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.

An Encore of the Susquehanna Seawatch

In late March and early April, a rainy night and fog at daybreak can lead to an ideal morning for spotting migratory waterfowl and seabirds during their layover on the lower Susquehanna.  Visibility was just good enough to spot these birds at Harrisburg, Pennsylvania, most of them feeding at midriver.

Northern Shovelers are regular migrants, more often seen on ponds and in wetlands than on the river.
A pair of American Wigeons head upriver.
A Horned Grebe.
A small flock of northbound Buffleheads.
Ring-necked Ducks.
Lesser Scaup, eight of the more than 100 seen along Front Street in Harrisburg at the Pennsylvania Governor’s Residence.  Note how the white bar on the wing’s secondaries becomes diffused and dusky in the primaries.
Lesser Scaup spend the winter on bays and lakes to our south.
More Scaup, the lead bird with bright white extending through the secondaries into the primaries is possibly a Greater Scaup (Aythya marila).
Long-tailed Ducks, formerly known as Oldsquaw, are a diving duck that winters on the Great Lakes and on bays along the Atlantic Coast.  They nest on freshwater ponds and lakes in the tundra of Canada and Alaska.
A male Common Merganser.
This pair of Hooded Mergansers may be nesting in a tree cavity nearby.
The local Peregrine Falcon grabbed a passing Common Grackle…
…prompting the more than 100 Bonaparte’s Gulls in the vicinity to quickly depart and fly upstream.
Birds of Conewago Falls in the Lower Susquehanna River Watershed: Northern Flicker
It pays to keep an eye on the trees along the shoreline too.  Migrants like this Northern Flicker are beginning to come through in numbers.

Five Best Values for Feeding Birds

Despite being located in an urbanized downtown setting, blustery weather in recent days has inspired a wonderful variety of small birds to visit the garden here at the susquehannawildlife.net headquarters to feed and refresh.  For those among you who may enjoy an opportunity to see an interesting variety of native birds living around your place, we’ve assembled a list of our five favorite foods for wild birds.

American Goldfinches in drab winter (basic) plumage visit the trickle of water entering the headquarters pond to bathe and drink.  In addition to offering the foods animals need to survive, a source of clean water is an excellent way to attract wildlife to your property.

The selections on our list are foods that provide supplemental nutrition and/or energy for indigenous species, mostly songbirds, without sustaining your neighborhood’s non-native European Starlings and House Sparrows, mooching Eastern Gray Squirrels, or flock of ecologically destructive hand-fed waterfowl.  We’ve included foods that aren’t necessarily the cheapest but are instead those that are the best value when offered properly.

Bread, “bargain” seed mixes, and cracked corn can attract and sustain large numbers of House Sparrows and European Starlings.  Both are non-native species that compete mercilessly with indigenous birds including bluebirds for food and nesting sites.  Though found favorable for feeding Northern Cardinals without attracting squirrels, the expensive safflower seed seen here is another favorite of these aggressive House Sparrows.  Ever wasteful, they “shovel” seed out of feeders while searching for the prime morsels from which they can easily remove the hulls.  Trying not to feed them is an ongoing challenge, so we don’t offer these aforementioned foods to our avian guests.

Number 5

Raw Beef Suet

In addition to rendered beef suet, manufactured suet cakes usually contain seeds, cracked corn, peanuts, and other ingredients that attract European Starlings, House Sparrows, and squirrels to the feeder, often excluding woodpeckers and other native species from the fare.  Instead, we provide raw beef suet.

Because it is unrendered and can turn rancid, raw beef suet is strictly a food to be offered in cold weather.   It is a favorite of woodpeckers, nuthatches, and many other species.  Ask for it at your local meat counter, where it is generally inexpensive.

Raw beef suet is fat removed from areas surrounding the kidneys on a beef steer.  To avoid spoiling, offer it only in the winter months, particularly if birds are slow to consume the amount placed for them.  If temperatures are above freezing, it’s important to replace uneaten food frequently.  The piece seen here on the left was stored in the freezer for almost a year while the rancid piece to the right was stored in a refrigerator at about 40 degrees Fahrenheit for just two months.  You can render raw beef suet and make your own cakes by melting it down and pouring it into a form such as cupcake tin.  But do it outdoors or you’ll be living alone for a while.
A female Downy Woodpecker feeds on raw beef suet stuffed into holes drilled into a vertically hanging log.  Because they can’t be cleaned, log feeders should be discarded after one season.  Wire cage feeders though, can usually be scrubbed, disinfected, dried, and reused.
Pesky European Starlings might visit a raw beef suet feeder but won’t usually linger unless other foods to their liking are available nearby.
This male Downy Woodpecker has no trouble feeding on raw beef suet packed into holes drilled into the underside of this horizontally hanging log.  Starlings don’t particularly care to feed this way.
Unusual visitors like a Brown Creeper are more likely to stop by at a suet feeder when it isn’t crowded by raucous starlings, House Sparrows, and squirrels.   This one surprised us just this morning.
Below the feeders, scraps of suet that fall to the ground are readily picked up, usually by ground-feeding birds.  In this instance, a male Eastern Bluebird saw a chunk break loose and pounced on it with haste.

Number 4

Niger (“Thistle”) Seed

Niger seed, also known as nyjer or nyger, is derived from the sunflower-like plant Guizotia abyssinica, a native of Ethiopia.  By the pound, niger seed is usually the most expensive of the bird seeds regularly sold in retail outlets.  Nevertheless, it is a good value when offered in a tube or wire mesh feeder that prevents House Sparrows and other species from quickly “shoveling” it to the ground.  European starlings and squirrels don’t bother with niger seed at all.

Niger seed must be kept dry.  Mold will quickly make niger seed inedible if it gets wet, so avoid using “thistle socks” as feeders.  A dome or other protective covering above a tube or wire mesh feeder reduces the frequency with which feeders must be cleaned and moist seed discarded.  Remember, keep it fresh and keep it dry!

Niger (“thistle”) seed is very small, so it is offered in specialized feeders to prevent seed from spilling out of oversize holes as waste.
An American Goldfinch in winter plumage feeding on niger seed from a wire mesh feeder.  By April, goldfinches are molting into spectacular breeding feathers.  Niger seed can be offered year-round to keep them visiting your garden while they are at maximum magnificence.
American Goldfinches in August.  This tube feeder is designed specifically for goldfinches, birds that have no difficulty hanging upside down to grab niger seed from small feeding ports.
During invasion years, visiting Pine Siskins favor niger seed at feeding stations.
Like goldfinches, Pine Siskins are quite comfortable feeding upside down on specialized tubes with perches positioned above the seed ports.  Seeds dropped to the ground are readily picked up by ground-feeding birds including Mourning Doves and Dark-eyed Juncos.  Periodically, uneaten niger seed should be swept up and discarded.

Number 3

Striped Sunflower Seed

Striped sunflower seed, also known as grey-striped sunflower seed, is harvested from a cultivar of the Common Sunflower (Helianthus annuus), the same tall garden plant with a massive bloom that you grew as a kid.  The Common Sunflower is indigenous to areas west of the Mississippi River and its seeds are readily eaten by many native species of birds including jays, finches, and grosbeaks.  The husks are harder to crack than those of black oil sunflower seed, so House Sparrows consume less, particularly when it is offered in a feeder that prevents “shoveling”.   For obvious reasons, a squirrel-proof or squirrel-resistant feeder should be used for striped sunflower seed.

Striped sunflower seed.
A male House Finch and a Carolina Chickadee pluck striped sunflower seeds from a squirrel-resistant powder-coated metal-mesh tube feeder.
An American Goldfinch in winter plumage finds striped sunflower seeds irresistible, even with niger seed being offered in an adjacent feeder.
A Tufted Titmouse visits a feeder stocked with striped sunflower seeds.
Northern Cardinals readily feed on striped sunflower seeds, especially those that fall from our metal-mesh tube feeders.
An Eastern Gray Squirrel (Sciurus carolinensis) has no choice but to be satisfied with striped sunflower seeds that spill from our wire-mesh tube feeders.

Number 2

Mealworms

Mealworms are the commercially produced larvae of the beetle Tenebrio molitor.  Dried or live mealworms are a marvelous supplement to the diets of numerous birds that might not otherwise visit your garden.  Woodpeckers, titmice, wrens, mockingbirds, warblers, and bluebirds are among the species savoring protein-rich mealworms.  The trick is to offer them without European Starlings noticing or having access to them because European Starlings you see, go crazy over a meal of mealworms.

Dried mealworms can be offered in a cup or on a tray feeder.  Live mealworms need to be contained in a steep-sided dish, so they don’t crawl away.  Unless you’re really lucky, you’ll probably have to place your serving vessel of mealworms inside some type of enclosure to exclude European Starlings.
A male Eastern Bluebird tossing and grabbing a dried mealworm.
A female Eastern Bluebird with a dried mealworm.
A pair of Eastern Bluebirds.  The value of mealworms is self-evident: you get to have bluebirds around.

 

To foil European Starlings, we assembled this homemade mealworm feeder from miscellaneous parts. The bluebirds took right to it.
It frustrates the starlings enough to discourage them from sticking around for long.
If you’re offering dried mealworms, a source of clean water must be available nearby so that the bluebirds and other guests at your feeder don’t become dehydrated.

Number 1

Food-producing Native Shrubs and Trees

The best value for feeding birds and other wildlife in your garden is to plant food-producing native plants, particularly shrubs and trees.  After an initial investment, they can provide food, cover, and roosting sites year after year.  In addition, you’ll have a more complete food chain on a property populated by native plants and all the associated life forms they support (insects, spiders, etc.).

