You may find this hard to believe, but during the colder months in the lower Susquehanna valley, gulls aren’t as numerous as they used to be. In the years since their heyday in the late twentieth century, many of these birds have chosen to congregate in other areas of the Mid-Atlantic region where the foods they crave are more readily available.
As you may have guessed, the population boom of the 1980s and 1990s was largely predicated on human activities. These four factors were particularly beneficial for wintering gulls…
Disposal of food-bearing waste in open landfills
High-intensity agriculture with disc plowing
Gizzard Shad population boom in nutrient-impaired river/Hydroelectric power generation
Fumbled Fast Food
Earthworms lifted to the soil’s surface by plowing attracted Ring-billed Gulls by the thousands to Susquehanna Valley farmlands during the late twentieth century. (Vintage 35 mm image)Filter-feeding Gizzard Shad populations thrive in nutrient-rich waters like the Susquehanna. Their rambunctious feeding style stirs up benthic sediment deposits to release more nutrients into the water column and promote the algal blooms that often lead to detrimental eutrophic conditions. Decades ago, hundreds and sometimes thousands of gulls gathered below the river’s hydroelectric dams to feed on the seemingly endless supply of small Gizzard Shad disoriented by their passage through the turbines during electric generation. (Vintage 35 mm image)
So what happened? Why are wintering gulls going elsewhere and no longer concentrating on the Susquehanna? Well, let’s look at what has changed with our four man-made factors…
A larger percentage of the lower Susquehanna basin’s household and food industry waste is now incinerated/Landfills practice “cover as you go” waste burial.
Implementation of “no-till” farming has practically eliminated availability of earthworms and other sub-surface foods for gulls.
The population explosion of invasive Asiatic Clams has reduced the Gizzard Shad’s relative abundance and biomass among filter feeders.
Hold on tight! Fast food has become too expensive to waste.
The non-native population of Asiatic Clams in the Susquehanna and most of its larger tributaries exploded during the last two decades of the twentieth century. Its present-day biomass in the river is exceeded by no other macroinvertebrate species. The share of plankton and other tiny foods that the Asiatic Clam harvests from the water column is no longer available to native filter-feeders including Gizzard Shad. Hence, Gizzard Shad biomass has been reduced and far fewer are available to attract amazingly enormous flocks of hungry gulls to hydroelectric dams. (Vintage 35 mm image)
GULLS THIS WINTER
Despite larid abundance on the lower Susquehanna not being the spectacle it was during the man-made boom days, an observer can still find a variety of medium and large-sized gulls wintering in the region. We ventured out to catch a glimpse of some of the species being seen both within the watershed and very nearby.
By far, most of the gulls you’ll encounter in the Lower Susquehanna River Watershed right now are Ring-billed Gulls. Some of them still drop by at the business end of the drive-thru lane looking for a lost order of fries and maybe a cheeseburger in paradise.First-winter (left), second-winter (center), and adult Ring-billed Gulls on the Susquehanna.Nearly every flock of gulls found in our area right now is composed exclusively of Ring-billed Gulls. The trick to finding other species, particularly rarities, is to look for slightly larger birds mixed among them, particularly American Herring Gulls like the first-winter (back row left) and third-winter (back row right) birds seen here. Herring and other species of similar-sized gulls seem to prefer each other’s company while on the wintering grounds.Five American Herring Gulls with smaller Ring-billed Gulls. The bird to the upper left and the bird hunkered down to its right are adult American Herring Gulls, the three brownish birds are in their first winter.Non-adult American Herring Gulls in flight. Always look for birds with all-pale wing tips when encountering herring gulls in flight.Midway in size between the Ring-billed Gulls in the foreground and the first-winter American Herring Gulls in the upper left and middle right of this image is a Lesser Black-backed Gull (dark-mantled bird resting at