material — Baltimore Orioles weave one the most unique nests of any species occurring in eastern North America.

Baltimore Oriole Nest — Unfortunately for them, man-made litter can often seem to be the ideal material for binding the nest together. In an area only sporadically visited by anglers, this oriole had no trouble finding lots of monofilament fishing line, trash that can fatally entangle both adult and young birds of any species. If you see any fishing line at all, please pick it up and dispose of it properly.

Baltimore Oriole — Always keep an eye open for fishing line and get it before the birds do!

Like many other avians, male Brown-headed Cowbirds are now relentlessly pursuing females of their kind.

Watching and waiting. The Indigo Bunting evades cowbird parasitism by first recognizing the invader’s egg. They then either add a new layer of nest lining over it or they abandon the nest completely and construct a new one. Some patient buntings may delay their breeding cycle until after cowbird courting behavior ceases in coming weeks.

May 9, 2025May 26, 2025

Their Songs Give Them Away

After repeatedly hearing the songs of these Neotropical migrants from among the foliage, we were finally able to get a look at them—but it required persistent effort.

Often found closer to the ground among shrubs and small trees, this Magnolia Warbler was a challenge to find in the upper reaches of a Chestnut Oak.

Despite its status as probably the most common Neotropical songbird to nest in the deciduous woodlands of the lower Susquehanna valley, the Red-eyed Vireo is nevertheless notoriously difficult to locate among the leaves.

The Ovenbird spends much of its time on the forest floor where it builds a domed, oven-like nest.

The Worm-eating Warbler nests in understory thickets on steep forested slopes. Its rich chipping song is often the only indication of its presence.

Warbling Vireos nest near streams or other bodies of water in large deciduous trees like this Northern Hackberry.

Gray Catbirds are abundant in shrubby gardens and thickets. Most will come out of hiding to investigate disturbances like an observer making a pishing sound.

Another inhabitant of brushy successional growth is the Common Yellowthroat. It too is curious and responds quickly to squeaky sounds made by human visitors to their home ground.

The Yellow-breasted Chat is a bird of early successional growth. To establish and defend a breeding territory, this one adopted a perch along the edge of a woodlands overlooking a field in which prescribed fire was administered less than two months ago.

Sometimes we have to count ourselves lucky if we see just one in five, ten, or even twenty of the birds we hear in the cover of the forest canopy or thicket. But that’s what makes this time of year so rewarding for the dedicated observer. The more time you spend out there, the more you’ll eventually discover. See you afield!

A singing Scarlet Tanager lurking in the shade of an oak.

May 6, 2025May 6, 2025

Singing in the Rain

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

Utility Right-of-way with Successional Habitat — We hiked this utility right-of-way to the north of a heavy thunderstorm and found plenty of activity in the shrubby successional habitat there.

Prior to the implementation of the intensive manicuring practices we see currently applied to most utility right-of-ways, shrubby thickets filled miles of these linear corridors to create a webbed network of early successional growth throughout the lower Susquehanna valley. Loss of this specialized habitat has led to the almost total elimination of the formerly common Blue-winged Warbler as a breeding species here.

Another Neotropical species that nests in successional thickets is the Prairie Warbler (Setophaga discolor), seen here during one of this morning’s downpours.

The Hooded Warbler is fond of wooded thickets along the edge of forested land such as those in the Third/Stony Mountain utility right-of-way.

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

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

May 2, 2025May 3, 2025

Fresh Foliage and Plumes

Despite what seemed to be a chilly early spring, the bright green leaves that unfold to close the canopy of our deciduous forests were dense and casting shade by the last days of April. For northbound migrants, this fresh foliage provides the cover they need for foraging, resting, and, for those that will stick around to breed in the lower Susquehanna valley, nesting.

We recall many occasions when sparse foliage during the first days of May seemed to delay the big push of Neotropical species, but the seasonal arrival of these birds in 2025 is thus far mostly ahead of schedule. This absence of delay is due in part to the lushness of the oaks. Some stands have not only leafed out, but are finished flowering and have added up to 12 inches of new branch growth. We spent these early hours of May among the oaks. Here’s a look at the Neotropical migrants and other species we found…

Dozens of species of Neotropical warblers have arrived in the Lower Susquehanna River Watershed. Some will nest locally while others will continue along flight paths that will ultimately take them far to our north. We spotted this Cape May Warbler in the upper reaches of a Northern Red Oak feeding among its spent flowers. Its destination: the spruce forests of northern New England and Canada.