In your garden, a Northern Mockingbird may defend a food supply like these Common Winterberry fruits as its sole means of sustenance for an entire winter season.  Having an abundance of plantings assures that in your cache there’s plenty to eat for this and other species.
The American Goldfinches currently spending the winter at our headquarters are visiting the feeders for niger and striped sunflower seeds, but the bulk of their diet consists of tiny seeds from the cones on our Eastern Hemlock trees.  At night, birds obtain shelter from the weather by roosting in this clump of evergreens.
While the Eastern Bluebirds visiting the susquehannawildlife.net headquarters are fond of mealworms, the bulk of their diet here consists of these Common Winterberry fruits and the berries on our American Holly trees.
Cedar Waxwings are readily attracted to red berries including Common Winterberry fruit.
Migrating American Robins visit the headquarters garden in late winter each year to devour berries before continuing their journey to the north.

Your local County Conservation District is having its annual spring tree sale soon.  They have a wide selection to choose from each year and the plants are inexpensive.  They offer everything from evergreens and oaks to grasses and flowers.  You can afford to scrap the lawn and revegetate your whole property at these prices—no kidding, we did it.  You need to preorder for pickup in the spring.  To order, check their websites now or give them a call.  These food-producing native shrubs and trees are by far the best bird feeding value that you’re likely to find, so don’t let this year’s sales pass you by!

Photo of the Day

A Pileated Woodpecker devours the dark blue berries of a Black Gum (Nyssa sylvatica). The Black Gum, also known as the Black Tupelo, Sour Gum, and Pepperidge, sports crimson leaves in the fall to attract birds to its fruit, thus assuring distribution of its seeds.  In 2021, the fruit is so abundant that it has outlasted the foliage, much to the delight of resident and migrating birds.

Photo of the Day

A juvenile Red-headed Woodpecker surveys the morning landscape.  In the lower Susquehanna watershed, Red-headed Woodpeckers are an uncommon summer breeder requiring large dead oak trees in semi-open habitat for nesting.  They can occasionally be found during winter in mature oak woods, appearing most frequently west of the river at places including Gifford Pinchot State Park.  Fall migrants are seen along local ridges in September and October.

Migration Update

Can it be that time already?  Most Neotropical birds have passed through the Lower Susquehanna River Watershed on their way south and the hardier species that will spend our winter in the more temperate climes of the eastern United States are beginning to arrive.

Here’s a gallery of sightings from recent days…

During the past two weeks, thousands of Broad-winged Hawks, including this adult bird, crossed the skies of the lower Susquehanna valley on their way to Central and South America for our winter.
A juvenile Broad-winged Hawk passes into the sunset during its first autumn migration.
Blackpoll Warblers are among the last of the Neotropical species to transit the region.  They’ll continue to be seen locally through at least early October.
Blue-headed Vireos are the October vireo during the fall, the other species having already continued toward tropical forests for a winter vacation.
The lower Susquehanna region lies just on the northern edge of the wintering range of the Blue-gray Gnatcatcher, a species found nesting locally among treetops in deciduous woods.  Look for their numbers to swell in coming days as birds from further north begin rolling through the region on their way south.
Sharp-shinned Hawks delight visitors at ridgetop hawk watches during breezy late-September and early-October days.  They allow closer observation than high-flying Broad-winged Hawks due to their habit of cruising just above the treetops while migrating.
A Sharp-shinned Hawk glides over a lookout.
Late September/early October is falcon time at area hawk-counting stations, the Peregrine Falcon often being the most anticipated species.
Pale “Tundra Peregrines”, a subspecies that nests in the arctic, are strictly migratory birds in the Mid-Atlantic States.  They are presently passing through on their way to South America.  Like Neotropical songbirds, their long flights provide them with the luxury of never experiencing a winter season.
This Carolina Saddlebags and other migratory dragonflies, which normally leave the area by mid-September, are still lingering in the lower Susquehanna region, much to the pleasure of the falcons that feed upon them.
An male American Kestrel in pursuit of dragonflies found swarming around the lookout at Second Mountain Hawk Watch in Lebanon County, Pennsylvania.
A male American Kestrel stooping on a dragonfly.
Osprey will be among the birds of prey passing hawk watch sites during the coming two weeks.  The first week of October often provides the best opportunity for seeing the maximum variety of raptors at a given site.  On a good day, a dozen species are possible.
Seeing cinnamon-colored juvenile Northern Harriers is symbolic of the October migration flights.
Bald Eagles always thrill the crowd.
In addition to raptors, resident Common Ravens are regularly sighted by observers at hawk watches and elsewhere during the fall season.
Hawk-counting stations sometimes log movements of Red-bellied Woodpeckers during late September and early October.  This species has extended its range into the Lower Susquehanna River Watershed only during the past one hundred years, making these seasonal migration movements a recent local phenomenon.
Blue Jays are currently on the move with breeding birds from the forests of Canada and the northern United States moving south.  Hundreds can be seen passing a given observation point during an ideal morning.
Blue Jays find a pile of peanuts to be an irresistible treat.  Provide the unsalted variety and watch the show!

Be sure to click on these tabs at the top of this page to find image guides to help you identify the dragonflies, birds, and raptors you see in the Lower Susquehanna River Watershed…

    • Damselflies and Dragonflies
    • Birds of Conewago Falls
    • Hawkwatcher’s Helper: Identifying Bald Eagles and other Raptors

See you next time!

Coming Soon, Very Soon: Brood X Periodical Cicadas

Yesterday, a hike through a peaceful ridgetop woods in the Furnace Hills of southern Lebanon County resulted in an interesting discovery.  It was extraordinarily quiet for a mid-April afternoon.  Bird life was sparse—just a pair of nesting White-breasted Nuthatches and a drumming Hairy Woodpecker.  A few deer scurried down the hillside.  There was little else to see or hear.  But if one were to have a look below the forest floor, they’d find out where the action is.

Not much action in the deer-browsed understory of this stand of hardwoods.
Upon discovery beneath a rock, this invertebrate quickly backed its way down the burrow, promptly seeking shelter in the underground section of the excavation.
A closeup of the same image reveals the red eyes of this Periodical Cicada (Magicicada species) nymph.  It has reached the end of seventeen years of slowly feeding upon the sap from a tree root to nourish its five instars (stages) of larval development.

2021 is an emergence year for Brood X, the “Great Eastern Brood”—the largest of the 15 surviving broods of Periodical Cicadas.  After seventeen years as subterranean larvae, the nymphs are presently positioned just below ground level, and they’re ready to see sunlight.  After tunneling upward from the deciduous tree roots from which they fed on small amounts of sap since 2004, they’re awaiting a steady ground temperature of about 64 degrees Fahrenheit before surfacing to climb a tree, shrub, or other object and undergo one last molt into an imago—a flying adult.

Here, approximately one dozen Periodical Cicada nymphs have tunneled into pre-emergence positions beneath a rock.  Seventeen-year Periodical Cicadas, sometimes mistakenly called “seventeen-year locusts”, are the longest-lived of our insects.
Note the wings and red eyes beneath the exoskeleton of this Periodical Cicada nymph. Within weeks it will join billions of others in a brief emergence to molt, dry, fly, mate, and die.
Adult (imago) Periodical Cicadas.  Brood X includes all three species of seventeen-year Periodical Cicadas: Magicicada septendecim, M. cassinii, and M. septendecula.  All Periodical Cicadas in the United States are found east of the Great Plains, the lack of trees there prohibiting the expansion of their range further west.  Seventeen-year life cycles account for twelve of the fifteen broods of Periodical Cicadas; the balance live for thirteen years.  The range of Brood X includes the lower Susquehanna basin and parts of Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, Ohio, Tennessee, Virginia, West Virginia, and the District of Columbia.  (United States Department of Agriculture/Agricultural Research Service image)
The flight of Periodical Cicadas peaks in late-May and June.  Annual Cicadas like this Silver-bellied Cicada emerge later in the season, peaking yearly in July and August,

The woodlots of the Lower Susquehanna River Watershed won’t be quiet for long.  Loud choruses of male Periodical Cicadas will soon roar through forest and verdant suburbia.  They’re looking for love, and they’re gonna die trying to find it.  And dozens and dozens of animal species will take advantage of the swarms to feed themselves and their young.  Yep, the woods are gonna be a lively place real soon.

Did you say Periodical Cicadas?  We can hardly wait!

Forest vs. Woodlot

Let’s take a quiet stroll through the forest to have a look around.  The spring awakening is underway and it’s a marvelous thing to behold.  You may think it a bit odd, but during this walk we’re not going to spend all of our time gazing up into the trees.  Instead, we’re going to investigate the happenings at ground level—life on the forest floor.