center). The similar-sized bird in the water behind it is a first-winter Iceland Gull (Larus glaucoides), a rare visitor from the arctic.Another look at the first-winter Iceland Gull from the previous image. Did you notice the all-white primary feathers and compare them to the dark wing tips on the Ring-billed Gulls seen here in its company?The conspicuously pale wings of the first-winter Iceland Gull, seen here bathing in the presence of two first-winter American Herring Gulls.Both this first-winter Iceland Gull and the bird from the previous three images are currently being seen just east of the Susquehanna watershed at Blue Marsh Lake in Berks County, Pennsylvania. Additional Iceland Gulls are currently being reported in Maryland on the Susquehanna at Conowingo Dam; on upper Chesapeake Bay in Baltimore County, Maryland; and in southeastern-most Bucks County, near Tullytown, Pennsylvania, at a busy landfill site that attracts tens of thousands of gulls each winter. Double-digit numbers of Iceland Gulls have been reported at this latter site during recent weeks.Lesser Black-backed Gulls like this one observed at Blue Marsh Lake are uncommon in the Lower Susquehanna River Watershed. They are progressively more likely as you travel east toward the aforementioned Bucks County landfills where hundreds of these birds make up a core Atlantic seaboard population.Great Black-backed Gulls are the most frequently encountered large gull on the Susquehanna. They’re easily identified by their enormous size and, as adults, their dark mantle.Rivaling the Great Black-backed Gull in size is the Glaucous Gull (Larus hyperboreus), another rare arctic visitor with pale wing tips. There are numerous reports of these unusual winter visitors from sites on Delaware Bay north to the Tullytown landfills on Delaware River where half a dozen or more have been occurring. Seen near the mouth of the Susquehanna on Chesapeake Bay at North East, Maryland, has been a first-winter bird similar to this one that we photographed at Blue Marsh Lake in Berks County, Pennsylvania.
For us, seeing a Glaucous Gull brought back memories of the last time we saw the species. It was forty-five years ago on New Year’s Day 1981 that we discovered two first-winter birds feeding on Gizzard Shad in open water on an otherwise ice-choked Susquehanna below the York Haven Dam powerhouse at Conewago Falls. Hey Doc Robert, do you remember that day?
As part of an update to our “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” page, we’ve just added this chart for determining the age of the Bald Eagles you might observe on the lower Susquehanna River and elsewhere in coming weeks.
Bald Eagle age classes as they typically appear during late autumn in the Lower Susquehanna River Watershed. (Click the image for a full-size PDF version of the chart)
Bald Eagles in each age class often retain their fall appearance through much of the winter. However, beginning January 1st, each bird is reclassified into the next in the series of chronological plumage designations. Consequently, during the early part of the new year until a new generation of eagles is hatched in late winter and spring, there are no birds in our area designated “hatch-year/juvenile”. After fledging, these youngest eagles, the new generation of juveniles, often show little change in appearance until after their first birthday, by which time they are already classified as second-year/Basic I immature birds. For birds other than the new generation of hatch-year/juvenile eagles, the majority of the molt that produces their new autumnal appearance each year occurs during spring and especially summer, when food is abundant and the bird’s energy needs for purposes other than growing feathers are at a minimum. Hence, by the time fall migration rolls around, the next in the successive progression of plumage changes is evident. For more details and year-round images of Bald Eagles, check out our “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” page by clicking the tab at the top of this page.
Wintering Bald Eagles are again congregating on the lower Susquehanna River, particularly in the area of Conowingo Dam near Rising Sun, Maryland. To catch a glimpse of the action earlier this week, we took a drive on U.S. Route 1 atop Conowingo’s impounding structure to reach Fisherman’s Park on the river’s west shore below the powerhouse.