This young Red-tailed Hawk has survived its first winter. It appears to have learned from experience how to hunt from advantageous locations such as this Chestnut Oak along a utility right-of-way where prey may include numerous squirrels as well as mice and other small mammals.

We were taking a break beneath this Pin Oak when suddenly an American Kestrel arrived to begin scolding a trespasser that was straying a bit too close to its nest;…

…the intruder, a Northern Harrier, soon took the hint and continued on its way.

While among the oaks, it pays to check the understory where Neotropical thrushes including the Veery are arriving to fill the forests with their melodious songs.

Following their nocturnal flights, the last of the season’s northbound White-throated Sparrows may presently be found spending the day in the cover of the oak woodland understory.

The movements of our migratory birds typically continue through much of the month of May. And peak numbers of Neotropical species often occur sometime during the second week of the month. But with habitat at the ready, favorable flight conditions could facilitate quick arrival and/or passage of the bulk of the remaining migrants during the coming week. You may want to venture out sooner rather than later—but watch your step!

The Mayapple, a native wildflower also known as the Mandrake, is now in bloom among the oak leaf litter.

And the Canada Mayflower (Maianthemum canadense), a native species also known as Wild Lily-of-the-valley, is blooming in moist mixed-oak forests.

At the edge of an oak-maple woodland, we found this lingering White-crowned Sparrow foraging among the leaf litter and fresh, shiny foliage of Poison Ivy. Songbirds can spend their days scratching the ground among these leaves of three. If you do it, you’ll be scratching something else, and you may need an ocean of calamine lotion to boot!

April 5, 2025April 5, 2025

Photo of the Day

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.

October 12, 2024

Things to See While You’re Leaf Peeping

During your foray to view the colorful foliage of the autumn landscape, a little effort will reveal much more than meets the eye of the casual observer.

Fallen Foliage in the Forest — Don’t just stand there like a bump on a log, go for a stroll, watch your step, and have a look around. There’s a lot to see out there!

The dense understory of this forest on Blue Mountain consists almost exclusively of Witch-hazel (Hamamelis virginiana).

Witch-hazel in Flower — Witch-hazel is unique among our native flowering shrubs; it blooms in autumn.

Until we experience a heavy frost, some of our most beautiful butterflies, including this Common Buckeye, remain active along forest edges.

Another native sparrow, the familiar Dark-eyed Junco, is now arriving.

Yellow-bellied Sapsuckers — The Yellow-bellied Sapsucker is a secretive migratory woodpecker that is currently moving through the region on its way to southern pine forests for the winter. Juveniles like this one in the lower right remain close to their parents during migration and continue to beg for food.

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.

Hawk Watching on Blue Mountain at Boyd Big Tree Preserve. — Mix your leaf watching with hawk watching by visiting a ridgetop vista like this one at Boyd Big Tree Preserve Conservation Area on Blue Mountain north of Harrisburg and you can double your pleasure.

In addition to spectacular foliage, you stand a good chance of seeing an inquisitive Common Raven…

Screaming Red-tailed Hawk — …or a migrating Red-tailed Hawk that gives you a good scream as it passes by…

You may even double your fun by seeing two Common Ravens…

…or a couple of migrating Red-tailed Hawks…

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.

October 5, 2024October 6, 2024

A Sunny Day to Get Things Moving Again

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.

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.

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.

September 30, 2024September 30, 2024

Delayed by a Week of Rain

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.

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.

September 12, 2024September 13, 2024

A Rare Find Among the Migrants at Second Mountain Hawk Watch

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…

A Great Crested Flycatcher. — …Great Crested Flycatcher,…

Juvenile Northern Paula — …juvenile Northern Paula,…

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.

"Kettling" Broad-winged Hawks — A “kettle” of Broad-winged Hawks climbing on a thermal updraft above Second Mountain Hawk Watch.