Rotting logs and leaf litter create the moisture retaining detritus in which mesic forest plants grow and thrive.  Note the presence of mosses and a vernal pool in this damp section of forest.
The earliest green leaves in the forest are often those of the Skunk Cabbage (Simplocarpus foetidus).  This member of the arum family gets a head start by growing in the warm waters of a spring seep or in a stream-fed wetland.  Like many native wildflowers of the forest, Skunk Cabbage takes advantage of early-springtime sun to flower and grow prior to the time in late April when deciduous trees grow foliage and cast shade beneath their canopy.
Among the bark of dead and downed trees, the Mourning Cloak butterfly (Nymphalis antiopa) hibernates for the winter.  It emerges to alight on sun-drenched surfaces in late winter and early spring.
Another hibernating forest butterfly that emerges on sunny early-spring days is the Eastern Comma (Polygonia comma), also known as the Hop Merchant.
In a small forest brook, a water strider (Gerridae) chases its shadow using the surface tension of the water to provide buoyancy.  Forests are essential for the protection of headwaters areas where our streams get their start.
Often flooded only in the springtime, fish-free pools of water known as vernal ponds are essential breeding habitat for many forest-dwelling amphibians.  Unfortunately, these ephemeral wetland sites often fall prey to collecting, dumping, filling, and vandalism by motorized and non-motorized off-roaders, sometimes resulting in the elimination of the populations of frogs, toads, and salamanders that use them.
Wood Frogs (Lithobates sylvaticus) emerge from hiding places among downed timber and leaf litter to journey to a nearby vernal pond where they begin calling still more Wood Frogs to the breeding site.
Wood Frog eggs must hatch and tadpoles must transform into terrestrial frogs before the pond dries up in the summertime.  It’s a risky means of reproduction, but it effectively evades the enormous appetites of fish.
When the egg laying is complete, adult Wood Frogs return to the forest and are seldom seen during the rest of the year.
In early spring, Painted Turtles emerge from hideouts in larger forest pools, particularly those in wooded swamps, to bask in sunny locations.
Dead standing trees, often called snags, are essential habitats for many species of forest wildlife.  There is an entire biological process, a micro-ecosystem, involved in the decay of a dead tree.  It includes fungi, bacteria, and various invertebrate animals that reduce wood into the detritus that nourishes and hydrates new forest growth.
Birds like this Red-headed Woodpecker feed on insects found in large snags and nest almost exclusively in them.  Many species of wildlife rely on dead trees, both standing and fallen, during all or part of their lives.

There certainly is more to a forest than the living trees.  If you’re hiking through a grove of timber getting snared in a maze of prickly Multiflora Rose (Rosa multiflora) and seeing little else but maybe a wild ungulate or two, then you’re in a has-been forest.  Logging, firewood collection, fragmentation, and other man-made disturbances inside and near forests take a collective toll on their composition, eventually turning them to mere woodlots.  Go enjoy the forests of the lower Susquehanna valley while you still can.  And remember to do it gently; we’re losing quality as well as quantity right now—so tread softly.

The White-tailed Deity in a woodlot infested by invasive tangles of Multiflora Rose.

October Transition

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

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

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

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

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

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

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

Get Away From It All

For those of you who dare to shed that filthy contaminated rag you’ve been told to breathe through so that you might instead get out and enjoy some clean air in a cherished place of solitude, here’s what’s around—go have a look.

Northern Flickers have arrived.  Look for them anywhere there are mature trees.  Despite the fact that flickers are woodpeckers, they often feed on the ground.  You’ll notice the white rump and yellow wing linings when they fly away.
The tiny Chipping Sparrow frequently nests in small trees in suburban gardens.  Lay off the lawn treatments to assure their success.
Field Sparrows (Spizella fusilla) are a breeding species in abandoned fields where successional growth is underway.
White-throated Sparrows spend the winter in the lower Susquehanna valley.  Their numbers are increasing now as waves of migrants pass through on their way north.
Northbound flocks of Rusty Blackbirds (Euphagus carolinus) are currently found feeding in forest swamps along the Susquehanna.  Their noisy calls sound like a chorus of squeaking hinges.
Migratory Red-shouldered Hawks are also making feeding stops at area wetlands.
The Palm Warbler (Setophaga palmarum) is easily identified by its tail pumping behavior.  Look for it in shrubs along the river shoreline or near lakes and streams.  Palm Warblers are among the earliest of the warblers to move through in the spring.

The springtime show on the water continues…

Common Loons will continue migrating through the area during the upcoming month.
Buffleheads are still transiting the watershed.
Horned Grebes are occurring on the river and on local lakes.
Seeing these one-year-old male Hooded Mergansers, the bachelors, wandering around without any adult males or females is a good sign.  The adults should have moved on to the breeding grounds and local pairs should be well into a nesting cycle by now.  Hatching could occur any day.
Like Hooded Mergansers, Wood Ducks are cavity nesters, but their egg laying, incubation, and hatching often occurs a month or more later than that of the hoodies.  Judging by the attentiveness of the drake, this pair of woodies is probably in the egg-laying stage of its breeding cycle right now.
Redheads (Aythya americana) are stopping for a rest on their way north.
In spring, Double-crested Cormorants proceed up the river in goose-like flocks with adult birds like these leading the way.

Hey, what are those showy flowers?

That’s Lesser Celandine (Ficaria verna).  It’s often called Fig Buttercup.  In early April it blankets stream banks throughout the lower Susquehanna region.  If you don’t remember seeing it growing like that when you were younger, there’s a reason.  Lesser Celandine is an escape from cultivation that has become invasive.  While the appearance is tolerable; it’s the palatability that ruins everything.  It’s poisonous if eaten by people or livestock.
The Eastern Spring Beauty (Claytonia virginica) is a dainty native wildflower of riparian forests and other woodlands throughout the lower Susquehanna valley.
The Trout Lily (Erythronium americanum) is beginning to bloom now.  It’s a native of the region’s damp forests.
Virginia Bluebells (Mertensia virginica) is not native to the Susquehanna watershed, but neither is it considered invasive.  It creates colorful patches in riparian forests.
Dutchman’s Breeches (Dicentra cucullaria) is a strikingly beautiful native wildflower that grows on undisturbed forested slopes throughout the Susquehanna valley.

Wasn’t that refreshing?  Now go take a walk.

A Springtime Quiz

The mild winter has apparently minimized weather-related mortality for the local Green Frog population.  With temperatures in the seventies throughout the lower Susquehanna valley for this first full day of spring, many recently emerged adults could be seen and, on occasion, heard.  Yellow-throated males tested their mating calls—reminding the listener of the sound made by the plucking of a loose banjo string.

Here’s a gathering of Green Frogs seen this afternoon along the edge of a small pond.  How many can you find in this photograph?

If you venture out, keep alert for the migrating birds of late winter and early spring.

Yellow-bellied Sapsuckers are moving through on their way north.  Look for them in mature trees in woodlands, suburbs, and city parks.
The Fox Sparrow (Passerella iliaca), our largest sparrow, is a thrush-like denizen of shrubby forest understories and field edges.  It is an early spring and late autumn transient in the lower Susquehanna valley.
While stopping to rest and feed during their northbound spring journey, Ring-necked Ducks and other diving duck species visit wetlands and flooded timber along the Susquehanna River as well as clear ponds and lakes elsewhere in the watershed.
Eastern Bluebirds are presently migrating through the area.  Some will stay to breed where nest boxes or natural cavities are available in suitable habitat.
Tree Swallows are now arriving.  In open grasslands, pastures, and adjacent to almost any body of water, they will nest in boxes like those placed for bluebirds.
Keep that bird bath clean and fill it with fresh water, the American Robin flights are peaking right now.  Breeding males like this one are starting to sing and defend nesting territories.
Red-winged Blackbirds, like other native blackbirds, are moving through in a fraction of the numbers that were seen in the lower Susquehanna valley during the latter decades of the twentieth century.  They remain a common breeding species in pastures and cattail wetlands.
And of course, keep an eye to the sky.  There are still thousands of Snow Geese in the area.

If you’re staying close to home, be sure to check out the changing appearance of the birds you see nearby.  Some species are losing their drab winter basic plumage and attaining a more colorful summer breeding alternate plumage.

European Starlings are losing their spotted winter (basic) plumage and beginning to display a glossy multicolored set of breeding feathers.
An American Goldfinch in transition from winter (basic) plumage to bright yellow, black, and white summer colors.

So just how many Green Frogs were there in that first photograph?  Here’s the answer.

If you counted seven, you did really well.  Numbers eight and nine are very difficult to discern.

Happy Spring.  For the benefit of everyone’s health, let’s hope that it’s a hot and humid one!

Clean Slate for 2020

Inside the doorway that leads to your editor’s 3,500 square foot garden hangs a small chalkboard upon which he records the common names of the species of birds that are seen there—or from there—during the year.  If he remembers to, he records the date when the species was first seen during that particular year.  On New Year’s Day, the results from the freshly ended year are transcribed onto a sheet of notebook paper.  On the reverse, the names of butterflies, mammals, and other animals that visited the garden are copied from a second chalkboard that hangs nearby.  The piece of paper is then inserted into a folder to join those from previous New Year’s Days.  The folder then gets placed back into the editor’s desk drawer beneath a circular saw blade and an old scratched up set of sunglasses—so that he knows exactly where to find it if he wishes to.

A quick glance at this year’s list calls to mind a few recollections.

The 2019 bird list included 48 species, the 47 on the board plus Ruby-throated Hummingbird, which was logged on a slip of paper found tucked into the edge of the frame.

