This Week’s Enormous Diurnal Flights

For the past several weeks, we’ve given you a look at the fallout of Neotropical songbirds on mornings following significant nocturnal flights of southbound migrants.  Now let’s examine the diurnal (daytime) flights that have developed in recent days over parts of the lower Susquehanna basin and adjacent regions.

For those observing diurnal migrants, particularly at raptor-counting stations, the third week of September is prime time for large flights of tropics-bound Broad-winged Hawks.  Winds from easterly directions during this year’s movements kept the greatest concentrations of these birds in the Ridge and Valley Province and upper areas of the Piedmont as they transited our region along a southwesterly heading.  Counts topped 1,000 birds or more on at least one day at each of these lookouts during the past seven days.  Meanwhile at hawk watches along the Piedmont/Atlantic Coastal Plain border, where flights topped 10,000 or more birds on the best days last fall, observers struggled to see 100 Broad-winged Hawks in a single day.

Broad-winged Hawks
Dozens of migrating Broad-winged Hawks during a morning liftoff to the north of Blue Mountain.

Among the challenges counters faced while enumerating migratory Broad-winged Hawks this week was the often clear blue skies, a glaring sun, and the high altitude at which these raptors fly during the mid-day hours.

"Kettling" Broad-winged Hawks
Large numbers of Broad-winged Hawks climbing on a thermal updraft to gain altitude can become increasingly difficult to spot in a clear blue sky.
"Kettling" Broad-winged Hawks
Higher and higher they go until they practically disappear from view.
Broad-winged Hawks
Cloud cover can help make locating really high-flying birds a bit easier, but they can sometimes climb into the lower portion of the cloud and vanish.

Another factor complicating the hawk counters’ tasks this week, particularly west of the Susquehanna River, was the widespread presence of another group of diurnal fliers.

Blue Jay
Was it the migratory Blue Jays that are beginning to move through the area?   No.
Sharp-shinned Hawk
Was it the increasing numbers of Sharp-shinned Hawks and other raptors?  No.
Hawkwatchers Scanning the Skies
So what was it that complicated the hawkwatchers’ efforts to find high-flying Broad-winged Hawks during this week’s flights?
Spotted Lanternfly
Is it a bird?  Is it a plane?  No.  And it’s nobody’s superhero either.  It’s the non-native Spotted Lanternfly and it is now very numerous west of the Susquehanna and common enough to the east to make even experienced observers take a second look while scanning the skies for Broad-winged Hawks and other migrating raptors.  Just how many do raptor counters have to contend with?  Even where these invasive insects have become less populous in the lower Susquehanna valley, hundreds still fill the skies above forest clearings around hawk-counting stations including Waggoner’s Gap, Second Mountain, and Rocky Ridge County Park.
Spotted Lanternflies on Radar
Spotted Lanternfly populations explode with great vigor as they colonize areas with plenty of tender new growth on native, non-native, and cultivated shrubs, trees, and vines.  Earlier this week, National Weather Service Doppler Radar in Pittsburgh, Pennsylvania, captured enormous mid-afternoon flights of Spotted Lanternflies in recently invaded areas of southwestern Pennsylvania and eastern Ohio.  (NOAA/National Weather Service Doppler Radar image)
Spotted Lanternflies on Radar
A base velocity image consisting primarily of Spotted Lanternflies in southwestern Pennsylvania and eastern Ohio.  (NOAA/National Weather Service Doppler Radar image)

As the Broad-winged Hawk migration draws to a close during the coming ten days, the occurrence of the one dozen other migratory diurnal raptors will be on the upswing.  They generally fly at lower altitudes, often relying upon wind updrafts on the ridges for lift instead of high-rising thermal updrafts.  They therefore present better observation opportunities for visitors at hawk watch lookouts and are less frequently confused with high-flying Spotted Lanternflies.

Merlin
A Merlin seen earlier this week migrating through the Lower Susquehanna River Watershed.  The numbers of migrating Merlins and other falcons will peak sometime in coming weeks.

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.

Red-eyed Vireo
One of more than half a dozen Red-eyed Vireos seen during a daybreak fallout at Second Mountain Hawkwatch in Lebanon County earlier this week.
Blackburnian Warbler
During sunrise, a just-arrived Blackburnian Warbler checks the foliage of a ridgetop Red Maple for insects.
Least Flycatcher
A Least Flycatcher quietly searches the shrubby growth along the forest edge for a morning meal.
Black-and-white Warbler
A Black-and-white Warbler in the first hour of sunlight after a big nocturnal flight.
Scarlet Tanager
A Scarlet Tanager having a look around.  This individual and other migrating birds may be here for a few days before moving on.
Black-throated Green Warbler
A Black-throated Green Warbler in a treetop glowing with the light of sunrise.
Chestnut-sided Warbler
A hungry Chestnut-sided Warbler inspects limbs, leaves, and twigs looking for nourishment after an all-night flight.