Light-morph and dark-morph Broad-winged Hawks — 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.

Dark-morph Broad-winged Hawk — 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!

September 11, 2024September 14, 2024

Pot o’ Gold on the Ridgetops

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

Blackpoll and Black-throated Green Warblers — As the composition of the nightly flights begins to transition to species that start their migration later in the season, numbers of birds like the Blackpoll Warbler (top) are beginning to rival those of the heretofore very common Black-throated Green Warbler (bottom).

The Bay-breasted Warbler, another common species found among the fallout flock.

A Nashville Warbler among tangles of Mile-a-minute Weed.

Adult Male Black-throated Blue Warbler — An adult male Black-throated Blue Warbler.

Blackburnian Warblers continue their southerly trek.

A Chestnut-sided Warbler feeding on Mile-a-minute Weed berries.

Adult Male Cape May Warbler — A handsome adult male Cape May Warbler.

Swainson's Thrush — A Swainson’s Thrush.

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.

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)

September 5, 2024September 30, 2024

This Week’s Review of the Morning Fallouts

Clear, cool nights have provided ideal flight conditions for nocturnal Neotropical migrants and other southbound birds throughout the week. Fix yourself a drink and a little snack, then sit down and enjoy this set of photographs that includes just some of the species we found during sunrise feeding frenzies atop several of the Lower Susquehanna River Watershed’s ridges. Hurry up, because here they come…

Cape May Warblers have an affinity for conifers like this Eastern White Pine.

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.

Scarlet Tanagers are currently a common find following nocturnal flights.

The Red-headed Woodpecker is another diurnal migrant. This denizen of temperate climates is currently beginning to move to its wintering grounds, an area that extends from the latitudes of the lower Susquehanna south to the Gulf of Mexico and central Texas.

Juvenile Red-headed Woodpecker — A juvenile Red-headed Woodpecker during a brief pit stop.

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 migration is by no means over; it has only just begun. So plan to visit a local hawkwatch or other suitable ridgetop in coming weeks. Arrive early (between 7 and 8 AM) to catch a glimpse of a nocturnal migrant fallout, then stay through the day to see the hundreds, maybe even thousands, of Broad-winged Hawks and other diurnal raptors that will pass by. It’s an experience you won’t forget.

Broad-winged Hawk Gliding Away to the Southwest — A Broad-winged Hawk gliding away to the southwest.

Be certain to click the “Birds” tab at the top of this page for a photo guide to the species you’re likely to see passing south through the lower Susquehanna valley in coming months. And don’t forget to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab to find a hawk-counting station near you.

More birds are on the way. Here’s a look at this evening’s liftoff of nocturnal migrants detected by National Weather Service Radar in State College, Pennsylvania. (NOAA/National Weather Service Doppler Radar image)

August 26, 2024September 13, 2024

Southbound Flights: On Their Way Both Night and Day

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.

Caspian Terns and Osprey — 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.

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.

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.

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!

Nocturnal Migrants at Liftoff — 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)

May 24, 2024May 25, 2024

Arboreal Birds and Tent Caterpillars

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.

Eastern Tent Caterpillar Nest — 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.

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 Kentucky Warbler (Geothlypis formosa) nests in woodland undergrowth, often near steep, forested slopes.

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.

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.

Black Cherry defoliated by Eastern Tent Caterpillars. — 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.

Black Cherry in Flower — 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.

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.

May 11, 2024May 12, 2024

More Migrating Birds

As waves of wet weather persistently roll through the Lower Susquehanna River Watershed, the tide of northbound migrants continues. Here are few of today’s highlights…

Lincoln's Sparrow — The seldom seen Lincoln’s Sparrow likes wet thickets for layovers during its passage through the lower Susquehanna valley. They are often the last of the migratory sparrows to transit the area in May. These elusive birds nest primarily in boggy thickets far to the north of our region, mostly in Canada.

As May churns on, more and more shorebirds will be moving through on their way to nesting grounds in the interior of Canada. This flock of Least and Solitary Sandpipers was found on the muddy margins of a man-made pond. Flooded portions of farm fields and stormwater basins are also good places to see these migrants as they trek north.