This Green Frog, photographed on New Year’s Day 2019, was “out and about” along the edge of the editor’s garden pond.  Due to the recent mild weather, Green Frogs were active during the current New Year’s holiday as well.
On a day with strong south winds in late February or during the first two weeks of March, there is often a conspicuous northbound spring flight of migrating waterfowl, gulls, and songbirds that crosses the lower Susquehanna valley as it departs Chesapeake Bay.  These Tundra Swans were among the three thousand seen from the garden patio on March 13, 2019.  A thousand migrating Canada Geese, 500 Red-winged Blackbirds, numerous Ring-billed Gulls, and some Herring Gulls were seen during the same afternoon.
This juvenile Cooper’s Hawk was photographed through the editor’s kitchen window.  From its favorite perch on this arbor it would occasionally find success snagging a House Sparrow from the large local flock.  It first visited the garden in November, the species being absent there since early spring.  Unlike previous years, there was no evidence of a breeding pair in the vicinity during 2019.
Plantings that provide food and cover for wildlife are essential to their survival.  Native flowers including Trumpet Vine (Campsis radicans) and Partridge Pea provide nourishment for the Ruby-throated Hummingbirds that visit the editor’s garden, but they really love a basket or pot filled with Mexican Cigar (Cuphea ignea) too.  The latter (seen here) can be grown as a houseplant and moved outdoors to a semi-shaded location in summer and early fall.  But remember, it’s tropical, so you’ll need to bring it back inside when frost threatens.
A Swamp Sparrow is an unusual visitor to a small property surrounded by paved parking lots and treeless lawns.  Nevertheless, aquatic gardens and native plants helped to attract this nocturnal migrant, seen here eating seeds from Indiangrass.  It arrived on September 30 and was gone on October 2.

Before putting the folder back into the drawer for another year, the editor decided to count up the species totals on each of the sheets and load them into the chart maker in the computer.

Despite the habitat improvements in the garden, the trend is apparent.  Bird diversity has not cracked the 50 species mark in 6 years.  Despite native host plants and nectar species in abundance, butterfly diversity has not exceeded 10 species in 6 years.

It appears that, at the very least, the garden habitat has been disconnected from the home ranges of many species by fragmentation.  His little oasis is now isolated in a landscape that becomes increasingly hostile to native wildlife with each passing year.  The paving of more parking areas, the elimination of trees, shrubs, and herbaceous growth from the large number of rental properties in the area, the alteration of the biology of the nearby stream by hand-fed domestic ducks, light pollution, and the outdoor use of pesticides have all contributed to the separation of the editor’s tiny sanctuary from the travel lanes and core habitats of many of the species that formerly visited, fed, or bred there.  In 2019, migrants, particularly “fly-overs”, were nearly the only sightings aside from several woodpeckers, invasive House Sparrows (Passer domesticus), and hardy Mourning Doves.  Even rascally European Starlings became sporadic in occurrence—imagine that!   It was the most lackluster year in memory.

The Tufted Titmouse was a daily visitor to the garden through 2018.  This one was photographed investigating holes in an old magnolia there during the spring of that year.  There were no Tufted Titmouse sightings in the garden in 2019.  This and other resident species, especially cavity-nesters, appear to be experiencing at least a temporary decline.
Breeding birds including Northern Cardinals may have had a difficult year.  In the editor’s garden, a pair were still feeding and escorting one of their young in early October.  The infestation of the editor’s town by domestic house and feral cats may have contributed to the failure of earlier broods, but a lack of food is also a likely factor.

If habitat fragmentation were the sole cause for the downward trend in numbers and species, it would be disappointing, but comprehendible.  There would be no cause for greater alarm.  It would be a matter of cause and effect.  But the problem is more widespread.

Although the editor spent a great deal of time in the garden this year, he was also out and about, traveling hundreds of miles per week through lands on both the east and the west shores of the lower Susquehanna.  And on each journey, the number of birds seen could be counted on fingers and toes.  A decade earlier, there were thousands of birds in these same locations, particularly during the late summer.

At about the time of summer solstice in June each year, Common Grackles begin congregating into roving summer flocks that will grow in size to assure their survival during the autumn migration, winter season, and return north in the spring.  From his garden, the editor saw just one flock of less than a dozen birds during the summer of 2019.  He saw none during his journeys through other areas of the Susquehanna valley.  Flocks of one hundred birds or more did not materialize until the southbound movements of grackles passed through the region in October and November.

In the lower Susquehanna valley, something has drastically reduced the population of birds during breeding season, post-breeding dispersal, and the staging period preceding autumn migration.  In much of the region, their late-spring through summer absence was, in 2019, conspicuous.  What happened to the tens of thousands of swallows that used to gather on wires along rural roads in August and September before moving south?  The groups of dozens of Eastern Kingbirds (Tyrannus tyrannus) that did their fly-catching from perches in willows alongside meadows and shorelines—where are they?

Several studies published during the autumn of 2019 have documented and/or predicted losses in bird populations in the eastern half of the United States and elsewhere.  These studies looked at data samples collected during recent decades to either arrive at conclusions or project future trends.  They cite climate change, the feline infestation, and habitat loss/degradation among the factors contributing to alterations in range, migration, and overall numbers.

There’s not much need for analysis to determine if bird numbers have plummeted in certain Lower Susquehanna Watershed habitats during the aforementioned seasons—the birds are gone.  None of these studies documented or forecast such an abrupt decline.  Is there a mysterious cause for the loss of the valley’s birds?  Did they die off?  Is there a disease or chemical killing them or inhibiting their reproduction?  Is it global warming?  Is it Three Mile Island?  Is it plastic straws, wind turbines, or vehicle traffic?

The answer might not be so cryptic.  It might be right before our eyes.  And we’ll explore it during 2020.

A clean slate for 2020.

In the meantime, Uncle Ty and I going to the Pennsylvania Farm Show in Harrisburg.  You should go too.  They have lots of food there.

No Need to Hurry

It’s that time of year when one may expect to find migratory Neotropical songbirds feeding among the foliage of trees and shrubs in the forests, woodlots, and thickets of the lower Susquehanna valley.

During a late afternoon stroll through a headwaters forest east of Conewago Falls outside Mount Gretna, I was pleased to finally come upon a noisy gathering of about two dozen birds.  It had, previous to that, been a quiet two hours of walking, only the rumble of an approaching thunderstorm punctuated the silence.  Among this little flock were some chickadees, robins, Gray Catbirds, an Eastern Towhee (Pipilo erythrophthalmus), and a Hairy Woodpecker (Dryobates villosus).  Besides the catbirds, there were two other species of Neotropical migrants; both were warblers.  No less than six Black-throated Blue Warblers (Setophaga caerulescens) were  vying for positions in the trees from which they could investigate the stranger on the footpath below.  And among the understory shrubs there were at least as many Ovenbirds (Seiurus aurocapilla) satisfying a similar curiosity.

The Black-throated Blue Warbler nests to the north of the lower Susquehanna valley, which it transits as a common spring and fall migrant.  On their wintering grounds, they have a thing for warm weather and the better part of a P.B. & J. sandwich.
Throughout the Susquehanna watershed, the Ovenbird is a common ground-nesting species in deciduous forests with moderately vegetated understories.  The birds seen today may have been a family group that has not yet begun the journey south.

When they depart the Susquehanna valley, these two warbler species will be southbound for wintering ranges that include Florida, many of the Caribbean Islands, Central America, and, for the Ovenbirds, northern South America.  Their flights occur at night.  During the breeding season and while migrating, both feed primarily on insects and other arthropods .  On the wintering grounds, they will consume some fruit.  It is during their time in the tropics that the Black-throated Blue Warbler sometimes visits feeding stations that offer grape jelly, much to the delight of bird enthusiasts.

Black-throated Blue Warblers and Ovenbirds commonly winter on the Florida peninsula and in the Bahamas.  With the major tropical cyclone Hurricane Dorian presently ripping through the region, these birds are better off taking their time getting there.  There’s no need to hurry.  The longer they and the other Neotropical migrants hang around, the more we get to enjoy them anyway.  So get out there to see them before they go—and remember to look up.

Category 4 Hurricane Dorian at 9:06 EDT on September 2, 2019.  If you’re headed that direction, there’s no need to hurry.  Note the cloud-free skies over much of the mainland.  (NOAA National Environmental Satellite, Data, and Information Service image)
A massive bird migration is indicated on Doppler radar in the clear skies over the eastern United States tonight (blue and green over most of the mainland).  In this loop of composite radar images from the southeastern states, note the relative absence of a flight over the Florida peninsula where the outer precipitation bands of Hurricane Dorian can be seen.  Note too that there appears to be a heavy concentration of birds flying in a southwest direction to cross the Gulf of Mexico, thus continuing their journey to Central or South America while avoiding the deadly hurricane and a much smaller tropical disturbance off the shores of Texas and Tamaulipas, Mexico.  (NOAA/National Weather Service image)

Spotted Lanternfly in the Lower Susquehanna River Watershed

Second Mountain Hawk Watch is located on a ridge top along the northern edge of the Fort Indiantown Gap Military Reservation and the southern edge of State Game Lands 211 in Lebanon County, Pennsylvania.  The valley on the north side of the ridge, also known as St. Anthony’s Wilderness, is drained to the Susquehanna by Stony Creek.  The valley to the south is drained toward the river by Indiantown Run, a tributary of Swatara Creek.

The hawk watch is able to operate at this prime location for observing the autumn migration of birds, butterflies, dragonflies, and bats through the courtesy of the Pennsylvania Game Commission and the Garrison Commander at Fort Indiantown Gap.  The Second Mountain Hawk Watch Association is a non-profit organization that staffs the count site daily throughout the season and reports data to the North American Hawk Watch Association (posted daily at hawkcount.org).

Today, Second Mountain Hawk Watch was populated by observers who enjoyed today’s break in the rainy weather with a visit to the lookout to see what birds might be on the move.  All were anxiously awaiting a big flight of Broad-winged Hawks, a forest-dwelling Neotropical species that often travels back to its wintering grounds in groups exceeding one hundred birds.  Each autumn, many inland hawk watches in the northeast experience at least one day in mid-September with a Broad-winged Hawk count exceeding 1,000 birds.  They are an early-season migrant and today’s southeast winds ahead of the remnants of Hurricane Florence (currently in the Carolinas) could push southwest-heading “Broad-wings” out of the Piedmont Province and into the Ridge and Valley Province for a pass by the Second Mountain lookout.

