Aeroecology

As the days shorten, birds begin to migrate long before cold weather sets in. I notice the first flush of migratory birds on our mountain sometime in mid-to-late August. But September and early October are the peak months here for bird migration.

Migrating snow geese near the Middle Creek Wildlife Management Area

Migrating snow geese near the Middle Creek Wildlife Management Area (Photo by the Chesapeake Bay Program on Flickr, Creative Commons license)

Now that they are on the move, birds enter the most dangerous phase of their lives, especially the immature birds that have never migrated before. They need safe places to land and forage, what ecologists call “habitat,” both water and land-based, depending on whether they are songbirds, raptors, waterfowl, or shorebirds.

Although researchers have made progress in studying how birds migrate, using the stars at night and landforms during the day, for instance, as well as what they eat and where they forage on land, they know less about what happens when the birds are airborne, especially when they encounter human activities.

A barn swallow in flight at the John Heinz National Wildlife Refuge

A barn swallow in flight at the John Heinz National Wildlife Refuge (Photo by Stan Lupo on Flickr, Creative Commons license)/

But in the last decade some ecologists maintain that since birds spend much of their lives in the air foraging, migrating and sometimes even mating, especially swallows and swifts, airspace should also be considered habitat, not only for birds, but bats and a wide variety of flying and even migrating insects such as butterflies and dragonflies.

While there was some discussion of airspace as habitat early in this century, it was a paper written in 2013 entitled “The Airspace is Habitat” by research ecologist Robert H. Diehl that launched the new study called “aeroecology.” Diehl, who studies migratory birds at the United States Geological Survey’s Northern Rocky Mountain Science Center, cited numerous definitions of habitat by several well-known ecologists. He summarized their contention “that occupancy, and perhaps resource use, are essential attributes of habitat,” and concluded that, ”airspace satisfies these criteria.”

Since Diehl’s ground-breaking but brief paper, numerous studies have been done on all aspects of airspace and its importance in the conservation of birds, bats and flying insects.

A wood thrush killed by striking a window

A wood thrush killed by striking a window (Photo by Bob on Flickr, Creative Commons license)

Studies show that up to a billion birds a year die in the United States when they fly into the windows of homes and office buildings, the most common and numerous obstacles in their airspace, according to the American Bird Conservancy. In addition, seven million fly into communication towers, although the latter number may decline since the Federal Communications Commission issued guidelines suggesting that tower operations switch from steady-burning to blinking lights that are less confusing to birds.

Then there are the wind turbines that kill many species of birds and bats that fly into the huge, rapidly-spinning blades. Unfortunately, many of those turbines have been built in the very places where birds and bats migrate, taking advantage of the wind. Here in our area, the leading Allegheny Ridge, a proven migratory highway, has dozens of wind turbines erected on it and more to come in the future. To its credit, the Pennsylvania Game Commission does not allow wind turbines on game lands but plenty of private and local government-owned landowners in Pennsylvania do.

Wildlife biologists collecting and recording migrating song birds killed by wind turbines

Wildlife biologists collecting and recording migrating song birds killed by wind turbines (Photo by kqedquest on Flickr, Creative Commons license)

Well-known birder Kenn Kaufman, in his new book A Season on the Wind, relates an on-going battle by his wife, Kimberly, executive director of the Black Swamp Bird Observatory, to keep wind turbines off Camp Perry, a military-owned property along Lake Erie in northwestern Ohio, which is next to Magee Marsh and other famous migrating bird stopovers. He writes that “wind turbines placed in the middle of essential stopover habitat” [such as the shores of Lake Erie] “are likely to kill disproportionate numbers of long-distance migrants, birds that are already pushing the limits of survival.” The same is true of Pennsylvania’s own shoreline of Lake Erie.

Furthermore, Kaufman insists, the numbers of birds and bats the wind industry claims are killed by the turbines are vast under estimates. While using the wind as a source of carbon-free electricity is necessary, it would be better for the birds and bats if the installations were smaller and local instead of massive and requiring powerlines, another threat to birds and bats, to transmit the energy.

Light pollution from human-related sources such as office towers in cities is especially dangerous to night-flying and/or migrating birds. How light pollution in general affects birds is still another branch of aeroecology research. According to one scientist, artificial light can be seen as far as 224 miles on the horizon. Artificial light at night may change the ability of night-migrating birds to orient and navigate, and also change the way birds communicate and avoid predation in addition to possibly screwing up their geomagnetic sense that helps them find their way.