Scores of dedicated eagle watchers and photographers brave the raw weather to see and document the concentration of eagles that gather to feed and roost in the vicinity of Exelon Energy’s Fisherman’s Park.The panoramic view of the Susquehanna from Fisherman’s Park offers excellent opportunities to witness Bald Eagle activity.When you arrive, it’s not unusual to hear the sounds of squabbling eagles immediately upon exiting the shelter of your vehicle. During our visit, we sighted probably 60 to 80 individuals of various age classes among the rocks and trees along the river shorelines below the dam.Soon enough, we experienced a close fly-by from this second-year Bald Eagle.Another of the many second-year Bald Eagles seen on the Susquehanna at Conowingo Dam.We were a little bit concerned to see only one hatch-year (juvenile) Bald Eagle among the birds at Fisherman’s Park. Perhaps the aggressive behavior of the large number of older and more experienced eagles in the area has these first-year individuals shying away. We discerned no third-year birds either, though they may certainly have been present.A probable fourth-year Bald Eagle shows a white head with the remains of a dark line through the eye, a trait often more conspicuous in third-year birds often known as “osprey face” eagles.This probable fifth-year Bald Eagle has nearly lost the dark markings on the head and tail that differentiate immature birds from adults. A molt during the coming year will yield adult plumage and mark the completion of this bird’s sexual maturity.An adult Bald Eagle.Meanwhile, a little action gets the shutters clicking,……a fourth-year Bald Eagle (top) is drawing the ire of an adult bird,……necessitating a reprisal for the taunting behavior.
To the delight of photographers at Conowingo, some of the eagles can be seen grabbing fish, mostly Gizzard Shad, from the tailrace area of the river below the powerhouse. But Bald Eagles are opportunistic feeders, and their feeding habits are similar to those of numerous other birds found in the vicinity of the dam at this time of year—they’re scavengers. Here’s a glimpse of some of the other scavengers found in the midst of this Bald Eagle realm…
Fish Crows are recognized by their nasal call. They’ll eat almost anything they can find including garbage, fish remains, discarded bait, lunch scraps, road kill, and more.Visitors to Fisherman’s Park are warned to keep out of sight any food they may have stored in their cars. Black Vultures are known to peel rubber away from windows as they search for something to eat, a habit they possibly learned during productive forays to landfills where the edges of rubber coverings sometimes hide a freshly dumped buffet of potential sustenance.During our stop at Conowingo Dam earlier this week, we saw only one Turkey Vulture, though more are certainly in the vicinity feeding on road kill and other carrion.Like eagles, Ring-billed Gulls are opportunistic feeders, seen here looking for disoriented Gizzard Shad and other fish,……then quickly changing focus to check the humans along the shoreline for discarded bait or fumbled snack foods.Even young Ring-billed Gulls learn the value of watching people for activities that provide an opportunity to scavenge food.While Ring-billed Gulls and other scavengers aren’t particularly fussy about what they eat, Double-crested Cormorants are;……they’re targeting Gizzard Shad and other fish in the waters below the dam. Thus, we would categorize cormorants as predators, eating mollusks and other aquatic organisms as well.And while you’re on the lower Susquehanna, keep an eye on the sky. Common Mergansers winter on ice-free sections of the waterway and are now arriving in the vicinity of Conowingo and elsewhere.But if perhaps winter isn’t your thing, don’t despair. These Bald Eagles came upon last year’s Great Blue Heron rookery on the island below the dam and it seems to be giving them some ideas. If you think like an eagle, spring is just weeks away!