The flight turned out to be steady through the day with over three hundred Broad-winged Hawks sighted.  The largest group consisted of several dozen birds.  We would hope there are probably many more yet to come after the Florence rains pass through the northeast and out to sea by mid-week.  Also seen today were Bald Eagles, Ospreys, American Kestrels, and a migrating Red-headed Woodpecker.

Migrating Broad-winged Hawks circle on a thermal updraft above Second Mountain Hawk Watch to gain altitude before gliding away to the southwest.

Migrating insects included Monarch butterflies, and the three commonest species of migratory dragonflies: Wandering Glider, Black Saddlebags, and Common Green Darner.  The Common Green Darners swarmed the lookout by the dozens late in the afternoon and attracted a couple of American Kestrels, which had apparently set down from a day of migration.  American Kestrels and Broad-winged Hawks feed upon dragonflies and often migrate in tandem with them for at least a portion of their journey.

Still later, as the last of the Broad-winged Hawks descended from great heights and began passing by just above the trees looking for a place to settle down, a most unwelcome visitor arrived at the lookout.  It glided in from the St. Anthony’s Wilderness side of the ridge on showy crimson-red wings, then became nearly indiscernible from gray tree bark when it landed on a limb.  It was the dreaded and potentially invasive Spotted Lanternfly (Lycorma delicatula).  This large leafhopper is native to Asia and was first discovered in North America in the Oley Valley of eastern Berks County, Pennsylvania in 2014.  The larval stage is exceptionally damaging to cultivated grape and orchard crops.  It poses a threat to forest trees as well.  Despite efforts to contain the species through quarantine and other methods, it’s obviously spreading quickly.  Here on the Second Mountain lookout, we know that wind has a huge influence on the movement of birds and insects.  The east and southeast winds we’ve experienced for nearly a week may be carrying Spotted Lanternflies well out of their most recent range and into the forests of the Ridge and Valley Province.  We do know for certain that the Spotted Lanternfly has found its way into the Lower Susquehanna River Watershed.

This adult Spotted Lanternfly landed in a birch tree behind the observers at the Second Mountain Hawk Watch late this afternoon.  It was first recognized by its bright red wings as it glided from treetops on the north side of the lookout.

Winter Won’t Let Go…the Birds Don’t Care

It seems as though the birds have grown impatient for typical spring weather to arrive.  The increase in hours of daylight has signaled them that breeding time is here.  No further delays can be entertained.  They’ve got a schedule to keep.

Thursday, March 29:  Winds began blowing from the southwest, breaking a cold spell which had persisted since last week’s snowfall.  Birds were on the move ahead of an approaching rainy cold front.

Friday, March 30:  Temperatures reached 60 degrees at last.  Birds were again moving north through the day, despite rain showers and a change in wind direction—from the northwest and cooler following the passage of the front in the late morning.

Flocks of Double-crested Cormorants followed the Susquehanna River north in numerous V-shaped flocks during the recent several days.
There were Turkey Vultures by the hundreds on the way north.
And nearly as many Black Vultures too.

Saturday, March 31:  It was cooler, but birds were still on the wing headed north.

At sunrise, a migrating Northern Flicker stopped by at a suet feeder to refuel.

Osprey pairs have arrived at nest sites on the lower Susquehanna.

Sunday, April 1:  The morning was pleasant, but conditions became cooler and breezy in the afternoon.  Migratory and resident birds began feeding ahead of another storm.

A distant flock of fast-flying Bonaparte’s Gulls (Chroicocephalus philadelphia) moves expeditiously up the Susquehanna at Conewago Falls as winds begin to pick up during the late morning.  Are they hurrying to get north of the path of the forthcoming weather system?
A Mourning Dove (Zenaida macroura) feeds in anticipation of a snowy night ahead.
A male Downy Woodpecker devours a late-afternoon meal.
This Tufted Titmouse (Baeolophus bicolor), a cavity-nesting species, is distracted by a potential new home.
Dark-eyed Juncos winter in the lower Susquehanna valley.  During the month of April, they will begin departing for their breeding grounds, some nesting in the mountains just to our north.
Tufted Titmouse…still house hunting.
A male American Goldfinch is progressing through molt into a showy breeding (alternate) plumage.
A male House Finch takes a break from its melodious song to feed before the arrival of our next spring snow.  His mate is already incubating eggs in a nest not far away.
Northern Cardinals (Cardinalis cardinalis) feed through the late afternoon, often as the last birds out-and-about before darkness.  This male remains close to his mate as she forages beneath nearby shrubs.

Monday, April 2: Snow fell again, overnight and through the morning—a couple of inches.  Most of the snow had melted away by late afternoon.

Horned Larks are plentiful in large open bare-soil (tilled) farmlands in winter, particularly near fresh manure.  Their sandy-tan coloration hides them well, and they are seldom noticed unless spotted at roadside following snow storms.  Horned Larks are migratory ground-nesting birds found in many sparsely vegetated habitats including tundra, parched fields and prairies, beaches, and even airports.  There is a breeding population in the lower Susquehanna valley which may be increasingly attracted to favorable nesting habitat created in some no-till fields, possibly using a window of opportunity between the demise of cold-season cover crops and the ascendency of the warm-season crops to complete a brood cycle.  Comparing the site selection and success rates of nesting Horned Larks under various crop management methods, including reactions to herbicide use, could be an enlightening study project for inquisitive minds. (Hint-Hint)
The dainty Chipping Sparrow has arrived. This species commonly nests in small trees, often in suburban gardens.

A Century of Extinction

Many are wont to say that they have no capacity for scientific pursuits, and having no capacity, they consequently have no love for them.  I do not believe, that as a general thing, a love for science is necessarily innate in any man.  It is the subject of cultivation and is therefore acquired.  There are doubtless many, whose love for these and kindred pursuits is hereditary, through the mental biases and preoccupations of their progenitors, but in the masses of mankind it is quite otherwise.  In this consists its redeeming qualities, for I do not think the truly scientific mind can either be an idle, a disorderly, or a very wicked one.  There may be scientific men, who, forgetful of its teachings, are imperious and ambitious–who may have foregone their fealty to their country and their God, but as a general thing they are humble, social and law-abiding.  If, therefore, there is a human being who desires to break off from old and evil associations, and form new and more virtuous ones, I would advise him to turn his attention to some scientific specialty, for the cultivation of a new affection, if there are no other and higher influences more accessible.  In this pursuit he will, in time, be enabled to supplant the old and heartfelt affection.  The occupation of his mind in the pursuit of scientific lore will wean him from vicious, trivial, and unmanly pursuits, and point out to him a way that is pleasant and instructive to walk in, which will ultimately lead to moral and intellectual usefulness.  I wish I was accessible to them, and possessed the ability to impress this truth with sufficient emphasis upon the minds of the rising generation.  This fact, that in all moral reformations, a love for the opposite of any besetting evil must be cultivated, before that evil can be surely eradicated, has been too much overlooked and too little valued in moral ethics.  But true progress in this direction implies that, under all circumstances, men should “act in freedom according to reason.”

                                                                            -Simon S. Rathvon

 

In the cellar of the North Museum on the campus of Franklin and Marshall College in Lancaster, Pennsylvania, is an assemblage of natural history specimens of great antiquity.  The core of the collection has its origins in the endeavors of a group of mid-to-late nineteenth-century naturalists whose diligence provided a most thorough study of the plants and animals found within what was at the time America’s most productive farming county.

The members of the Linnaean Society of Lancaster City and County shared a passion for collecting, identifying, classifying, and documenting the flora and fauna of the region.  Some members were formally educated and earned a living in the field of science, but the majority were in the process of self-education and balanced their natural history occupation with an unrelated means to provide financially for their families.  The latter benefited greatly from their associations with the former, gaining expertise and knowledge while participating in the functions of the group.

On February 24, 1866, Simon S. Rathvon, the society’s Treasurer, read an essay in commemoration of the group’s fourth anniversary.  Rathvon earned a living as a tailor, first in Marietta, a thriving river town at the time, then in Lancaster City.  In 1840, Rathvon was elected into the Marietta Natural History Lyceum where, as a collections curator, he became associated with principals Judge John J. Libhart, an amateur ornithologist, and Samuel S. Haldeman, a geologist and soon to be widely-known malacologist.  Haldeman, in 1842, upon noticing the new member’s interest in beetles and other insects, provided books, guidance, and inspiration, thus intensifying Rathvon’s study of entomology.  Rathvon’s steadfast dedication eventually led to his numerous achievements in the field which included the publication of over 30 papers, many on the topic of agricultural entomology.  Rathvon’s scientific understanding of insect identification and taxonomy was a foundation for his practical entomology, which moved beyond mere insect collection to focus upon the study of the life histories of insects, particularly the good and bad things they do.  He then applied that knowledge to help growers solve pest problems, often stressing the value of beneficial species for maintaining a balance in nature.  From 1869 through 1884, Rathvon edited and published Lancaster Farmer, a monthly (quarterly from 1874) agricultural journal in which he educated patrons with his articles on “economic entomology”.  Rathvon continued earning a living in the tailor business, seemingly frustrated that his financially prudent advice on insect control in Lancaster Farmer failed to entice more would-be readers to part with the one dollar annual subscription fee.  For many years, Rathvon crafted articles for local newspapers and wrote reports for the United States Department of Agriculture.  In recognition of his achievements, Simon Rathvon received an honorary Ph.D. from Franklin and Marshall College in 1878.