Diurnal migrants, birds that make their movements during the daylight hours, are ramping up their flights now as well.  Broad-winged Hawks, Bald Eagles, and falcons are currently being tallied at hawk-counting stations throughout the northeast.  Many of those lookouts are seeing Ruby-throated Hummingbirds, swallows, and other daytime migrants too.

Broad-winged Hawk
While many diurnal migrants gather in flocks as a method of defense against predators, Broad-winged Hawks congregate as a reconnaissance measure.  Not waiting around for strong autumn winds to be deflected upwards by the region’s numerous ridges, these Neotropical birds migrate early enough in the season to rely upon thermal updrafts from sun-heated surfaces to provide lift, gain altitude, and save energy during their long trip.  By traveling in groups, there are collectively able to better locate and utilize rising air columns as they progress southwesterly along their route.  Broad-winged Hawks travel to Central and South America for winter.  Their numbers in the Lower Susquehanna River Watershed will peak during the third week of September.
American Kestrel
Many American Kestrels transit our area in August and early September, a time coinciding with flights of migratory dragonflies, insects upon which they and another falcon, the Merlin, frequently prey.
Chimney Swifts
Chimney Swifts are fast-flying diurnal migrants.  They are beginning to congregate into larger groups in preparation for their departure.  Some are already on the move.
Cedar Waxwing
Cedar Waxwings are currently being seen in roving flocks throughout the region.  Their migration is less of a point-to-point flight and more of a continuous wandering in search of berries and other wild foods.
American Goldfinch
Not everyone is yet ready to go.  American Goldfinches are still in the midst of their nesting cycle and won’t begin leaving until the young are on their own and colorful adult males like this one are beginning to molt into their drab winter plumage.

Autumn migration flights are an ever-changing process, with different species peaking at different times throughout the season.  In these months just after the nesting season, each of these species is more numerous than at any other time of the year.  And of course, the more often we as observers get out and have a look, the more of them we’ll see.

Be certain to click the “Birds” tab at the top of this page for a photo guide to the species you’re likely to see passing through the lower Susquehanna valley this fall.  Nearly four months of autumn hawk migration flights lie ahead, so don’t forget to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab to find a hawk-counting station near you, then stop by for a visit or two.  See you there!

A large nightfall liftoff of nocturnal migrating birds is shown here on this evening’s State College, Pennsylvania, Doppler Radar base velocity loop.  Returns indicating birds moving toward the radar site (the white dot in the center of the color mass) are shown in green, and those indicating birds moving away are indicated in red.  This is a big flight headed generally in a south-southwest direction.  (NOAA/National Weather Service Doppler Radar image)

This Week at Regional Hawk Watches

With nearly all of the Neotropical migrants including Broad-winged Hawks gone for the year, observers and counters at eastern hawk watches are busy tallying numbers of the more hardy species of diurnal raptors and other birds.  The majority of species now coming through will spend the winter months in temperate and sub-tropical areas of the southern United States and Mexico.

Here is a quick look at the raptors seen this week at two regional counting stations: Kiptopeke Hawk Watch near Cape Charles, Virginia, and Second Mountain Hawk Watch at Fort Indiantown Gap, Pennsylvania.