Here are a few more late-season migrants you might currently see passing through the lower Susquehanna valley. Where adequate food and cover are available, some may remain into part or all of the winter…
During the summer, Ruby-crowned Kinglets nest in northern coniferous forests. Through the colder months, these petite songbirds can often subsist on tiny insects and other invertebrates found among the bark, limbs, and buds of leafless deciduous trees and shrubs. In our region, look for wintering kinglets in woodlands that include at least a small percentage of evergreens to provide protection from frigid nighttime temperatures.The Yellow-bellied Sapsucker is our shiest of woodpeckers. These migrants are still quite common among stands of deciduous and mixed woods, but local numbers will soon decrease as the majority of the population continues moving along to the forests of the southeastern United States for winter.Migrating American Robins are still transiting region, but an abundance of wild fruits can prompt hundreds to linger through winter. Look for them near supplies of wild grape, Poison Ivy, dogwood, Virginia Creeper, hackberry, hawthorn, American Holly,……Eastern Red Cedar,……and Common Winterberry.In case you were wondering…Yes, the adult Red-shouldered Hawk continues to visit the garden pond at susquehannawildlife.net headquarters. Earlier today, we watched it plunge into the shallows after a Green Frog. We’re enjoying the privilege of having it around, so we hope it decides to remain for as long as the food supply is accessible.
Peak numbers of Fox Sparrows are now moving through the lower Susquehanna valley on their way south. Nearly as large as our Catharus thrushes, these native songbirds are among the last of our regularly occurring autumn migrants. In tangled dense thickets along the edges of fields and woodlots, small numbers may linger into winter eating berries and the seeds of herbaceous plants.
Back for an afternoon visit on a limb above the pond, our surprise guest seems to find our dining experience irresistible. During recent winters, the Green Frogs in the headquarters habitat have continued to be active through at least New Year’s Day. If it appears we’re going to have a Red-shouldered Hawk lingering that long, perhaps we’ll be motivated to clean our windows so we might get an even better look.
Earlier this morning, we photographed this adult Red-shouldered Hawk as it took a break from its southbound journey to eye up the Green Frogs in the susquehannawildlife.net headquarters pond. Hunger must surely outweigh timidity because this bird persisted in its hunt despite the activity of a crew of contractors noisily grinding up asphalt in the street just 40 feet away!
Those cold, blustery days of November can be a real downer. But there’s a silver lining to those ominous clouds, and it comes with the waves of black and mostly dark-colored migrants that stream down the ridges of the Lower Susquehanna River Watershed on their way south at this time of year.
For protection from predators, blackbirds including these Common Grackles typically assemble into sizeable flocks numbering hundreds of birds following the nesting season. These noisy bands of passerines are currently being seen as they move south into the Piedmont and Atlantic Coastal Plain for winter.American Crows are now working their way into the area. To avoid falling prey to owls and other predators during the night, they form often enormous roosts in well-lit urban areas. They spend their days fanning out across the landscape in search of food, primarily relying upon human-generated fare including road kill and scraps found among trash and litter for sustenance.Formerly confined largely to remote mountainous terrain, the crow’s close relative the Common Raven has, during this century, become more widespread and tolerant of human activity.Ravens are frequently seen in small groups of just two to five birds. During November however, they may assemble into playful bands of ten or more birds as they roam the ridges in search of suitable places to pass the winter.Spending time at one or more of the regional hawk-counting stations during coming weeks will afford you not only the chance to see ravens, but many of our largest raptors as well. Their migration is just now reaching its peak.Peak numbers of Red-tailed Hawks are migrating through the area right now. Though their population is in decline overall, they may appear very common along rural roadways and in suburbia during coming weeks as they try to find prey before continuing south. Inexperienced juvenile “red-tails” are particularly vulnerable to fatal traffic mishaps and other hazards during this time. Give them some room if you can.Early November brings the last of the season’s Osprey down local ridges. Many, including this one seen earlier in the week, will fly right up until sunset to expedite their journey to warmer climes.Always a crowd-pleaser among the observers on the lookouts are the eagles.Flights right now consist primarily of Bald Eagles.Updrafts created as strong autumn winds strike the slopes of local ridges are providing the lift needed for these birds to cover many miles per day with minimal energy expended.Right now, migrating Bald Eagle numbers are often exceeding a dozen birds per day at local counting stations. They include those like this one in juvenile (hatch-year) plumage as well as the various molt sequences experienced by immature eagles prior to reaching maturity.But nearly everyone’s favorite is the close approach of a Bald Eagle in definitive adult plumage.At present, Golden Eagle numbers are just starting to build. Look for the peak of their fall migration to arrive in coming weeks. Gusty days following passage of a cold front are often your best bet for seeing these regal raptors from local lookouts.