In Rathvon’s anniversary essay, he details the origins of the Linnaean Society as a natural science committee within the “Lancaster Historical, Mechanical, and Horticultural Society” founded in 1853.  The members of the committee, not finding sufficient support within the parent organization for their desired mission, “the cultivation and investigation of the natural history of Lancaster County…”, sought to form an independent natural history society.  In February of 1862, the “Linnaean Society of Lancaster City and County” was founded to fulfill these ambitions.

Above all else, the written works by the members of the Linnaean Society and their predecessors have provided us with detailed accounts of the plants and animals found in Lancaster County, and in the lower Susquehanna River valley, using scientific binomial nomenclature, a genus and species name, as opposed to the variable folk and common names which, when used exclusively, often confuse or mislead readers.  Consider the number of common names a species could have if just one was assigned by each of the languages of the world.  Binomial nomenclature assigns one designation, a genus name and species name, in Latin, to each life-form (such as Homo sapiens for Humans), and it is adopted universally.

Rathvon would say of the naming of the Linnaean Society:

“…the name which the Society has adopted is in honorable commemoration of LINNAEUS, the great Swedish naturalist—one who may be justly regarded as a father in Natural Science.  To him belongs the honor of having first promulgated the “binomial system of nomenclature,” a system that has done more to simplify the study of natural science than any light that has been brought to the subject by any man in any age.”

Carl Linnaeus lived from 1707 to 1778, and published his first edition of Systema Naturae in 1735.

The names of a number of the members and corresponding members on the Linnaean Society of Lancaster City and County’s rolls remain familiar.  John P. McCaskey (educator) served as Corresponding Secretary.  Doctor Abram P. Garber was a prominent Lancaster botanist and society member.  Professor Samuel S. Haldeman (naturalist, geologist, and philologist), Professor J. L. LeConte (entomologist), Judge John J. Libhart, Professor Asa Gray (botanist), and the foremost legal egalitarian in the United States House of Representatives, the Honorable Thaddeus Stevens, were  listed among the roster of corresponding members.

By the end of its fourth year, Rathvon enumerated the specimens in the collections of the society to exceed 32,000.  These included all the species of mosses and plants known in the county, 200 bird specimens, an enormous insect collection with nearly 12,000 Coleoptera (Beetles), and more than 1,400 mollusk shells.  The work of the society had already provided a thorough baseline of the flora and fauna of the lower Susquehanna River valley and Lancaster County.

Rathvon would continue as Treasurer and primary curator through the group’s first twenty-five years, their most active.  By 1887, their library contained over 1,000 volumes, they possessed over 40,000 specimens, and more than 600 scientific papers had been read at their meetings.

Many of the society’s specimens were moved to the custody of Franklin and Marshall College following the group’s dissolution.  In 1953, the collection found a home on the F&M campus at the newly constructed North Museum, named for benefactor Hugh M. North, where many of the specimens, particularly the birds, are on prominent display.

Among the mounted specimens in the North Museum collection is a Heath Hen, once a numerous coastal plain bird which was also of limited abundance in the Piedmont Province areas of southeast Pennsylvania prior to its rapid decline during the first half of the nineteenth century.  In southern Lancaster County, the burned grasslands of the serpentine barrens in Fulton Township may have provided suitable Heath Hen habitat prior to the bird’s demise.  Curiously, Judge John J. Libhart did not note the Heath Hen in his enumeration of the birds of Lancaster County in either 1844 or 1869, indicating it was seriously imperiled or may have already been extirpated.

The Heath Hen (Tympanuchus cupido cupido) became extinct in 1932.  While the collection of this particular specimen had little significant impact on the population of this subspecies as a whole, prolonged hunting pressure was largely responsible for decimating the numbers of Heath Hens on the mainland of the Atlantic Coastal Plain.   According to the museum tag, this specimen was “probably taken in southern Lancaster County prior to 1850”, and was part of the collection belonging to the Linnaean Society of Lancaster City and County.  It is among hundreds of bird specimens on display in antique wood and glass cabinets in the North Museum.

The Heath Hen was extirpated from its entire Atlantic Coastal Plain mainland range by the mid-1860s.  The last remaining population was restricted to Martha’s Vineyard where, for the first time, a conservation effort was initiated to try to save a species.  After some promising rebounds, the Heath Hen’s recovery failed for a variety of reasons including: the population’s isolation on an island, severe winter storms, feral cat predation, and a flawed understanding of methods for conducting mosaic burns to maintain the bird’s scrub habitat and prevent large catastrophic fires.  A large fire in 1906 reduced the island population to just 80 birds, then there was a strong rebound to an estimated 2,000 birds (800 counted) by April, 1916.  One month later, a fire burned twenty percent of Martha’s Vineyard, striking while females were on the nest, and leaving mostly males as survivors.  A downward spiral in numbers followed for another decade.  Finally, from 1929 until his death in 1932, “Booming Ben”, the last Heath Hen, searched the island every spring for a mate that wasn’t there.

Based on life history and the morphology of specimens, the Heath Hen has long been considered to be a subspecies of the Greater Prairie Chicken (Tympanuchus cupido pinnatus), a bird of the tallgrass prairies.  However, for more than a decade now, modern DNA analysis has kept taxonomists busy reclassifying and reworking the “tree of life”.  For certain species, genetic discoveries often disqualify the long-trusted practice of determining a binomial name based on the visual appearance of specimens.  Molecular study is making Linnaean classification more scientific, and is gradually untangling a web of names that man has been weaving for 200 years, often with scant evidence, in an effort to better understand the world around him.  In the case of the Heath Hen, DNA research has thus far failed to conclusively determine its relationship to other species of prairie chickens.  The lack of a sufficient pool of genetic material, particularly from mainland Heath Hens, reduces the ability of researchers to draw conclusions on this group of birds.  There remains the possibility that the Heath Hen was genetically distinct from the Greater Prairie Chickens of the mid-western United States.  This would be bad news for organizations studying the possibility of introducing the latter into the former’s historic range as a restoration program.

The Carolina Parakeet (Conuropsis carolinensis) specimen on display at the North Museum was collected by John C. Jenkins in Nanchez, Mississippi in 1835.  The specimen was remounted by conservator H. Justin Roddy.

The last Carolina Parakeet (the only parrot species native to the eastern United States) died in captivity in the Cincinnati Zoo on February 21, 1918, one hundred years ago this past week.  It was a species inhabiting primarily the lowland forests of the southeastern United States

In Lancaster County, Judge John J. Libhart wrote of the species in 1869, “…Carolina Parrot, Accidental; a flock seen near Manheim by Mr. G. W. Hensel.”  Libhart did not mention the species in his earlier ornithological writings (1844).  Therefore, the Hensel sighting probably occurred sometime between 1844 and 1869.  The fate of a specimen reported to have been collected in the town of Willow Street sometime during the nineteenth century is unknown, the written details lack the date of its origin and other particulars that may clarify the authenticity of the sighting.

McKinley (1979) researched numerous historical sight records of Carolina Parakeets, but found no specimen from Lancaster County, or from Pennsylvania, New Jersey, Delaware, the District of Columbia, or Maryland to substantiate any of the reports in the Mid-Atlantic states.  In the days prior to high-speed photography, verification and documentation of the presence of an animal species relied on what seems today to be a brutal and excessive method of nature study, killing.  Lacking a specimen, the historical status of Carolina Parakeets in Pennsylvania, an area often considered to be within the bird’s former range, may be considered by many authorities to be hypothetical.

The Passenger Pigeon (Ectopistes migratorius) was abundant in the lower Susquehanna River valley through the early nineteenth century.  Specimens in the North Museum collection include colorful males in breeding plumage.  Several are from the original Linnaean Society of Lancaster City and County collection.

The Passenger Pigeon, too, has been extinct for more than a century.  In Lancaster County, Judge John J. Libhart listed the Passenger Pigeon by the common name “Wild Pigeon” and wrote of the species in 1869, “Migratory; spring and autumn; feeds on grain, oak and beach, mostly on berries; stragglers sometimes remain and breed in the county.”   There are numerous accounts of their precipitous decline both locally and throughout their former range, each illustrating the tragic loss of another portion of the North American natural legacy.

The North Museum specimen label describes the precipitous decline of the Passenger Pigeon in the lower Susquehanna River valley.

Martha, the last surviving Passenger Pigeon, died on September 1, 1914, in the Cincinnati Zoo.  Ironically, the last Carolina Parakeet would die in the same enclosure just three-and-one-half years later.  In the wild, the final three records of Passenger Pigeons were all of birds that were shot for taxidermy mounts in 1900, 1901, and 1902—an embarrassing human legacy.

By the early twentieth century, concerned citizens were beginning to realize the danger posed to many species of flora and fauna by man’s activities.  In the eastern United States, the vast forests had been logged, the wetlands drained, and the streams and rivers dammed.  Nearly all of the landscape had been altered in some way.  Animals were harvested with little concern for the sustenance of their populations.  Nearly unnoticed, the seemingly endless abundance and diversity of wildlife found in the early days of European colonization had dwindled critically.