Kiptopeke Hawk Watch
The hawk-watching platform at Kiptopeke State Park is located along Chesapeake Bay near the southern tip of Delmarva Peninsula.  In autumn, thousands of raptors and other birds migrate through the Atlantic Coastal Plain Province.  Those that follow the shorelines south frequently concentrate in spectacular numbers before crossing the mouths of the bays they encounter.  This phenomenon makes both Cape May, New Jersey, on Delaware Bay and Kiptopeke, Virginia, on Chesapeake Bay exceptional places to experience fall flights of migrating birds.
Second Mounatin Hawk Watch
A Sharp-shinned Hawk is counted as it swoops by the owl decoy at Second Mountain Hawk Watch at Fort Indiantown Gap Military Reservation.  Migrating raptors save energy by riding updrafts of air created by winds blowing against the slopes of the mountainsides in the Ridge and Valley Province.
Sharp-shinned Hawk
A Sharp-shinned Hawk passes the lookout at Second Mountain Hawk Watch.  “Sharp-shins” are currently the most numerous migrants both on the coast and at inland counting stations.
Sharp-shinned Hawk
A Sharp-shinned Hawk nearly passes observers unnoticed as it skims the treetops.
Sharp-shinned Hawk at owl decoy.
A Sharp-shinned Hawk eyes up an owl decoy.  Under cover of darkness, nocturnal owls could rather easily prey upon young and small adult hawks and falcons, both on the nest or at roost.  Accordingly, many diurnal raptors instinctively harass owls to drive them from their presence.  An owl decoy at the lookout helps attract migrating birds for a closer look.
Cooper's Hawk
An adult Cooper’s Hawk flaps its way past a counting station.  Like the similar Sharp-shinned Hawk, the larger Cooper’s Hawk is a member of the genus Accipiter.  As a proportion of the annual fall Accipiter flight, the Cooper’s Hawk is more numerous at coastal hawk watches than at inland sites.  (Editor’s Update:  As of autumn, 2024, the Cooper’s Hawk and the American Goshawk have been placed in the genus Astur.  The Sharp-shinned Hawk remains in the genus Accipiter.  Though the Cooper’s Hawk and Sharp-shinned Hawk are oft times confused by observers due to their like appearance, it turns out that the two are not as closely related as originally believed.  Neither is an offshoot of the other, nor do they descend from an immediate common ancestor.  Their resemblance may instead be a case of convergent evolution, most readily characterized by acquisition of similar physical traits due to shared demands for survival within their environment.)
Osprey
The majority of Osprey migrate along the coast, but a few are still being seen at inland hawk watches.
Bald Eagle
Bald Eagles are commonly seen at both coastal and inland lookouts.  Their movements continue well into late fall.
Northern Harrier
A Northern Harrier illuminated by a setting sun.  Northern Harriers are often still flying when many other species have gone to roost for the day.
An adult male Northern Harrier flying in misty weather.
An adult male Northern Harrier, the “gray ghost”, flying in misty weather, at a time when few other birds were in the air.
American Kestrel
The American Kestrel, like our other falcons, is seen in greatest concentrations at coastal counting stations.  It is our most numerous falcon.
Merlin
The Merlin provides only a brief observation opportunity as it passes the lookout.  These falcons are dark, speedy, and easily missed as they fly by.
Tree Swallow
While moving south, Merlins often accompany flights of migrating Tree Swallows, a potential food source.
Merlin with Dragonfly
A Merlin consumes a dragonfly.  Eating is no reason to stop moving.
Juvenile "Tundra Peregrine"
The “Tundra Peregrine” is an arctic-breeding Peregrine Falcon that travels a distance of over 6,000 miles to southern South America for winter.  It is strictly a migratory species in our region with numbers peaking during the first two weeks of October each year.  These strong fliers have little need for the updrafts from mountain ridges, inland birds often observed flying in a north to south direction.  The majority of “Tundra Peregrines” are observed following coastlines, with some migrating offshore to make landfall at points as far south as Florida and the Caribbean islands before continuing across water again to reach the northern shores of Central and South America.  This “Tundra Peregrine” is a juvenile bird on its first southbound trip.

During coming days, fewer and fewer of these birds will be counted at our local hawk watches.  Soon, the larger raptors—Red-tailed Hawks, Red-shouldered Hawks, and Golden Eagles—will be thrilling observers.  Cooler weather will bring several flights of these spectacular species.  Why not plan a visit to a lookout near you?  Click on the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page for site information and a photo guide to identification.  See you at the hawk watch!

Common Raven
It’s not all hawks at the hawk watch.  Even the coastal sites are now seeing fun birds like the playful Common Raven on a regular basis.
Eastern Meadowlarks in a Loblolly Pine.
Coastal locations are renowned places to see migrating songbirds in places outside of their typical habitat.  Here a flock of Eastern Meadowlarks has set down in the top of a Loblolly Pine (Pinus taeda) in downtown Cape Charles, Virginia, not far from Kiptopeke Hawk Watch.

Photo of the Day

Merlin
Lightning fast, a migrating Merlin quickly passes a raptor counting station’s lookout.  The falcons are on their way south right now, so be certain to click the “Hawkwatcher’s Helper” tab at the top of this page to locate a hawk watch near you.  Then pack a snack and go sit for a while to enjoy the birds and the autumn foliage.

Big Broad-winged Hawk Flights Are Underway

Flights of southbound Broad-winged Hawks have joined those of other Neotropical migrants to thrill observers with spectacular numbers.  In recent days, thousands have been seen and counted at many of the regions hawkwatching stations.  Now is the time to check it out!

A "kettle" of Broad-winged Hawks gaining altitude by soaring on a thermal updraft.
A “kettle” of Broad-winged Hawks gaining altitude by soaring on a thermal updraft.
Migrating Broad-winged Hawks
Broad-winged Hawks gliding away to the southwest after climbing in a column of rising warm air.
Broad-winged Hawk
A migrating Broad-winged Hawk enroute to the tropics for winter.

Other diurnal migrants are on the move as well…

Migratory Woodpeckers: Red-bellied Woodpecker and Northern Flicker
The Red-bellied Woodpecker (left) and the Northern Flicker (right) are migratory species of woodpeckers that begin heading south during the last half of September each year.
Migrating Blue Jay
Running a bit early, large numbers of Blue Jays having been moving through the area for several weeks now.
Flock of Cedar Waxwings
Flocks of Cedar Waxwings roam widely as they creep ever southward for winter.

Adding to the diversity of sightings, there are these diurnal raptors arriving in the area right now…

Juvenile Sharp-shinned Hawk
Numbers of migrating Sharp-shinned Hawks are building and will peak during the coming weeks.
Juvenile Cooper's Hawk
As will numbers of Cooper’s Hawks.
Merlin
The Merlin and other falcons peak in late September and early October.
Adult Bald Eagle
And Bald Eagles are moving throughout the fall season.