Tribute in Lights 9-11-2017

Tribute in Lights 9-11-2017 (Photo by Kim Carpenter on Flickr, Creative Commons license)

One study of the National September 11 Memorial and Museum’s “Tribute in Light” in New York City by a team of ornithologists over seven years found that the light changed the behavior of migrating birds at altitudes up to almost two-and-a-half miles. The birds gathered in high numbers, decreased their flight speeds, and flew in circles, all the while calling. But when the lights went out, the birds resumed their migration. The researchers agreed with other studies “highlighting disorientation due to artificial lighting” on many structures such as sport stadiums, construction sites, and offshore oil rigs. In addition, they found, ”There is mounting evidence that migratory bird populations are more likely to occur in urban areas during migration, especially in the autumn.”

Still, a variety of stakeholders in the Tribute of Light event, including the NYC Audubon and the Cornell Lab of Ornithology, agreed to keep the lights on despite its effect on the birds unless conditions were particularly hazardous and then they would shut off the lights for short periods. These shut-offs were enough for birds to continue on their way.

In Pittsburgh, every time the University of Pittsburgh football team wins a game, powerful lights are aimed high in the sky from the tallest campus building. These “Victory Lights” were on for the weekend of October 7-8, 2018 when Pitt won its game against Syracuse. At that time, nature writer and bird blogger Kate St. John was monitoring weather radar and noticed that there were large numbers of migrating birds around Pittsburgh. After she wrote about it, Pitt board members, the Pitt chancellor, and the Executive Director of Audubon Society of Western Pennsylvania agreed that the university would dim the lights for 15 minutes out of every illuminated hour so that trapped migrants could continue their journeys.

A Season on the WindSt. John was able to use weather radar to figure out the movements of migrating birds and how they react to human-related obstacles, because in 2004 the National Oceanic and Atmospheric Administration made its national weather radar data freely available to every interested person. Kaufman, for example, writes about how he and other birders check radar information on their computers every day and night during spring and fall migrations so they know when and where large pulses of migrating birds will land to rest and forage.

A wide range of other researchers, such as Jeffrey J. Buler, who runs an Aeroecology Program at the University of Delaware, uses radar data to study the effects of lighting on migrating birds and how such brightly-lit urban areas attract greater densities of migrating land birds. Such information has led to Lights Out and Dark Skies movements in Toronto, Chicago, and other major North American cities.

Still another study using radar found that migrating birds look for favorable winds and then fly in the atmospheric layers that have them. For instance, many migrating songbirds fly at night because of cooler air and less turbulence. But several studies have also been able to estimate how high most migrating birds fly in relation to human-caused collision threats.

A turkey vulture flies near an office tower

A turkey vulture flies near an office tower (Photo by Finn Maxwell Cousineau on Flickr, Creative Commons license)

The cruising altitude of songbirds averages 500 to 2,500 feet above the ground, raptors, taking advantage of the daytime thermals 700 to 3,000 feet, and waterfowl 200 to 4000 feet. In addition, tall buildings and their windows at 340 million and private residences at 253 million are the largest annual killers of migrating birds followed by powerlines (22.8 million), communication towers (6.6 million) and wind turbines (366,000).

This may be why some studies maintain that “a songbird is 15 times more likely to die during migration than during its long stays in its summer and winter territories,” Kaufman writes. And why some researchers in aeroecology are moving into what they call “aeroconservation” in order to keep not only the birds but the bats and the flying insects they eat safe as they navigate our crowded skies.

 

Purple Martins

One mid-July afternoon near our barn, our son Steve watched two purple martins insect-catching high in the sky. Several days before, down in nearby Sinking Valley, Steve had driven up a private road called Purple Martin Lane and found two large purple martin houses set up by a local Amish family.

The entrance to Purple Martin Lane in Sinking Valley

The entrance to Purple Martin Lane in Sinking Valley (Photo by Bruce Bonta)

“There were at least 50 purple martins using them,” he told me.

The martins he identified here were the 173rd bird species for our mountaintop property, and Steve thought they had come from the Amish farm he had visited because it was only a few miles away as the crow (or martin) flies.