In 1844, Judge John J. Libhart noted the “Log-Cock” among the birds found in Lancaster County.  Fortunately, he included the scientific name “Picus pileatus”, the binomial nomenclature then recognized for the Pileated Woodpecker (specimens to right) among taxonomists.  A record of “Log-Cock” could confuse researchers, leaving them to guess whether Libhart was referring to a woodpecker, a woodcock, a grouse, or any number of other birds including the long-extinct(?) Ivory-billed Woodpecker (Campephilus principalis).  Of the Pileated Woodpecker (Dryocopus pileatus today), Libhart wrote in 1869, “…now become rare and is only met with in old and extensive woods; breeds in the county.”  The Ivory-billed Woodpecker (specimen to left), a species of vast forests of large timber, living and dead, was restricted to the southeastern United States and Cuba.  Logging following the American Civil War and, to a lesser degree, shooting impacted both species detrimentally.  The Pileated Woodpecker recovered, the larger Ivory-billed Woodpecker, which has never been documented in the northeastern United States, has not.  These specimens are in the North Museum collection.

The movement to conserve and protect threatened species from relentless persecution owes its start to the Linnaean taxonomists, the specimen collectors who gave uniformly recognizable names to nearly all of North America’s plants and animals.  Significant too were John James Audubon and many others who used specimens as models to create accurate artwork which allowed scientists and citizens alike to learn to identify and name the living things they were seeing and, as time went by, not seeing.

Binomial nomenclature enabled the new conservationists to communicate accurately, reducing misunderstandings resulting from the use of many different names for one species or a shared name for multiple species.  Discussions on the status of Columba migratorius (the binomial name for Passenger Pigeon in the nineteenth century) could occur without using the confusing local names for the Passenger Pigeon such as Wood Pigeon or, here in Pennsylvania, Wild Pigeon, a term which could describe any number of free-ranging pigeon or dove species.  A binomial name, genus and species, makes the identity of a particular plant or animal, for lack of a more fitting term, specific.

Appreciation for the work completed by taxonomists who killed thousands of animals so each could be classified and assigned a name particular to its lineage is what finally motivated some to seek a cessation of the unchecked catastrophic killing of living things.  It’s the paradox of late nineteenth-century conservation.  The combined realization that a species is unique among other life-forms and that continuing to kill it for specimens, “style”, “sport”, or just an adrenaline thrill could eliminate it forever became an intolerable revelation.  The blood would be on the hands of an audacious mankind, and it was unthinkable.  Something had to be done.  Unfortunately for the Passenger Pigeon, the Carolina Parakeet, and the Heath Hen, help came too late.

SOURCES

Greenburg, Joel.  2014.  A Feathered River Across the Sky: The Passenger Pigeon’s Flight to Extinction.  Bloomsbury Publishing.  New York. 

Libhart, John J.  1844.  “Birds of Lancaster County”.  I. Daniel Rupp’s History of Lancaster County.  Gilbert Hills.  Lancaster, PA.

Libhart, John J.  1869.  “Ornithology”.  J. I. Mombert’s An Authentic History of Lancaster County.  J. E. Barr and Company.  Lancaster, PA.

McKinley, Daniel.  1979.  “History of the Carolina Parakeet in Pennsylvania, New Jersey, Delaware, Maryland, and the District of Columbia”.  Maryland Birdlife.  35(1):1-10.

Palkovacs, Eric P.; Oppenheimer, Adam J.; Gladyshev, Eugene; Toepfer, John E.; Amato, George; Chase, Thomas; Caccone, Adalgesia.  2004.  “Genetic Evaluation of a Proposed Introduction: The Case of the Greater Prairie Chicken and the Extinct Heath Hen”.  Molecular Ecology.  13(7):1759-1769.

Rathvon, S. S.  1866.  An Essay on the Origin of the Linnaean Society of Lancaster City and County, Its Objects and Progress.  Pearsol and Geist.  Lancaster, Pennsylvania.

Wheeler, Alfred G., Jr. and Miller, Gary L.  2006.  “Simon Snyder Rathvon: Popularizer of Agricultural Entomology in Mid-19th Century America”.  American Entomologist.  52(1):36-47.

Winpenny, Thomas R.  1990.  “The Triumphs and Anguish of a Self-Made Man: 19th Century Naturalist S. S. Rathvon”.  Pennsylvania History.  57(2):136-149.

Loading Up For Winter

A very light fog lifted quickly at sunrise.  Afterward, there was a minor movement of migrants: forty-nine Ring-billed Gulls, a few Herring Gulls, a Red-shouldered Hawk following the river to the southeast, and small flocks totaling nine Cedar Waxwings and twenty-eight Red-winged Blackbirds.

A Belted Kingfisher in the morning fog.
A Ring-billed Gull calls as active migrants pass overhead on their way downriver.
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In the Riparian Woodland, small mixed flocks of winter resident and year-round resident birds were actively feeding.  They must build and maintain a layer of body fat to survive blustery cold nights and the possible lack of access to food during snowstorms.  There’s no time to waste; nasty weather could bring fatal hardship to these birds soon.

A Carolina Chickadee (Poecile carolinensis) feeds on the seeds of an Eastern Sycamore (Platanus occidentalis), also known as American Sycamore.  Chickadees are generalist feeders, eating invertebrates and suet at feeding stations in addition to the seeds of many plants.  Carolina Chickadees are year-round residents at Conewago Falls.
A fast-moving Golden-crowned Kinglet zips from limb to limb to grab tiny insects and other invertebrates.  During the winter, these petite birds will carefully probe the bark and crevices of trees to glean enough food to survive.  Golden-crowned Kinglets are winter residents at Conewago Falls.  In spring, they will depart to nest in coniferous forests.
A Downy Woodpecker (Picoides pubescens) searches an infected tree for insects.  They are year-round residents.
Carolina Wrens (Thryothorus ludovicianus) are considered year-round residents at Conewago Falls, though they may withdraw to the south during severe winters.  Carolina Wrens sing year-round.  Today, their loud melody echoed through the Riparian Woodland all morning.
The tiny bob-tailed Winter Wren is an elusive ground-dwelling winter resident at the falls.  You may hear their scolding chatter from rocky areas and tree logs where they climb around mouse-like in search of small invertebrates.  Their song is a fast jumble of dainty musical trills that can sometimes be heard echoing through the Riparian Woodland in winter.  In spring, they’ll depart to nest in damp coniferous forests.

Anthropoavians

Temperatures plummeted to well below freezing during the past two nights, but there was little sign of it in Conewago Falls this morning.  The fast current in the rapids and swirling waters in flooded Pothole Rocks did not freeze.  Ice coated the standing water in potholes only in those rocks lacking a favorable orientation to the sun for collecting solar heat during the day to conduct into the water during the cold nights.

On the shoreline, the cold snap has left its mark.  Ice covers the still waters of the wetlands.  Frost on exposed vegetation lasted until nearly noontime in shady areas.  Insect activity is now grounded and out of sight.  The leaves of the trees tumble and fall to cover the evidence of a lively summer.

The nocturnal bird flight is narrowing down to just a few species.  White-throated Sparrows, a Swamp Sparrow (Melospiza georgiana), and Song Sparrows are still on the move.  Though their numbers are not included in the migration count, hundreds of the latter are along the shoreline and in edge habitat around the falls right now.  Song Sparrows are present year-round, migrate at night, and are not seen far from cover in daylight, so migratory movements are difficult to detect.  It is certain that many, if not all of the Song Sparrows here today have migrated and arrived here recently.  The breeding population from spring and summer has probably moved further south.  And many of the birds here now may remain for the winter.  Defining the moment of this dynamic, yet discrete, population change and logging it in a count would certainly require different methods.

Song Sparrows are now abundant in the brushy edges of fields and woodlands.  They may even break into song on sunny days.

Diurnal migration was foiled today by winds from southerly directions and moderating temperatures.  The only highlight was an American Robin flight that extended into the morning for a couple of hours after daybreak and totaled over 800 birds.  This flight was peppered with an occasional flock of blackbirds.  Then too, there were the villains.

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They’re dastardly, devious, selfish, opportunistic, and abundant.  Today, they were the most numerous diurnal migrant.  Their numbers made this one of the biggest migration days of the season, but they are not recorded on the count sheet.  It’s no landmark day.  They excite no one.  For the most part, they are not recognized as migrants because of their nearly complete occupation of North America south of the taiga.  If people build on it or alter it, these birds will be there.  They’re everywhere people are.  If the rotten attributes of man were wrapped up into one bird, an “anthropoavian”, this would be it.

Meet the European Starling (Sturnus vulgaris).  Introduced into North America in 1890, the species has spread across the entire continent.  It nests in cavities in buildings and in trees.  Starlings are aggressive, particularly when nesting, and have had detrimental impacts on the populations of native cavity nesting birds, particularly Red-headed Woodpeckers, Purple Martins (Progne subis), and Eastern Bluebirds.  They commonly terrorize these and other native species to evict them from their nest sites.  European Starlings are one of the earlier of the scores of introduced plants and animals we have come to call invasive species.

Noisy flocks of European Starlings are right at home on man-made structures in city and country.

Today, thousands of European Starlings were on the move, working their way down the river shoreline and raiding berries from the vines and trees of the Riparian Woodlands.  My estimate is between three and five thousand migrated through during the morning.  But don’t worry, thousands more will be around for the winter.

European Starlings mob a Sharp-shinned Hawk from above, a common behavior.
An Eastern Bluebird feeds on the few berries left untouched by passing European Starlings.

Feathered Fallout

The NOAA National Weather Service radar images from last evening provided an indication that there may be a good fallout of birds at daybreak in the lower Susquehanna valley.  The moon was bright, nearly full, and there was a gentle breeze from the north to move the nocturnal migrants along.  The conditions were ideal.