For more information and directions to places where you can observe migrating hawks and other birds, be certain to click the “Hawkwatcher’s Helper” tab at the top of this page.

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: "Taiga Merlin"
A “Taiga Merlin” (Falco columbarius columbarius) with an Eastern Kingbird snatched from midair.  Both these species are accomplished fliers that rely upon aerial pursuit to catch their prey, the former preferring small birds and the latter flying insects.

Broad-winged Hawk Flights Underway

The smoke has cleared—at least for now—and Broad-winged Hawks are being seen migrating across lower Susquehanna valley skies.  Check out these daily counts from area hawk watches…

    • Rocky Ridge County Park Hawk Watch northeast of York, Pennsylvania: 475 Broad-winged Hawks on Saturday, September 18th—including 388 during the two hours between noon and 2 P.M.
    • Second Mountain Hawk Watch at Fort Indiantown Gap in Lebanon County, Pennsylvania: 300 Broad-winged Hawks on Wednesday, September 15th— one more than was tallied passing the site on the previous day.
    • Waggoner’s Gap Hawk Watch on Blue Mountain north of Carlisle, Pennsylvania: 1,211 Broad-winged Hawks on Tuesday, September 14th and 1,485 on Sunday, September 19th.
Broad-winged hawks in a “kettle” formation gaining altitude on a thermal updraft above Second Mountain Hawk Watch before continuing on their migratory journey.  “Kettling” can occur above any heat-generating surface on a sunny day, even a parking lot.
A migrating adult Broad-winged Hawk rising skyward.
A juvenile Broad-winged Hawk “feeding on the wing” consuming a dragonfly.

Additional Broad-winged Hawks are still working their way through the Mid-Atlantic States as they continue toward tropical wintering grounds.  And there’s more.  Numbers for a dozen other migratory hawk, eagle, and falcon species will peak between now and mid-November.  Days following passage of a cold front are generally best—so do get out there and have a look!

You can check the daily hawk count numbers and find detailed information for lookout sites all across North America at hawkcount.org

And don’t forget to click the “Hawkwatcher’s Helper” tab at the top of this page to see a gallery of photos that can help you to identify, and possibly determine the age of, the many species of raptors that occur in the Lower Susquehanna River Watershed.

A juvenile Merlin clutching a dragonfly takes a late-afternoon break from its migration flight.  Merlin numbers peak in early October.

Shorebirds at Middle Creek

Late August and early September is prime time to see migrating shorebirds as they pass through the lower Susquehanna valley during their autumn migration, which, believe it or not, can begin as early as late June.  These species that are often assumed to spend their lives only near the seashore are regular visitors each fall as they make their way from breeding grounds in the interior of Canada to wintering sites in seacoast wetlands—many traveling as far south as Central and South America.

Low water levels on the Susquehanna River often coincide with the shorebird migration each year, exposing gravel and sand bars as well as vast expanses of muddy shorelines as feeding and resting areas for these traveling birds.  This week though, rain from the remnants of Tropical Storm Fred arrived to increase the flow in the Susquehanna and inundate most of the natural habitat for shorebirds.  Those on the move must either continue through the area without stopping or find alternate locations to loaf and find food.

The draining and filling of wetlands along the river and elsewhere in the region has left few naturally-occurring options.  The Conejohela Flats south of Columbia offer refuge to many migrating sandpipers and their allies, the river level there being controlled by releases from the Safe Harbor Dam during all but the severest of floods.  Shorebirds will sometimes visit flooded fields, but wide-open puddles and farmland resembling mudflats is more of springtime occurrence—preceding the planting and growth of crops.  Well-designed stormwater holding facilities can function as habitat for sandpipers and other wildlife.  They are worth checking on a regular basis—you never know what might drop in.

Right now, there is a new shorebird hot spot in the Lower Susquehanna River Watershed—Middle Creek Wildlife Management Area.  The water level in the main impoundment there has been drawn down during recent weeks to expose mudflats along the periphery of nearly the entire lake.  Viewing from “Stop 1” (the roadside section of the lake in front of the refuge museum) is best.  The variety of species and their numbers can change throughout the day as birds filter in and out—at times traveling to other mudflats around the lake where they are hidden from view.  The birds at “Stop 1” are backlit in the morning with favorable illumination developing in the afternoon.