May 8, 2024May 14, 2024

A Pre-dawn Thunderstorm and a Fallout of Migrating Birds

In recent days, the peak northbound push of migratory birds that includes the majority of our colorful Neotropical species has been slowed to a trickle by the presence of rain, fog, and low overcast throughout the Mid-Atlantic States. Following sunset last evening, the nocturnal flight resumed—only to be grounded this morning during the pre-dawn hours by the west-to-east passage of a fast-moving line of strong thundershowers. The NOAA/National Weather Service images that follow show the thunderstorms as well as returns created by thousands of migrating birds as they pass through the Doppler Radar coverage areas that surround the lower Susquehanna valley.

Sterling, Virginia, Doppler Radar west of Washington, D.C., at 4:00 A.M. E.D.T. indicates a dense flight of northbound migrating birds located just to the south of the approaching line of rain and thunderstorms over the State College, Pennsylvania, radar coverage area. (NOAA/National Weather Service image)

More northbound birds are indicated at 4 A.M. by the radar station located at Dover, Delaware… (NOAA/National Weather Service image)

…and by the Mount Holly, New Jersey, radar site. (NOAA/National Weather Service image)

Many of the migrating birds shown here over the Binghamton, New York, radar station at 4 A.M. probably overflew the lower Susquehanna region earlier in the night. (NOAA/National Weather Service image)

And these birds over Albany, New York’s, radar station at 4 A.M. are mostly migrants that passed north over New Jersey and easternmost Pennsylvania last evening and during the wee hours of this morning. (NOAA/National Weather Service image)

Just after 4 A.M., flashes of lightning in rapid succession repeatedly illuminated the sky over susquehannawildlife.net headquarters. Despite the rumbles of thunder and the din of noises typical for our urban setting, the call notes of nocturnal migrants could be heard as these birds descended in search of a suitable place to make landfall and seek shelter from the storm. At least one Wood Thrush and a Swainson’s Thrush (Catharus ustulatus) were in the mix of species passing overhead. A short time later at daybreak, a Great Crested Flycatcher was heard calling from a stand of nearby trees and a White-crowned Sparrow was seen in the garden searching for food. None of these aforementioned birds is regular here at our little oasis, so it appears that a significant and abrupt fallout has occurred.

Looks like a good day to take the camera for a walk. Away we go!

Many early-arriving Baltimore Orioles have already begun building nests. But widespread territorial fighting today may be an indication that some latecomer orioles became trespassers after dropping in on existing territories during the morning fallout.

There’s obviously more spring migration to come, so do make an effort to visit an array of habitats during the coming weeks to see and hear the wide variety of birds, including the spectacular Neotropical species, that visit the Lower Susquehanna River Watershed each May. You won’t regret it!

Wood Ducks arrived in February and March to breed in the lower Susquehanna valley. Soon after hatching in April or May, the young leave the nest cavity to travel under the watchful gaze of their ever-vigilant mother as they search for food along our local waterways. If you’re fortunate, you might catch a glimpse of a brood and hen while you’re out looking at the more than one hundred species of birds that occur in our region during the first half of May. Good luck!

October 2, 2023October 2, 2023

Photo of the Day

A warbler found moving through trees and shrubs or foraging on the ground while bobbing its tail is likely to be a Palm Warbler. During migration, these animated passerines favor the vegetated shorelines of lakes, rivers, streams, and ponds. This affinity for water is reflected in the Palm Warbler’s choice of breeding habitat. Nesting territories are primarily located within spruce bogs east of the Rockies in Canada, Minnesota, Maine, and on the Upper Peninsula of Michigan. The bird seen here with extensive yellow underparts is known as a Yellow or Eastern Palm Warbler (*Setophaga palmarum hypochrysea*), a subspecies that nests in eastern portions of the breeding range. The duller, grayer Brown or Western Palm Warbler (*S. p. palmarum*) nests in western sections of the summer range. In the Lower Susquehanna River Watershed, both subspecies can be seen during fall migration, which peaks in late September and October as movements of the less hardy Neotropical warblers are winding down. Both subspecies spend the winter on Caribbean islands or in coastal plain areas of eastern North America. Some of the western birds pass the colder months along the Pacific coast.

