Back in late May of 1983, four members of the Lancaster County Bird Club—Russ Markert, Harold Morrrin, Steve Santner, and your editor—embarked on an energetic trip to find, observe, and photograph birds in the Lower Rio Grande Valley of Texas. What follows is a daily account of that two-week-long expedition. Notes logged by Markert some four decades ago are quoted in italics. The images are scans of 35 mm color slide photographs taken along the way by your editor.
DAY FIVE—May 25, 1983
Bentsen State Park, Texas
Went to bed last nite about 11:30. Did not set the alarm. Very hot — Awoke at 7:30 A.M. We circled the campground and then drove to the river trail. We walked to the river, getting more lifers for Larry — Couch’s Kingbird, Olive Sparrow, and Groove-billed Ani. The Couch’s Kingbird is my first lifer of the trip. The Olive Sparrow has the same cadence as the Tennessee Warbler. We then checked the resaca and found a Least Bittern.
While checking out the cattails at the resaca, we failed to catch a glimpse of a Coues’ Rice Rat (Oryzomys couesi), a semi-aquatic mammal that lives only in the Rio Grande Valley and areas south into Central America. Instead we found an Eastern Fox Squirrel (Sciurus niger), a giant compared to the gray squirrels in Pennsylvania. Things really are bigger in Texas.
Back to our camp site for lunch, after paying for our stay at the office. P.M. — Put out corn and sunflower seeds and loafed all P.M. trying to get pictures. Larry had a lot of luck. I did not do so good.
Plain Chachalacas, White-winged Doves, White-tipped Doves, Great-tailed Grackles, and a Bronzed Cowbird stopped by to sample the seed offerings. The chachalacas and grackles created quite a racket. It’s a good thing we didn’t have any neighbors close by!
In nearby areas of the campground there were many species—Black-bellied Whistling Duck, Anhinga, Great Egret, Common Gallinule, Turkey Vulture, Yellow-billed Cuckoo, Golden-fronted Woodpecker, Ladder-backed Woodpecker, Eastern Kingbird, Brown-crested Flycatcher, Curve-billed Thrasher, Long-billed Thrasher (Toxostoma longirostre), Altamira Oriole, and Northern Cardinal.
Rain is rare here — The rainy season produced no rain. Now a light rain is falling. The temperature dropped to 90° in the camper. One couple wanted to see anis. Larry picked one out 50 ft. from their campsite.
The rain cooled the air to make the evening tolerable, but we would pay for it tomorrow with an increase in the humidity.
We paid for another nite and at dusk went to the Elf Owl tree where eventually 4 young came out and tried their wings and crawled around. The two adults flew in and Larry was ecstatic taking pictures with his strobe light. We met some people. One couple never saw Eastern Bluebirds. I gave him my card. Another couple pinpointed the owl tree.
This evening was certainly highlighted by the emergence of the young Elf Owls (Micrathene whitneyi) from their nest cavity. But in addition, we again heard the sounds of some of the other nocturnal birds found in the park—Common Nighthawk, Common Pauraque, and Eastern Screech Owl.
Back in late May of 1983, four members of the Lancaster County Bird Club—Russ Markert, Harold Morrrin, Steve Santner, and your editor—embarked on an energetic trip to find, observe, and photograph birds in the Lower Rio Grande Valley of Texas. What follows is a daily account of that two-week-long expedition. Notes logged by Markert some four decades ago are quoted in italics. The images are scans of 35 mm color slide photographs taken along the way by your editor.
DAY TWO—May 22, 1983
Our goal today was to continue traveling and reach western Louisiana.
“We were on our way at 6:08. Stopped for a quick lunch in the camper and drove to Vinton, Louisiana, KOA. Lots of hard rain through Tennessee, Georgia, and Alabama.
As we crossed Mississippi and entered Louisiana, we left the rain and the Appalachians behind. Upon crossing the Mississippi River, we had arrived in the West Gulf Coastal Plain, the physiographic province that extends all the way south along the Texas coast to Mexico and includes the Lower Rio Grande Valley. West of Baton Rouge, we began seeing waders in the picturesque Bald Cypress swamps—Great Egrets, Green Herons (Butorides virescens), Little Blue Herons (Egretta caerulea), and Glossy Ibis (Plegadis falcinellus) were identified. A Pileated Woodpecker was observed as it flew above the roadside treetops.
The rains we endured earlier in the trip had left there mark in much of Louisiana and Texas. Flooding in agricultural fields was widespread and the flat landscape often appeared inundated as far as the eye could see. Along the highway near Vinton, we spotted the first two of the many southern specialties we would find on the trip, a Loggerhead Shrike (Lanius ludovicianus) and a Scissor-tailed Flycatcher (Tyrannus forficatus), both perched on utility wires and searching for a meal.
County Conservation District Tree Sales are underway throughout the Lower Susquehanna River Watershed. Now is the time to order for pickup in April. The prices are a bargain and the selection is fabulous. For species descriptions and more details, visit each tree sale web page (click the sale name highlighted in blue). And don’t forget to order bundles of evergreens for planting in mixed clumps and groves to provide winter shelter and summertime nesting sites for our local birds. They’re only $12.00 for a bundle of 10—can’t beat that deal!
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!
Other diurnal migrants are on the move as well…
Adding to the diversity of sightings, there are these diurnal raptors arriving in the area right now…
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.
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.
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.
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.
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.
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!
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.
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.
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.).
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!
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…
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
If you venture out, keep alert for the migrating birds of late winter and early spring.
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.
So just how many Green Frogs were there in that first photograph? Here’s the answer.
Happy Spring. For the benefit of everyone’s health, let’s hope that it’s a hot and humid one!
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.
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.
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.
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.
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.
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.
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.
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 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.
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.
Saturday, March 31: It was cooler, but birds were still on the wing headed north.
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.
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.
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 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 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, 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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Committee on the Status of Endangered Wildlife in Canada. 2002. Status Report of the Northern Map Turtle. Canadian Wildlife Service. Ottawa, Ontario.
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.
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.
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.
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 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.