Have a look at a few of the shorebirds currently being seen at Middle Creek…

The Killdeer is familiar as a breeding bird in the lower Susquehanna region.  Large numbers can congregate ahead of and during migration on mudflats and gravel bars.
The Least Sandpiper is one of the “peeps”, a group of very small shorebirds.  This species is quite common at Middle Creek right now.  Note the plants beginning to grow in the mud.  Later in the fall, after the shorebirds are gone, raising the water level in the lake will flood these newly vegetated areas to provide an abundance of food for migrating waterfowl.  This cycle can be repeated annually to support transient birds during what is often the most vulnerable time of their lives…fall migration.
The Baird’s Sandpiper (Calidris bairdii) is an uncommon “peep” along the east coast during autumn migration.  On the lower Susquehanna it is most frequently encountered on the vegetated gravel bars in mid-river during the last days of August or first days of September each year.  The mudflats and shallows at Middle Creek are providing a suitable alternative for this juvenile bird.
Numbers of Lesser Yellowlegs are increasing as flocks drop by for a rest and refueling.  Bring your binoculars and your spotting scope to see the oddities that may be hiding among these groups of newly-arriving migrants.

The aquatic environs at Middle Creek attract other species as well.   Here are some of the most photogenic…

Wood Ducks atop the dam.
The migration of Caspian Terns coincides with that of shorebirds.  Just look at that blood-red bill; it’s unmistakable.  Two of these big terns are currently patrolling Middle Creek’s lake and shoreline.
A female American Kestrel creates a stir among the “peeps” as it passes by.  The larger falcons (the Merlin and Peregrine) can be expected to more readily take advantage of concentrations of shorebirds as a food supply.
Osprey migration is underway, and many will stop at Middle Creek while in transit.
Even if shorebirds aren’t your thing, there are almost always Bald Eagles to be seen at Middle Creek.  See you there!

Migrating Golden Eagles

Why would otherwise sensible people perch themselves atop a rocky outcrop on a Pennsylvania mountaintop for ten hours on a windy bone-numbing bitter cold and sometimes snowy November day?  To watch migrating raptors of course.

November is the time when big hawks and eagles migrate through and into the lower Susquehanna valley.  And big birds rely on big wind to create updrafts and an easy ride along the region’s many ridges.  The most observable flights often accompany the arrival of cold air surging across the Appalachian Mountains from the northwest.  These conditions can propel season-high numbers of several of the largest species of raptors past hawk-counting sites.

Observers brave howling winds on the Waggoner’s Gap lookout to census migrating late-season raptors.

Earlier this week, two windy days followed the passage of a cold front to usher-in spectacular hawk and eagle flights at the the Waggoner’s Gap Hawk Watch station on Blue Mountain north of Carlisle, Pennsylvania.  Steady 30 M.P.H. winds from the northwest on Monday, November 2, gusted to 50 M.P.H. at times.  Early that morning, two Rough-legged Hawks, rarities at eastern hawk watches, were seen.  They and two American Goshawks (Astur atricapillus) provided a preview of the memorable sightings to come.  Two dozen Golden Eagles migrated past the lookout that day.  Then on November 3, thirty Golden Eagles were tallied, despite west winds at speeds not exceeding half those of the day before.

Here are some of the late-season raptors seen by hardy observers at Waggoner’s Gap on Monday and Tuesday, November 2 & 3.

In November, Red-tailed Hawks are the most common migratory raptor counted at hawk watch stations in the Susquehanna region.
 A juvenile American Goshawk passes the Waggoner's Gap lookout.
An uncommon bird, a juvenile American Goshawk, passes the Waggoner’s Gap lookout.
An adult Golden Eagle circles on an updraft along the north face of Blue Mountain to gain altitude before continuing on its journey.
The plumage of juvenile and immature Golden Eagles often creates a sensation among crowds at a lookout.  Golden Eagles don’t attain a full set of adult feathers until their sixth year.  This individual is probably a juvenile, also known as a hatch-year or first-year bird.  At most, it could be in its second year.  Click the “Golden Eagle Aging Chart” tab on this page to learn more about these uncommon migrants and their molt sequences as they mature.
The gilded head feathers of a Golden Eagle glisten in the afternoon sun.
An adult Golden Eagle passing Waggoner’s Gap.  The population known as “Eastern Golden Eagles” winters in the Appalachian Mountains and, with increasing frequency, on the Piedmont and Atlantic Coastal Plain Provinces of the eastern United States, where it often subsists as a scavenger.
Another first-year (juvenile) or second-year Golden Eagle.
A local Red-tailed Hawk (top left) trying to bully a migrating Golden Eagle.  A dangerous business indeed.
Through December, Bald Eagles, presently the more common of our eagle species, are regular migrants at Waggoner’s Gap and other Susquehanna valley hawk watch sites.
Red-shouldered Hawks are reliable early November migrants.
An adult Red-shouldered Hawk from above.
And an adult Red-shouldered Hawk from below.
Though their numbers peak in early October, Sharp-shinned Hawks, particularly adults like this one, continue to be seen through early November.
A Northern Harrier on the glide path overhead.
Merlins, like other falcons, are more apt to be seen in late September and October, but a few trickle through in November.

While visiting a hawk watch, one will certainly have the opportunity to see other birds too.