For more information on regional hawkwatching sites and raptor identification, click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page. And for more on Golden Eagles specifically, click the “Golden Eagle Aging Chart” tab.
Bright moonlight tonight……will bring familiar nocturnal migrants like this Dark-eyed Junco to your garden, feeding station, or other favorite birding place by morning.
Small numbers of Rusty Blackbirds are currently moving south through the Lower Susquehanna River Watershed. Look for individuals and small flocks feeding in damp woods and along lake and river shorelines. These uncommon birds nest far to our north in wet coniferous and mixed forests as well as willow thickets, often in muskeg or beaver pond-created habitat. Rusty Blackbirds spend the colder months in the wooded swamps of the southeastern and south-central United States. Loss of habitat has reduced their numbers dramatically, as has their misfortune to occasionally join flocks of foraging Red-winged Blackbirds and Common Grackles on the wintering grounds where all of these species fall victim to avicide poisons placed on feedlots to eradicate European Starlings.
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!
These juvenile Rose-breasted Grosbeaks are among the last big southbound push of Neotropical migrants we’ll see moving through the lower Susquehanna valley in coming days. Be certain to get outside and have a look.
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.
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.Not to be outdone, this Northern Parula joined in with a cheery tune from yet another Staghorn Sumac.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 passing through the lower Susquehanna valley in fall, Broad-winged Hawks can be seen ascending to greater heights above almost any sun-drenched surface including large parking lots or barren fields. But to get your best look, visit a ridgetop hawk watch where these birds circle on the rising air created by solar heating of the south-facing slopes.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…
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.
Chilly nights and shorter days have triggered the autumn migration of Neotropical birds. You may not have to go far to see these two travelers. Each is a species you may be able to find migrating through your neighborhood.
Common Nighthawks are large insect-eating nightjars. Watch for them feeding and migrating overhead during the late hours of the afternoon and continuing through nightfall. While skies above the Susquehanna and large tracts of forest or grassland offer the best viewing opportunities, even city residents may witness their evening flights during the coming weeks. Though nighthawk numbers appear to be in decline, as many as a hundred or more are currently being seen nightly at Pine Grove Furnace State Park along South Mountain in Cumberland County, Pennsylvania. For daytime roosting during their southbound movements, nighthawks seem to be attracted to deep shade in areas of vast forest. They will often seek sanctuary and become concentrated in “islands of darkness” like Michaux State Forest on South Mountain after passing over light-polluted urban areas such as Harrisburg and the adjoining metroplex of the Great Valley during the previous night.Ruby-throated Hummingbirds are now moving south. It’s time to be extra vigilant about keeping your sugar-water dispensers clean and filled with fresh nectar mixture. For tips on feeding hummingbirds safely, check out our post from August 5, 2022, “Two Feeders Are Better Than One”.