The next time I drove to the valley I looked more carefully for purple martin houses and found two more Amish farms, out in the open, with two active martin houses.  Only one of each had four gourds hanging below, but I learned from Amish friends that they were growing more gourds for those Amish and other interested farm families to use as purple martin housing.

Purple martin housing

Purple martin housing (Photo by Adam Woodis on Flickr, Creative Commons license)

Purple martins live throughout North America, but those in the eastern part of the continent are wholly dependent on housing provided by humans. That’s because Native Americans fashioned homes for them from hanging gourds and pioneering farm families did the same. Both were interested in these large swallows that specialize in flying insects especially the flies that swarmed over their game and other food. This thousand-year human/martin relationship led to a remarkable trust on the part of purple martins toward humans, so much so that researchers believe purple martin housing should be erected within 100 feet of a human dwelling and 40 feet from the nearest tree.

Pennsylvania is close to the northeastern edge of the contiguous range of purple martins even though they nest as far north as southern Canada. Between Pennsylvania’s first and second atlasing periods, the martin population “contracted dramatically” according to John Tautin, writing in the Second Atlas of Breeding Birds in Pennsylvania, with losses most notably in northeastern and southwestern Pennsylvania, and central Pennsylvania’s Mifflin and Juniata counties. However, as I discovered, martins are more common in Pennsylvania where there are Amish farms.

A pair of purple martins on an Amish farm in Pennsylvania

A pair of purple martins on an Amish farm in Pennsylvania (Photo by fishhawk on Flickr, Creative Commons license)

While these cavity nesters have adopted apartment and gourd nesting in the East, their ancestral nest sites were abandoned woodpecker holes in dead snags. Yet, by 1900, the eastern purple martins had converted almost entirely to human-made houses.

Purple martins are the largest swallows in North America. The males are entirely purple but appear black in the field while female purple martins are pale below with a pale collar and forehead. They arrive in northwestern Pennsylvania from their winter homes in Amazonia Brazil near Manaus in late April, according to studies by Dr. Bridget Stutchbury and her students. By putting geolocators on five purple martins, those researchers found that it took the birds on average 23 days at 180 miles a day including a nonstop Gulf of Mexico crossing to reach northwestern Pennsylvania. However, one martin made it in 13 days which meant that it flew 300 miles a day.

Male purple martins arrive first and try to claim as many compartments in a birdhouse as possible and sometimes multiple gourds too. If each porch in a birdhouse is divided by a barrier that prevents a male seeing into the adjacent apartments, a single male defends less territory. This enables more martins to occupy a house.

A pair of purple martins, the male on the right

A pair of purple martins, the male on the right (Photo by Andrew Reding on Flickr, Creative Commons license)

To attract a female to his nest, a male flies from his nest cavity, sailing in a wide arc, and then returns to his nest site, ending in a steep dive. As he lands, he enters his nest, turns around, pokes his head out and sings. A female, more interested in evaluating the nest cavity instead of the male, visits it repeatedly over several hours. Finally, he treats her as his mate and starts accompanying her (mate-guarding) when she leaves the nest site. After several days they move in together and greet each other whenever they are separated.

Purple martins have a wide variety of calls and songs, but the male uses a series of clicks called the “croak song” and the female a “chortle song” during courtship. Most famous is the very loud “dawn song,” which is used before daylight perhaps to attract other martins to the bird house.

Studies of nest preferences for purple martins indicate that they like the higher compartments in bird houses and the deeper they are, the more fledglings they can produce. Best of all are the gourds that are so deep that the martins can raise seven young in them instead of the more usual four in the birdhouse compartments.

Nest-building in Pennsylvania begins in early to mid-May and is mostly done by the female purple martin, although the male may collect green leaves and sometimes starts nest-building by gathering a few twigs or leaves. But once the female begins, he either accompanies her while she gathers nesting material or sits near the nest cavity and watches.

A purple martin nest with eggs

A purple martin nest with eggs (Photo by OakleyOriginals on Flickr, Creative Commons license)

She builds her nest out of twigs, stems of herbaceous plants, leaves, and mud, but each pair designs their own nest so they vary widely in shape. The depressed nest bowl is filled up with green leaves that often hide the three to seven white eggs the female lays. In Pennsylvania, returning martins reuse the same nest cavities and fledge more young than those that use clean compartments.

The female has a brood patch and is thought to be the incubator during the 15 to 18 days of incubation, but the male often relieves the female for long periods and sits on the eggs.