Rising from daytime roosts in New York and Pennsylvania, then streaming south in moonlit skies, migrating birds are recorded as echoes on this post-sunset composite NEXRAD loop from last evening.  (NOAA/National Weather Service image)

The Riparian Woodlands at Conewago Falls were alive with migrants this morning.  American Robins and White-throated Sparrows were joined by new arrivals for the season: Brown Creeper (Certhia americana), Ruby-crowned Kinglets (Regulus calendula), Golden-crowned Kinglets (Regulus satrapa), Dark-eyed Junco (Junco hyemalis), and Yellow-rumped Warbler (Setophaga coronata).  These are the perching birds one would expect to have comprised the overnight flight.  While the individuals that will remain may not yet be among them, these are the species we will see wintering in the Mid-Atlantic states.  No trip to the tropics for these hardy passerines.

American Robins continued migratory flight into the first hour of daylight this morning.  Their calls are commonly heard at night as migrating individuals pass overhead.
White-throated Sparrows are nocturnal migrants, and are a familiar find on woodland edges and at suburban feeding stations through the winter.
Dark-eyed Juncos, also nocturnal migrants, are common winter residents in the Lower Susquehanna River Watershed, frequently visiting bird feeders.
Heavy rain earlier this week in the Susquehanna River drainage basin has flooded most of the Pothole Rocks; the rapids of Conewago Falls have returned.
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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), Herring Gull (Larus argentatus), 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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State of Confusion

The humid rainy remains of Hurricane Nate have long since passed by Pennsylvania, yet mild wet weather lingers to confuse one’s sense of the seasons.  This gloomy misty day was less than spectacular for watching migrating birds and insects, but some did pass by.  Many resident animals of the falls are availing themselves of the opportunity to continue active behavior before the cold winds of autumn and winter force a change of lifestyle.

Warm drizzle at daybreak prompted several Northern Spring Peepers (Pseudacris crucifer crucifer) to begin calling from the wetlands in the Riparian Woodlands of Conewago Falls.  An enormous chorus of these calls normally begins with the first warm rains of early spring to usher in this tiny frog’s mating season.  Today, it was just a few “peeps” among anxious friends.

The tiny Northern Spring Peeper is recognized by the dark “X” across its back.  Soon, shelter must be found among loose bark and fallen logs to commence hibernation.  Emergence, often prompted by warm spring rains, will quickly be followed by a growing chorus of breeding calls as sometimes hundreds of these frogs assemble in vernal pools where mating will then occur.

Any additional river flow that resulted from the rains of the previous week is scarcely noticeable among the Pothole Rocks.  The water level remains low, the water column is fairly clear, and the water temperatures are in the 60s Fahrenheit.

It’s no real surprise then to see aquatic turtles climbing onto the boulders in the falls to enjoy a little warmth, if not from the sun, then from the stored heat in the rocks.  As usual, they’re quick to slide into the depths soon after sensing someone approaching or moving nearby.  Seldom found anywhere but on the river, these skilled divers are Common Map Turtles (Graptemys geographica), also known as Northern Map Turtles.  Their paddle-like feet are well adapted to swimming in strong current.  They are benthic feeders, feasting upon a wide variety of invertebrates found among the stone and substrate of the river bottom.

Adult Common Map Turtles hibernate communally on the river bottom in a location protected from ice scour and turbulent flow, often using boulders, logs, or other structures as shelter from strong current.  The oxygenation of waters tumbling through Conewago Falls may be critical to the survival of the turtles overwintering downstream.  Dissolved oxygen in the water is absorbed by the nearly inactive turtles as they remain submerged at their hideout through the winter.  Though Common Map Turtles, particularly males, may occasionally move about in their hibernation location, they are not seen coming to the surface to breathe.

The Common Map Turtles in the Susquehanna River basin are a population disconnected from that found in the main range of the species in the Great Lakes and upper Mississippi basin.  Another isolated population exists in the Delaware River.

Common Map Turtles, including this recently hatched young seen in August, are often observed climbing onto rocks in the river.
Note the oversize swimming fin adaptations of the feet on this adult Common Map Turtle found among the Pothole Rocks in Conewago Falls.  Young and adults are capable of navigating some strong current to feed and escape danger.
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SOURCES

Committee on the Status of Endangered Wildlife in Canada.  2002.  Status Report of the Northern Map Turtle.  Canadian Wildlife Service.  Ottawa, Ontario.

Summer Breeze

A moderate breeze from the south placed a headwind into the face of migrants trying to wing their way to winter quarters.  The urge to reach their destination overwhelmed any inclination a bird or insect may have had to stay put and try again another day.

Blue Jays were joined by increasing numbers of American Robins crossing the river in small groups to continue their migratory voyages.  Killdeer (Charadrius vociferous) and a handful of sandpipers headed down the river route.  Other migrants today included a Cooper’s Hawk (Accipiter cooperii), Eastern Bluebirds (Sialia sialis), and a few Common Mergansers (Mergus merganser), House Finches (Haemorhous mexicanus), and Common Grackles (Quiscalus quiscula).

The afternoon belonged to the insects.  The warm wind blew scores of Monarchs toward the north as they persistently flapped on a southwest heading.  Many may have actually lost ground today.  Painted Lady (Vanessa cardui) and Cloudless Sulphur butterflies were observed battling their way south as well.  All three of the common migrating dragonflies were seen: Common Green Darner (Anax junius), Wandering Glider (Pantala flavescens), and Black Saddlebags (Tramea lacerata).

The warm weather and summer breeze are expected to continue as the rain and wind from Hurricane Nate, today striking coastal Alabama and Mississippi, progresses toward the Susquehanna River watershed during the coming forty-eight hours.

This Great Blue Heron was joined by numerous other fishermen and a good number of sightseers in the falls today.
A colorful young Northern Water Snake (Nerodia sipedon) takes advantage of the sun-heated surface of a Pothole Rock to remain nimble and active.  Cooler weather will soon compel this and other reptiles to find shelter for winter hibernation.
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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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Blue Jay Way

The Neotropical birds that raised their young in Canada and in the northern United States have now logged many miles on their journey to warmer climates for the coming winter.  As their density decreases among the masses of migrating birds, a shift to species with a tolerance for the cooler winter weather of the temperate regions will be evident.

Though it is unusually warm for this late in September, the movement of diurnal migrants continues.  This morning at Conewago Falls, five Broad-winged Hawks (Buteo platypterus) lifted from the forested hills to the east, then crossed the river to continue a excursion to the southwest which will eventually lead them and thousands of others that passed through Pennsylvania this week to wintering habitat in South America.  Broad-winged Hawks often gather in large migrating groups which swarm in the rising air of thermal updrafts, then, after gaining substantial altitude, glide away to continue their trip.  These ever-growing assemblages from all over eastern North America funnel into coastal Texas where they make a turn to south around the Gulf of Mexico, then continue on toward the tropics.  In the coming weeks, a migration count at Corpus Christi in Texas could tally 100,000 or more Broad-winged Hawks in a single day as a large portion of the continental population passes by.  You can track their movement and that of other diurnal raptors as recorded at sites located all over North America by visiting hawkcount.org on the internet.  Check it out.  You’ll be glad you did.

Nearly all of the other migrants seen today have a much shorter flight ahead of them.  Red-bellied Woodpeckers (Melanerpes carolinus), Red-headed Woodpeckers (Melanerpes erythrocephalus), and Northern Flickers (Colaptes auratus) were on the move.  Migrating American Robins (Turdus migratorius) crossed the river early in the day, possibly leftovers from an overnight flight of this primarily nocturnal migrant.  The season’s first Great Black-backed Gulls (Larus marinus) arrived.  American Goldfinches are easily detected by their calls as they pass overhead.  Look carefully at the goldfinches visiting your feeder, the birds of summer are probably gone and are being replaced by migrants currently passing through.

By far, the most conspicuous migrant today was the Blue Jay.  Hundreds were seen as they filtered out of the hardwood forests of the diabase ridge to cautiously cross the river and continue to the southwest.  Groups of five to fifty birds would noisily congregate in trees along the river’s edge, then begin flying across the falls.  Many wary jays abandoned their small crossing parties and turned back.  Soon, they would try the trip again in a larger flock.

Sensing that they are being watched, Blue Jays are hesitant to fly across the narrow Susquehanna at Conewago Falls without first assembling into a flock.  The local constabulary often penalizes those who freelance and do not move in orderly groups.

A look at this morning’s count reveals few Neotropical migrants.  With the exception of the Broad-winged Hawks and warblers, the migratory species seen today will winter in a sub-tropical temperate climate, primarily in the southern United States, but often as far north as the lower Susquehanna River valley.  The individual birds observed today will mostly continue to a winter home a bit further south.  Those that will winter in the area of Conewago Falls will arrive in October and later.

The Great Blue Heron (Ardea herodius) can be found year-round at Conewago Falls, provided there is open water and adequate food.  Migrants from breeding colonies to the north will soon supplement the local population.
The Double-crested Cormorant (Phalacrocorax auritus) is a summer resident at Conewago Falls.  Migration of the local population and of those from further north will soon begin.  All will be gone by the time ice forms on the river.  Cormorants are often seen drying their feathers in sunlight following a series of feeding dives.

The long-distance migrating insect so beloved among butterfly enthusiasts shows signs of improving numbers.  Today, more than two dozen Monarchs were seen crossing the falls and slowly flapping and gliding their way to Mexico.

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