It may seem hard to believe, but the autumn migration of shorebirds and many Neotropical songbirds is now well underway. To see the former in what we hope will be large numbers in good light, we timed a visit to the man-made freshwater impoundments at Bombay Hook National Wildlife Refuge near Smyrna, Delaware, to coincide with a high-tide during the mid-morning hours. Come along for a closer look…
Along a large portion of its route, the tour road at Bombay Hook N.W.R. sits atop the man-made dikes that create several sizeable freshwater pools (left) along the inland border of one of the largest remaining salt marsh estuaries in the Mid-Atlantic States (right).Twice daily, the rising tide from Delaware Bay flows along the tidal creeks to flood Bombay Hook’s extensive marshes.At high tide, mudflats in Bombay Hook’s coastal estuary become inundated by salt water, forcing migratory shorebirds to relocate to bay side beaches or other higher ground to rest and feed for several hours.At Bombay Hook, migratory shorebirds, waterfowl, and waders can find refuge from high tide in the freshwater impoundments created by capturing water along the inland west side of a system of earthen dikes.Mechanical or stacked-board gate systems are used to control water depth in the impoundments. Levels can be adjusted seasonally to manage plant growth and create conditions favorable for use by specific groups of birds and other wildlife.A map at Shearness Pool, the largest impoundment on the refuge, shows the location of other freshwater pools at Bombay Hook.A mix of mudflats and shallow water on Raymond Pool provides ideal habitat for a variety of shorebirds forced from the vast tidal marshes by the rising tide. For us, a mid-morning high tide places these birds in perfect light as they feed and loaf in the pools to the west of the tour road located atop the dikes.Migrating shorebirds arrive on Raymond Pool to find refuge from the rising tide to the east. Showing a single ring around their breast, many Semipalmated Plovers can be seen here among the Semipalmated Sandpipers, the latter the most abundant shorebird presently populating Bombay Hook. Feeding in deeper water in the background are Short-billed Dowitchers. All of these birds consume a variety of invertebrates they find both in and on the mud.Semipalmated Plovers and Semipalmated Sandpipers arriving on a mudflat at Raymond Pool.A Short-billed Dowitcher glides in from the salt marsh to visit the shallows of Raymond Pool for a couple of hours.A Short-billed Dowitcher feeding among Semipalmated Plovers and Semipalmated Sandpipers.Short-billed Dowitchers in water almost too deep for the Semipalmated Sandpipers in their company.A lone Black-bellied Plover (Pluvialis squatarola) among the abundance of Short-billed Dowitchers.Short-billed Dowitchers probe the mud with their sewing machine-like feeding style.Seldom do they take a break long enough for an observer to their bill in its entirety.A Lesser Yellowlegs arrives at Raymond Pool as a high-tide refugee.Another Lesser Yellowlegs on a mudflat.A Greater Yellowlegs wades into shallow water to feed.It’s difficult to estimate just how many Semipalmated Plovers and Semipalmated Sandpipers were seen. There were at least 500 plovers, and they were very vocal. The latter species was present in numbers measurable in the thousands. We don’t think 10,000 Semipalmated Sandpipers is an overestimate.Searching through the Semipalmated Sandpipers, one could regularly find a very similar species among them.We identified the longer-billed and slightly larger Western Sandpiper (Calidris mauri) and found the species to be present possibly by the hundreds among the masses of thousands of Semipalmated Sandpipers. These seem to be unusually high numbers for this more western species, but who’s complaining?As we sifted through these groups of tiny shorebirds known as “peeps”, we found Western Sandpipers (top) regularly distributed among the multitudes of Semipalmated Sandpipers (bottom) we encountered.A Western Sandpiper (top) photographed with a Semipalmated Sandpiper (bottom) in Bear Swamp Pool.Of course, shorebirds aren’t all there is to see at Bombay Hook. More than 100 Snowy Egrets were found on the freshwater pools alongside birds like this Semipalmated Plover.Great Egrets could be seen stalking small fish in the channels of the pools.And a few Green Herons were found lurking in the vegetation.This Osprey briefly startled the shorebirds on Raymond Pool until they realized it posed no threat.By early afternoon, we noticed the tide beginning to retreat from the saltwater marsh and mudflats opposite Shearness Pool. As shorebirds began returning there to feed, we decided to make our way to Raymond Pool to watch the exodus.With the high tide receding from the coastal estuary back into Delaware Bay, shorebirds promptly departed their concentrated environs on Raymond Pool to spread out over thousands of acres of salt marsh to feed.More shorebirds exit Raymond Pool en route to the adjacent tidal areas to feed. This outbound group includes two Black-bellied Plovers (top center and four birds to the right).These migrants have just begun their autumn journey from breeding grounds in Canada and Alaska to wintering areas located as far south as southern South America. For them, Bombay Hook and other refuges are irreplaceable feeding and resting locations to help them refuel for their long journey ahead. For them, a little vacation along the coast is a matter of life and death.A goodwill ambassador bids us farewell at the end of our visit to Bombay Hook. Remember to support your National Wildlife Refuges by purchasing your annual Federal Duck Stamp. They’re available right now at your local United States Post Office, at the Bombay Hook visitor’s center, or online at the United States Fish and Wildlife Service website.