Purple martin fledglings

Purple martin fledglings (Photo by OakleyOriginals on Flickr, Creative Commons license)

The altricial young hatch and are brooded by the female until their eyes open in 10 days. Both parents feed the nestlings and when they are 12 days old, they cluster together near the entrance hole to greet their parents. By the time they are 17 to 21 days of age, they have their feathers and are exercising their wings by stretching and flapping. Finally, they fledge when they are 28 to 29 days old. In northwestern Pennsylvania that is mid-July on average.

Their parents continue to feed them for several days, but the young begin catching insects on their own and are fully independent seven to 10 days after they fledge. Then they join other fledglings in roosts.

James Hill at the Purple Martin Conservation Association in Edinboro, PA

James Hill at the Purple Martin Conservation Association in Edinboro, PA (Photo by Bruce Bonta)

Back in 1990, my husband Bruce and I visited James Hill, who had founded the membership and research-based Purple Martin Conservation Association in Edinboro, Pennsylvania. Already, Hill had set up a variety of nesting apartments and assemblages of gourds to figure out the kinds of nests purple martins preferred. He also published an excellent quarterly periodical called Purple Martin Update, which is still being published.

Today the PMCA is housed at the Tom Ridge Environmental Center under the leadership of Joe Siegrist. In late summer he takes people on pontoon boat tours near sunset to view the huge martin roost of 20,000 at Presque isle Bay, which draws in birds from at least a 250-mile radius. Under their program called Project Martin Roost they’ve discovered at least 350 premigratory roosts in eastern North America and Canada. Most of these roosts are so large they show up on weather radar.

Usually the roosts are over large bodies of water with cover from reed beds and long brushy islands, but in urban and suburban settings they roost in trees or on manmade structures such as bridges and pipes. The farther south these roosts are, the longer the martins remain. Some are used from eight to 12 weeks.

A purple martin flying at the Codorus State Park in Pennsylvania

A purple martin flying at the Codorus State Park in Pennsylvania (Photo by Henry T. McLin on Flickr, Creative Commons license)

But Stutchbury’s geolocator studies show that once the Pennsylvania birds set out for the south, they fly almost nonstop until they reach Central America as soon as five days later. Then they rest before continuing on to Brazil more slowly than when they head north in the spring.

Other research projects the PMCA engages in with citizen scientists are a Scout-
Arrival Study that tracks the northward migration of the first martins to be sighted at individual colonies and Project Martin Watch, a continent-wide effort to study the nesting dates, number of eggs laid and hatched and how many nestlings survived. They’ve also been banding martins since 1987.

Wet weather is the largest threat to purple martins. If there is a long, cold, rainy spell in June and July, most of the year’s progeny will perish of cold, drown in their nests, or die of starvation since martins don’t fly in wet weather. European starlings and house sparrows may take over martin nests, so martins depend on their human landlords to remove the non-native invaders.

Owls and snakes are also a threat and deeper cavities make nests harder for owls and other avian predators to reach into. Snake guards installed on birdhouse poles can keep them away from the birdhouses.

With enough folks willing to be purple martin landlords, the eastern population of this beautiful bird should grow and thrive.

 

Surveying Breeding Birds

Ever since I began documenting bird species on our central Pennsylvania mountaintop back in 1971, bird numbers and species have been declining, not only here but throughout the world. Most of these estimates by scientists are based on a wide variety of bird counts and studies, especially in North America and Western Europe. But in the last couple decades, due to the ease of submitting bird lists online, birders and scientists worldwide have joined in.

The Important Bird Area sign at the entrance to the hollow, chewed by a porcupine

The Important Bird Area sign at the entrance to the hollow, chewed by a porcupine (Photo by Dave Bonta on Flickr)

Here in Pennsylvania we’ve conducted two breeding bird atlasing projects (1983-1989) and (2004-2009). In addition, Audubon Pennsylvania launched its Important Bird Areas breeding bird point count in 2003. Since our Bald Eagle Ridge property is part of IBA#32, my son Dave and I participated in the count from 2005 to 2014. Each time we followed the identical protocol, counting birds at the same 15 points 500 feet apart in some of the varied habitats on our property.

That first year we conducted two counts. The one in May yielded 48 species and the second in June 47 species. But by 2014, when the IBA point count project was discontinued, our species number was down to 37.