Common Ravens are fascinating birds and regular visitors to the airspace around hawk watches.  Most are residents, but there appears to be some seasonal movement, particularly among younger birds.
Most people think of Common Loons as birds of northern lakes.  But loons spend their winters in the ocean surf, and to get there they fly in loose flocks over the Lower Susquehanna River Watershed each spring and fall.  They are regularly seen by observers at hawk watches.
Like ducks, geese, and swans, migrating Double-crested Cormorants assemble into aerodynamic V-shaped flocks to conserve energy.
Pine Siskins continue their invasion from the north.  Dozens of small flocks numbering 10 to 20 birds each continue to be seen and/or heard daily at Waggoner’s Gap.  A flock of Evening Grosbeaks (Coccothraustes vesperitinus), another irruptive species of “winter finch”, was seen there on November 3.

As a finale of sorts, near the close of the day on November 3, two Golden Eagles sailed past the north side of the Waggoner’s Gap lookout, one possessing what appeared to be a tracking transmitter on its back.  An effort was commenced by the official count staff to report the sighting to the entity monitoring the bird—to track down the tracker, so to speak.

A Golden Eagle with a backpack transmitter passing Waggoner’s Gap Hawk Watch at 3:39 P.M. Eastern Standard Time on November 3, 2020.

To see the count reports from Waggoner’s Gap and other hawk watches throughout North America, be certain to visit hawkcount.org

A Visit to Second Mountain

If it can fly, there’s a pretty good chance it was at Second Mountain today.

What follows is a photographic chronology of some of today’s sightings at Second Mountain Hawk Watch at Fort Indiantown Gap in Lebanon County, Pennsylvania.  We begin with some of the hundreds of migratory songbirds found at the base of the mountain along Cold Spring Road near Indiantown Run during the early morning, then we continue to the lookout for the balance of the day.

A Black-and-white Warbler (Mniotilta varia) searching the trunk of a tree for insects.
A Rose-breasted Grosbeak.
A Blackburnian Warbler high in the forest canopy.
A Black-throated Green Warbler bouncing from branch to branch as it feeds.
A Chestnut-sided Warbler lurks among the foliage.
A Magnolia Warbler.
One of a hundred or more Red-eyed Vireos found swarming the treetops, and occasionally the understory, while engaging in a wild feeding frenzy.
A male American Redstart.  Judging by that gray hood, it’s probably experiencing its second fall migration.
Eyes were skyward at the Second Mountain Hawk Watch lookout as Broad-winged Hawks began streaming through during the mid-morning.
During the morning flight, Broad-winged Hawks including this adult floated by the lookout riding updrafts created by the south wind striking the face of the mountain ridge.
As the overcast became more scattered and more sunlight reached the ground, Broad-winged Hawks began riding thermal currents to gain altitude before gliding off to the southwest in continuance of their long trip to the tropics.  At times, birds would disappear into the base of the clouds before ending their climb and sailing away.
Broad-winged Hawks rely principally upon amphibians and large insects like this bush katydid (Scudderia species) for sustenance.  With freezing temperatures just around the corner, “broad-wings” must make their way to warmer climes early or risk starvation.
A Bald Eagle always gets observers looking.
A juvenile Broad-winged Hawk.
A juvenile Cooper’s Hawk.
A Broad-winged Hawk has a look around.
One never quite knows what one may see when having a look around.
A Cape May Warbler (Setophaga tigrina) in the lookout hemlock.
A Black Saddlebags, one of several migratory dragonflies seen today.
An Osprey glides through in the afternoon glare.
A speedy Merlin thrilled observers with a close approach.
One must remember that Fort Indiantown Gap is an active military installation, so from time to time training and drilling exercises may interrupt bird observation activities at the Second Mountain Hawk Watch.
Today, speedy A-10 Warthog attack aircraft piloted by members of the Maryland Air National Guard based at Glenn Martin Field thrilled observers on the lookout with several close passes during their training runs.
And repeat.
Drill complete.

The total number of Broad-winged Hawks observed migrating past the Second Mountain lookout today was 619.  To see the daily raptor counts for Second Mountain and other hawk watches in North America, and to learn more about each site, be sure to visit hawkcount.org

Bird Migration Highlights

The southbound bird migration of 2020 is well underway.  With passage of a cold front coming within the next 48 hours, the days ahead should provide an abundance of viewing opportunities.

Here are some of the species moving through the lower Susquehanna valley right now.