September 6, 2023September 7, 2023

Surf’s Up: The Waves Keep Rolling In

“Waves” of warblers and other Neotropical songbirds continue to roll along the ridgetops of southern Pennsylvania. The majority of these migrants are headed to wintering habitat in the tropics after departing breeding grounds in the forests of southern Canada. At Second Mountain Hawk Watch, today’s early morning flight kicked off at sunrise, then slowed considerably by 8:30 A.M. E.D.T. Once again, in excess of 400 warblers were found moving through the trees and working their way southwest along the spine of the ridge. Each of the 12 species seen yesterday were observed today as well. In addition, there was a Northern Parula and a Canada Warbler. Today’s flight was dominated by Bay-breasted, Blackburnian, Black-throated Green, and Tennessee Warblers.

A Blackburnian Warbler at sunrise on Second Mountain.

A hungry Blackburnian Warbler feeding on insects.

Black-throated Green Warbler on Second Mountain. — Black-throated Green Warblers were a plentiful species among both yesterday’s and today’s waves of Neotropical migrants.

A juvenile Black-throated Green Warbler on Second Mountain — A juvenile Black-throated Green Warbler.

Tennessee Warbler on Second Mountain. — One of the scores of Tennessee Warblers seen on Second Mountain early this morning.

A male Black-throated Blue Warbler on Second Mountain. — A male Black-throated Blue Warbler.

Magnolia Warbler on Second Mountain. — Compared to yesterday’s flight, lesser numbers of Magnolia Warblers were seen today.

An adult male Wilson's Warbler on Second Mounatin. — An adult male Wilson’s Warbler was a good find among the hundreds of birds swarming the ridgetop.

Other interesting Neotropical migrants joined the “waves” of warblers…

A minimum of six Rose-breasted Grosbeaks were identified including the juvenile male seen here in first-fall plumage. Other good sightings were Scarlet Tanagers, an adult male Baltimore Oriole, and a dozen or more Ruby-throated Hummingbirds.

Least Flycatcher on second Mountain. — Three Least Flycatchers were heard calling and seen chasing one another through a stand of dead timber on the south slope below the lookout.

September 5, 2023September 17, 2023

Catch a Wave While You’re Sittin’ on Top of the World

During the recent couple of mornings, a tide of Neotropical migrants has been rolling along the crests of the Appalachian ridges and Piedmont highlands of southern Pennsylvania. In the first hours of daylight, “waves” of warblers, vireos, flycatchers, tanagers, and other birds are being observed flitting among the sun-drenched foliage as they feed in trees along the edges of ridgetop clearings. Big fallouts have been reported along Kittattiny Ridge/Blue Mountain at Hawk Mountain Sanctuary and at Waggoner’s Gap Hawk Watch. Birds are also being seen in the Furnace Hills of the Piedmont.

Here are some of the 300 to 400 warblers (a very conservative estimate) seen in a “wave” found working its way southwest through the forest clearing at the Second Mountain Hawk Watch in Lebanon County this morning. The feeding frenzy endured for two hours between 7 and 9 A.M. E.D.T.

Tennessee Warblers at Second Mountain Hawk Watch. — Tennessee Warblers (Leiothlypis peregrina) were very common among the migrants seen this morning on Second Mountain.

Tennessee Warbler at Second Mountain Hawk Watch. — An adult male Tennessee Warbler.

Nashville Warbler at Second Mountain Hawk Watch. — A Nashville Warbler.

Chestnut-sided Warbler at Second Mountain Hawk Watch. — A Chestnut-sided Warbler.

Cape May Warbler at Second Mountain Hawk Watch. — Cape May Warblers were another common species during the morning flight.

Magnolia Warbler at Second Mountain Hawk Watch. — Magnolia Warblers were frequently observed as well.

Black-and-white Warbler at Second Mountain Hawk Watch. — A Black-and-white Warbler exhibiting its nuthatch-like feeding behavior.

Blackburnian Warbler at Second Mountain Hawk Watch. — A Blackburnian Warbler.