Planning a visit? Here are some upcoming dates with morning high tides to coax the birds out of the tidal estuary and into good light in the freshwater impoundments on the west side of the tour road…
Tuesday, August 19 at approximately 07:00 AM EDT
Wednesday, August 20 at approximately 08:00 AM EDT
Now that the nesting season is drawing to a close, Ruby-throated Hummingbirds are a bit less fussy about where they spend their time. Even in urban settings, gardens with an abundance of nectar-producing flowers like this Scarlet Bee Balm (Monarda didyma) have a good chance of attracting them. Hummingbirds will be wandering the landscape and starting to drift south during the coming two months, so keep your feeders clean and filled with a fresh blend of sugar water to keep them energized and happy. If you’re feeding hummingbirds, or thinking about feeding hummingbirds, be sure to review the helpful tips contained in our post from August 5, 2022, “Two Feeders Are Better Than One”. Their health and your peace of mind may depend on it.
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 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.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.This male Black-and-white Warbler appears a little bit ruffled as he dries out his feathers following a brief afternoon downpour. But as the sunshine returns, he bursts into song from a forest perch within the nesting territory he has chosen to defend. In addition to the vocalizations, this eye-catching plumage pattern helps advertise his presence to both prospective mates and would-be trespassers alike. But against the peeling bark of massive trees where this bird can often be found quietly feeding in a manner reminiscent of a nuthatch, the feathers can also provide a surprisingly effective means of camouflage.
One of dozens of Cedar Waxwings seen descending upon ripe juneberries in a mini grove consisting of either Smooth Shadbush (Amelanchier laevis) or the allied and very similar-looking hybrid juneberry Amelanchier x lamarkii. Smooth Shadbush can be grown as a shrub or small tree and is also known as Smooth Serviceberry, Allegheny Serviceberry, or Smooth Juneberry. The hybrid Amelanchier x lamarkii is believed to be a naturally occurring cross between Smooth Shadbush (A. laevis) and either Canadian Serviceberry (A. canadensis) or Downy Serviceberry (A. arborea). Juneberries/serviceberries/shadbushes, including a number of man-made cultivars, produce white flowers in early spring and can be obtained through numerous suppliers for inclusion in conservation projects, home gardens, or for use as street trees. Believe it or not, the very productive planting seen here was located in a parking lot island at a busy Walmart store.
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.The buds of the Mountain Laurel remind us of a sugary frosting freshly squeezed from a baker’s pastry bag.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.Another red-spotted Purple seen picking up minerals from a dried up puddle depression on a gravel road.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.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.A Common Pawpaw understory along the approach to Schull’s Rock.A colonial stand of Common Pawpaw along the trail leading 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!And the view of the Susquehanna and the Shock’s Mills railroad bridge at the mouth of Codorus Creek is pretty good too!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.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……but pause frequently to repeat a song often described as something akin to that which might be performed by a robin subjected to voice lessons. The Rose-breasted Grosbeak is certainly a bird worth seeing and hearing.
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.
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.
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 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.The solution to their dilemma is as advertised. Instead of cutting the grass, why not take heed of the example set here and cut back on the tens of thousands of acres that are excessively or needlessly mowed in the Lower Susquehanna River Watershed? How ’bout letting a significant percentage of your property regenerate as successional habitat as well? It can and does make a difference!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.