Blue-winged Teal are among the earliest of the waterfowl to begin southward migration.
Sandpipers and plovers have been on the move since July.  The bird in the foreground with these Killdeer is not one of their offspring, but rather a Semipalmated Plover (Charadrius semipalmatus), a regular late-summer migrant in the Lower Susquehanna River Watershed.
Hawk watch sites all over North America are counting birds right now.  The Osprey is an early-season delight as it glides past the lookouts.  Look for them moving down the Susquehanna as well.
Bald Eagles will be on the move through December.  To see these huge raptors in numbers, visit a hawk watch on a day following passage of a cold front when northwest winds are gusting.
Merlins were seen during this past week in areas with good concentrations of dragonflies.  This particular one at Middle Creek Wildlife Management Area in Lancaster and Lebanon Counties…
…was soon visited by another.
Check the forest canopy for Yellow-billed Cuckoos.  Some local birds are still on breeding territories while others from farther north are beginning to move through.
Ruby-throated Hummingbirds are darting through the lower Susquehanna valley on their way to the tropics.  This one has no trouble keeping pace with a passing Tree Swallow.
Nocturnal flights can bring new songbirds to good habitat each morning.  It’s the best time of year to see numbers of Empidonax flycatchers.  But, because they’re often silent during fall migration, it’s not the best time of year to easily identify them.  This one lacking a prominent eye ring is a Willow Flycatcher (Empidonax traillii).
During the past two weeks, Red-eyed Vireos have been numerous in many Susquehanna valley woodlands.  Many are migrants while others are breeding pairs tending late-season broods.
During mornings that follow heavy overnight flights, Blackburnian Warblers have been common among waves of feeding songbirds.
Chestnut-sided Warblers are regular among flocks of nocturnal migrants seen foraging among foliage at sunrise.
Scarlet Tanagers, minus the brilliant red breeding plumage of the males, are on their way back to the tropics for winter.
While passing overhead on their way south, Bobolinks can be seen or heard from almost anywhere in the lower Susquehanna valley.  Their movements peak in late August and early September.
During recent evenings, Bobolinks have been gathering by the hundreds in fields of warm-season grasses at Middle Creek Wildlife Management Area.
If you go to see the Bobolinks there, visit Stop 3 on the tour route late in the afternoon and listen for their call.  You’ll soon notice their wings glistening in the light of the setting sun as they take short flights from point to point while they feed.  Note the abundance of flying insects above the Big Bluestem and Indiangrass in this image.  Grasslands like these are essential habitats for many of our least common resident and migratory birds.

Look What the Wind Blew In

It’s been more than a week since Tropical Storm Isaias moved swiftly up the Atlantic seaboard leaving wind and flood damage in its wake.  Here in the Lower Susquehanna River Watershed, the brevity of its presence minimized the effects.

Tropical Storm Isaias moves north-northeast across the Delmarva Peninsula.

You may have noticed some summertime visitors flying about during these hot humid days that followed Isaias’ passing.  They’re the dragonflies.

Our familiar friend the Wandering Glider is widespread throughout the valley right now—dropping eggs on shiny automobile hoods that look to them like a nice quiet puddle of water.

The Wandering Glider is a global traveler.  Here in the lower Susquehanna valley, it is currently abundant around still water and in large parking lots.

Each of the other common migratory species is here too.  Look for them patrolling the skies over large bodies of water and over adjacent fallow land and meadows where tiny flying insects abound.  Did these dragonflies arrive on the winds associated with the tropical storm, or did they move in with the waves of warm air that followed it?  Probably a little of both.

The Common Green Darner, a large dragonfly, can be the most abundant of the migratory species.  Watch for high-flying swarms in the coming weeks.
The Black Saddlebags is recognized in flight by the black base of each hindwing.  These patches give the appearance of a pair of saddlebags draped across the dragonfly’s thorax.
The Twelve-spotted Skimmer(Libellula pulchella) is a regular migrant.
The Prince Baskettail (Epitheca princeps) can occur among mixed groups of dragonflies.  Despite it rarely being mentioned as a migrant, its proclivity for non-stop day-long flight makes it a likely sighting among sizeable swarms.

Big swarms of dragonflies don’t go unnoticed by predators—particularly birds.  The southbound migration of kites, Broad-winged Hawks, American Kestrels, and Merlins often coincides with the swarming of migratory dragonflies in late summer.  Each of these raptors will grab and feed upon these insects while on the wing—so keep an eye on the sky.

This Peregrine Falcon found the congregations of hundreds of dragonflies worthy of a closer look…
…and an acrobatic fly-by to disrupt the swarms.  Fun, fun, fun, fun, fun.

A Quick Getaway

It was a placid morning on Conewago Falls with blue skies dotted every now and then by a small flock of migrating robins or blackbirds.  The jumbled notes of a singing Winter Wren (Troglodytes hiemalis) in the Riparian Woodland softly mixed with the sounds of water spilling over the dam.  The season’s first Wood Ducks (Aix sponsa), Blue-winged Teal (Spatula discors), American Herring Gull (Larus smithsonianus), Horned Larks (Eremophila alpestris), and White-throated Sparrows (Zonotrichia albicollis) were seen.

There was a small ruckus when one of the adult Bald Eagles from a local pair spotted an Osprey passing through carrying a fish.  This eagle’s effort to steal the Osprey’s catch was soon interrupted when an adult eagle from a second pair that has been lingering in the area joined the pursuit.  Two eagles are certainly better than one when it’s time to hustle a skinny little Osprey, don’t you think?