Black-throated Green Warbler at Second Mountain Hawk Watch. — Black-throated Green Warblers were numerous.

Bay-breasted Warbler at Second Mountain Hawk Watch. — A Bay-breasted Warbler.

Wilson's Warbler at Second Mountain Hawk Watch. — This was the only Wilson’s Warbler discerned among the hundreds of warblers seen in a “wave” on Second Mountain this morning.

Not photographed but observed in the mix of species were several Black-throated Blue Warblers and American Redstarts.

In addition to the warblers, other Neotropical migrants were on the move including two Common Nighthawks, a Broad-winged Hawk, a Least Flycatcher (Empidonax minimus), and…

Scarlet Tanager at Second Mountain Hawk Watch. — At least half a dozen Scarlet Tanagers were in the treetops.

Ruby-throated Hummingbird at Second Mountain Hawk Watch. — And no less than 23 Ruby-throated Hummingbirds were counted cruising southbound past the lookout at Second Mountain Hawk Watch today.

Then, there was a taste of things to come…

Red-breasted Nuthatch at Second Mountain Hawk Watch. — One of 3 Red-breasted Nuthatches filling the air on the mountaintop with calls reminiscent of a toy tin horn. Will this summer’s forest fires in Canada prompt a significant invasion of this and other birds including winter finches in coming months? Time will tell.

Seeing a “wave” flight is a matter of being in the right place at the right time. Visiting known locations for observing warbler fallouts such as hawk watches, ridgetop clearings, and peninsular shorelines can improve your chances of witnessing one of these memorable spectacles by overcoming the first variable. To overcome the second, be sure to visit early and often. See you on the lookout!

September 1, 2023September 3, 2023

It’s Raptor and Warbler Migration Time

As we enter September, autumn bird migration is well underway. Neotropical species including warblers, vireos, flycatchers, and nighthawks are already headed south. Meanwhile, the raptor migration is ramping up and hawk watch sites throughout the Mid-Atlantic States are now staffed and counting birds. In addition to the expected migrants, there have already been sightings of some unusual post-breeding wanderers. Yesterday, a Wood Stork (Mycteria americana) was seen passing Hawk Mountain Sanctuary and a Swallow-tailed Kite (Elanoides forficatus) that spent much of August in Juniata County was seen from Waggoner’s Gap Hawk Watch while it was hunting in a Perry County field six miles to the north of the lookout! Both of these rarities are vagrants from down Florida way.

A Peregrine Falcon speeds past the lookout at Second Mountain Hawk Watch. — A Peregrine Falcon speeds past the lookout at Second Mountain Hawk Watch yesterday.

To plan a visit to a hawk watch near you, click on the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page to find a list and brief description of suggested sites throughout the Mid-Atlantic region. “Hawkwatcher’s Helper” also includes an extensive photo guide for identifying the raptors you’re likely to see.

And to identify those confusing fall warblers and other migrants, click the “Birds” tab at the top of this page and check out the photo guide contained therein. It includes nearly all of the species you’re likely to see in the lower Susquehanna valley.

May 8, 2023

What’s Flying Right Now

Here’s a quick look at just a few of the birds that have been moving northward in recent days…

May 4, 2023May 5, 2023

Stalled Migration About to Resume

For nearly a week now, a slow-moving low pressure system has not only brought heavy rain and cold temperatures to the northeastern United States, it has also stalled the northbound flights of migrating Neotropical birds. As this weather system at last drifts offshore, birds including warblers, thrushes, vireos, flycatchers, catbirds, hummingbirds, orioles, tanagers, and others should again resume their northward movements.

National Weather Service radar presently displays returns of these airborne nocturnal migrants in clear storm-free skies throughout the eastern half of the United States and Canada. As the showers and clouds depart the lower Susquehanna valley and areas to the north, the birds immediately to our south will begin to fill the void.

Gray and green halos surrounding radar stations indicate nocturnal bird migration across much of the eastern United States and Canada. Note their absence north of Maryland where the effects of the low pressure system currently located over New England are temporarily blocking these flights. (NOAA/National Weather Service radar image)

Our advice to you…plan to spend some time outdoors this weekend looking for our colorful Neotropical visitors. Their springtime songs should fill the warm air of forest and thicket. You won’t want to miss it.