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…
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.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.This Muskrat (Ondatra zibethicus) with a leafy twig in tow takes advantage of spring’s new growth to construct or repair its house,……a process that can be repeated or renewed as necessary throughout the year.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……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.You see, the Blue-gray Gnatcatcher relies on plenty of web-spinning spider activity to supply the construction materials it needs.A Blue-gray Gnatcatcher pulling apart a spider’s web on a warm May morning.Back at the nest site……the sticky spider webs bind together lichens and small bits of bark……to form a perfect little cup for the nesting Blue-gray Gnatcatchers.Baltimore Orioles weave one the most unique nests of any species occurring in eastern North America.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.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.All his effort is expended in an attempt to impress her and thus have a chance to mate.This male can indeed put all his energy into the courtship ritual because Brown-headed Cowbirds toil not to build a nest. They instead locate and “parasitize” the nests of a variety of other songbirds. After mating, the female will lay an egg in a host’s abode, often selecting a slightly smaller species like a Yellow Warbler or native sparrow as a suitable victim. If undetected, the egg will be incubated by the host species. Upon hatching, the larger cowbird nestling will dominate the brood, often ejecting the host’s young and/or eggs from the nest. The host parents then concentrate all their efforts to feed and fledge only the young cowbird.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.
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.Not far away, we spied this Yellow-rumped Warbler.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.A fortunate observer may catch a glimpse of one perched in an understory shrub or small tree.But hearing the Ovenbird’s song, “teacher-teacher-teacher”, is frequently the only way to detect it.The Worm-eating Warbler nests in understory thickets on steep forested slopes. Its rich chipping song is often the only indication of its presence.Frequently easier to locate is the American Redstart, a Neotropical warbler that calls out its territory in damp woodlands from perches atop shrubs or among the lower limbs of trees.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.Like the mockingbird and thrasher, the Yellow-breasted Chat is a mimic. Its song is a repertoire of the calls and songs of the bird species with which it may compete for food and nesting space. Unique to the chat is an occasional pause, whistle, or “chuck” note that creates a bridge between many of its song’s elements.The intensely territorial chat dropping down to look us over.
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.Seeing is believing.
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.
Periods of rain need not put a damper on a day outdoors observing birds that wintered in a rain forest or other tropical environment.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.Rain or shine, male Indigo Buntings were busy singing. All this exuberance is intended not only to establish and defend a nesting territory……but to attract the attention of a mate as well.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.We found three male Blue-winged Warblers singing on territories in this bushy clearing where electric transmission lines pass over Third/Stony Mountain on State Game Lands 211.Their presence at this site is testament to the importance of maintaining corridors of quality successional habitat in the landscape.The Blue-winged Warbler is a Neotropical migrant with an easy-to-learn song. It’s a very simple, buzzy sounding “beeee-bzzz”.Another Neotropical species that nests in successional thickets is the Prairie Warbler (Setophaga discolor), seen here during one of this morning’s downpours.The Prairie Warbler can sometimes be found in stands of pioneer plants like Eastern Red Cedar on sites with barren soils or those that have been subjected to wildfire.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.The presence of a Mountain Laurel thicket also enhances a forest’s ability to host breeding Hooded Warblers.
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.
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.
Brilliantly colored migrants continue to arrive from their tropical wintering grounds. Look for the Indigo Bunting in thickets and other successional habitat. They are particularly fond of seldom-manicured utility right-of-ways and railroads where males like this one can be seen singing from an exposed perch to defend a nesting territory and attract a mate.
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.Slightly larger than the warblers are the vireos, including this Yellow-throated Vireo that has arrived to nest in an oak-maple bottomland.Always a fan favorite, we found this marvelously tropical Baltimore Oriole among the foliage of a flowering White Oak.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!
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.
A Ring-necked Pheasant forages among the fresh green growth two weeks to the day after prescribed fire was administered to this parcel at Middle Creek Wildlife Management Area to turn back plant succession and maintain grassland habitat.
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.