But you see, this just won’t do.  It’s a breach of eagle etiquette, don’t you know?  Soon both pairs of adult eagles were engaged in a noisy dogfight.  It was fussing and cackling and the four eagles going in every direction overhead.  Things calmed down after about five minutes, then a staring match commenced on the crest of the dam with the two pairs of eagles, the “home team” and the “visiting team”, perched about 100 feet from each other.  Soon the pair which seems to be visiting gave up and moved out of the falls for the remainder of the day.  The Osprey, in the meantime, was able to slip away.

In recent weeks, the “home team” pair of Bald Eagles, seen regularly defending territory at Conewago Falls, has been hanging sticks and branched tree limbs on the cross members of the power line tower where they often perch.  They seem only to collect and display these would-be nest materials when the “visiting team” pair is perched in the nearby tower just several hundred yards away…an attempt to intimidate by homesteading.  It appears that with winter and breeding time approaching, territorial behavior is on the increase.

The second migrating Osprey of the day ran the gauntlet of marauding eagles without incident.

In the afternoon, a fresh breeze from the south sent ripples across the waters among the Pothole Rocks.  The updraft on the south face of the diabase ridge on the east shore was like a highway for some migrating hawks, falcons, and vultures.  Black Vultures (Coragyps atratus) and Turkey Vultures streamed off to the south headlong into the wind after leaving the ridge and crossing the river.  A male and female Northern Harrier (Circus hudsonius), ten Red-tailed Hawks, two Red-shouldered Hawks (Buteo lineatus), six Sharp-shinned Hawks, and two Merlins crossed the river and continued along the diabase ridge on the west shore, accessing a strong updraft along its slope to propel their journey further to the southwest.  Four high-flying Bald Eagles migrated through, each following the east river shore downstream and making little use of the ridge except to gain a little altitude while passing by.

(Top and Middle) Turkey Vultures riding the fresh breeze and teetering to-and-fro on up-tilted wings.  This wing posture is known as a dihedral.  (Bottom) More than 100 migrating Black Vultures climbed high on the afternoon breeze to make an oblique crossing of the river and maintain a southbound course.

Late in the afternoon, the local Bald Eagles were again airborne and cackling up a storm.  This time they intercepted an eagle coming down the ridge toward the river and immediately forced the bird to climb if it intended to pass.  It turned out to be the best sighting of the day, and these “home team” eagles found it first.  It was a Golden Eagle (Aquila chrysaetos) in crisp juvenile plumage.  On its first southward voyage, it seemed to linger after climbing high enough for the Bald Eagles to loose concern, then finally selected the ridge route and crossed the river to head off to the southwest.

Ring-billed Gulls began feeding during the afternoon as clouds preceding stormy weather approached.
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Swallows by the Thousands

A fresh breeze from the north brought cooler air and a reminder that summer is gone and autumn has arrived.

Fast-moving dark clouds provided a perfect backdrop for viewing passing diurnal migrants.  Bald Eagles utilized the tail wind to cruise down the Susquehanna toward Chesapeake Bay and points further south.  A migrating Merlin began a chase from which a Northern Flicker narrowly escaped by finding shelter among Pothole Rocks and a few small trees.  The season’s first American Black Duck (Anas rubripes), Common Loon (Gavia immer), Yellow-bellied Sapsucker (Sphyrapicus varia), and American Pipits (Anthus rubescens) moved through.

Blue Jays continued their hesitant crossings of the river at Conewago Falls.  The majority completed the journey by forming groups of a dozen or more birds and following the lead of a lone American Robin, a Northern Flicker, or, odd as it appeared, a small warbler.

By far the most numerous migrants today were swallows.  Thousands of Northern Rough-winged Swallows and hundreds of Tree Swallows were on the wing in search of what was suddenly a sparse flying insect supply.  To get out of the brisk wind, some of the more resourceful birds landed on the warm rocks.  To satisfy their appetite, many were able to pick crawling arthropods from the surface of the boulders.  They swallow them whole.

A few of the thousands of swallows seen at Conewago Falls today.
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Yellowlegs for Breakfast

A few nocturnal migrants flew through the moonlit night to arrive at Conewago Falls for a sunrise showing this morning.  A dozen warblers were in the treetops and a Wood Thrush (Hylocichla mustelina) chattered away in the understory of the Riparian Woodlands.  Three species of shorebirds were in the falls and on the Pothole Rocks: Least Sandpiper (Calidris minutilla), Lesser Yellowlegs (Tringa flavipes), and Greater Yellowlegs (Tringa melanoleuca).

A Greater Yellowlegs (right) and two Lesser Yellowlegs sandpipers dropped by for breakfast.

The diurnal migration was highlighted by a Merlin (Falco columbarius), an Osprey, and a Bald Eagle, each flying down the river.  Most of the other birds in the falls seemed content to linger and feed.  There’s no need to hurry folks, only trouble lurks down there in paradise at the moment.

A light to moderate flight of nocturnal migrants in the eastern United States is displayed on NOAA National Weather Service NEXRAD radar at 4:58 AM EDT.  The eye of Hurricane Irma can be seen approaching the Florida Keys.  (NOAA/National Weather Service image)
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