April 23, 2023

Photo of the Day

April 19, 2023

Photo of the Day

Female Red-winged Blackbirds in a cattail wetland. — This year’s unseasonably mild weather has hastened the northward migration of many birds. Neotropical species including warblers and Broad-winged Hawks are already pushing through the lower Susquehanna region in numbers. But it seems the spring movement may be a little bit protracted for female Red-winged Blackbirds, which are still rolling through by the hundreds despite the males being here, some of them defending nesting territories, since late February. No sense of urgency?

March 3, 2023August 14, 2023

Plantings for Wet Lowlands

This linear grove of mature trees, many of them nearly one hundred years old, is a planting of native White Oaks (Quercus alba) and Swamp White Oaks (Quercus bicolor).

Imagine the benefit of trees like this along that section of stream you’re mowing or grazing right now. The Swamp White Oak in particular thrives in wet soils and is available now for just a couple of bucks per tree from several of the lower Susquehanna’s County Conservation District Tree Sales. These and other trees and shrubs planted along creeks and rivers to create a riparian buffer help reduce sediment and nutrient pollution. In addition, these vegetated borders protect against soil erosion, they provide shade to otherwise sun-scorched waters, and they provide essential wildlife habitat. What’s not to love?

The following native species make great companions for Swamp White Oaks in a lowland setting and are available at bargain prices from one or more of the County Conservation District Tree Sales now underway…

The Red Maple is an ideal tree for a stream buffer project. They do so well that you should limit them to 10% or less of the plants in your project so that they don’t overwhelm slower-growing species.

The River Birch (Betula nigra) is a multi-trunked tree of lowlands. Large specimens with arching trunks help shade waterways and provide a source of falling insects for surface-feeding fish. Its peeling bark is a distinctive feature.

The Common Winterberry with its showy red winter-time fruit is a slow-growing shrub of wet soils. Only female specimens of this deciduous holly produce berries, so you need to plant a bunch to make sure you have both genders for successful pollination.

American Robins feeding on Common Winterberry. — An American Robin feeding on Common Winterberry.

Common Spicebush is a shrub of moist lowland soils. It is the host plant for the Spicebush Swallowtail butterfly and produces small red berries for birds and other wildlife. Plant it widely among taller trees to provide native vegetation in the understory of your forest.

Common Spicebush foliage and berries. — Common Spicebush foliage and berries in the shade beneath a canopy of tall trees.

The Buttonbush is a shrub of wet soils. It produces a round flower cluster, followed by this globular seed cluster.

And don’t forget the Eastern Sycamore, the giant of the lowlands. At maturity, the white-and-tan-colored bark on massive specimens makes them a spectacular sight along stream courses and river shores. Birds ranging from owls, eagles, and herons to smaller species including the Yellow-throated Warbler rely upon them for nesting sites.

Yellow-crowned Night Herons Nesting in an Eastern Sycamore — Yellow-crowned Night Herons, an endangered species in Pennsylvania, nesting in an Eastern Sycamore.

So don’t mow, do something positive and plant a buffer!

Act now to order your plants because deadlines are approaching fast. For links to the County Conservation District Tree Sales in the Lower Susquehanna River Watershed, see our February 18th post.

November 11, 2022November 11, 2022

Photo of the Day

September 15, 2022September 15, 2022

Something in the Air Tonight

There’s something in the air tonight—and it’s more than just a cool comfortable breeze.

It’s a major nocturnal movement of southbound Neotropical birds. At daybreak, expect a fallout of migrants, particularly songbirds, in forests and thickets throughout the region. Warblers, vireos, flycatchers, thrushes, Scarlet Tanagers, and Rose-breasted Grosbeaks pass through in mid-September each year, so be on the lookout!

May 14, 2022

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: Common Yellowthroat — The Common Yellowthroat is one of our most frequently encountered warblers. It can be found in almost any shrubby habitat, but is particularly numerous in streamside and wetland thickets. Many remain through the summer to nest and raise young.