The steep slopes of Laurel Ridge

The steep slopes of Laurel Ridge (Photo by Dave Bonta on Flickr)

I had grown increasingly dissatisfied by this approach because I knew that we had far more species breeding on our mountain than the point count indicated. And the route that we had to follow in less than three early morning hours up and down steep slopes, was becoming more difficult as I entered my seventies.

In the meantime, the Pennsylvania Society for Ornithology started its ongoing Breeding Bird Blitz in 2015. This survey encourages teams of birders to cover the commonwealth during four days in mid-June in order to get a quick snapshot of the state’s breeding birds and put their reports on eBird, the online reporting system that birders throughout the world use.

Last June I decided to spend three days of the Breeding Bird Blitz on foot searching for breeding birds on our mountain, following no protocol but my own knowledge of an area I have been living in and studying for almost five decades.

A cerulean warbler at Raccoon Creek State Park

A cerulean warbler at Raccoon Creek State Park (Photo by Steve Valasek in Flickr, Creative Commons license)

I examined Pennsylvania Audubon’s 13 priority birds list for the state, all of which are threatened in terms of the species’ long-term survival according to rigorous analysis by qualified scientists. I hoped to find at least a few of the songbirds, specifically cerulean warblers, wood thrushes, golden-winged warblers, and black-throated blue warblers, all of which have nested here in the past. There was also a chance that I would find a breeding American woodcock or bald eagle, the latter now nesting regularly at the other end of our Brush Mountain portion of Bald Eagle Mountain.

But I was absolutely certain that I would not find breeding piping plovers, northern goshawks, bobolinks, prothonotary warblers, Canada warblers, common terns, and grasshopper sparrows because we have no habitat for those species.

On day one—June 16—I was out before 6:00 a.m. and counted an easy 11 species singing in our couple acres of overgrown yard—gray catbird, chipping sparrow, eastern towhee, indigo bunting, field sparrow, red-eyed vireo, common yellowthroat, eastern phoebe, song sparrow, eastern wood-pewee, and tufted titmouse.

I added other species as I hiked up the forested Dump, Short Circuit, and First Field trails, through our 43-year-old Norway spruce grove, over to the still-filled vernal ponds, along Sapsucker Ridge Trail to the Far Field and back on the Far Field Road, Laurel Ridge Trail and Guesthouse Trail—a two –mile circuit that brought me home by 7:22 a.m. Altogether, I garnered 27 species, several of which were repeats from my yard count but also it included six scarlet tanagers, nine ovenbirds, four hooded warblers, three black-throated green warblers, and one black-and-white warbler. All of those species were listed as migrating songbirds whose numbers have been cut in half since the 1960s, which sounded about right, because I had passed whole areas on our mountain that were silent in our closed canopy forest.

A wood thrush in Allegheny County

A wood thrush in Allegheny County (Photo by Tom Benson on Flickr, Creative Commons license)

I especially remembered back in the 1970s the wood thrushes that nested in many of our mountain laurel shrubs, some as close as 10 feet from one another. Yet today our bushes are mostly dead and dying from a leaf fungus and wood thrushes have deserted most of our forest. I still can hear their ethereal songs, but I have to hike much farther to find even one wood thrush.

The following morning I walked part way down our hollow road to record three Acadian flycatchers and two worm-eating warblers, but with all the rain we had been having, our small stream, which is usually low by mid-June, was flowing as strongly as it does in early spring and was so noisy that it was difficult to hear much except the loud birds—more scarlet tanagers, red-eyed vireos, and the Acadian flycatchers.

Finally, I hiked up a flooded Dogwood Knoll and along the soggy Ten Springs Trail to hear an eastern wood-pewee, chorusing tufted titmice, and at last, a wood thrush. Again, I covered about two miles in the early morning.

Down the hollow road next to an old black birch

Down the hollow road next to an old black birch (Photo by Dave Bonta on Flickr)

The last day, which was hot and humid, I was down our hollow road before the sun rose at 5:38, but I only added more numbers to my list even though I walked most of the mile-and-a-half road. Still, the noisy stream continued to defeat me and again I retreated upslope, this time to Greenbrier Trail where I picked up American redstarts, hooded warblers, eastern towhees, a common flicker, eastern wood-pewee, scarlet tanager, and red-bellied woodpecker, several northern cardinals, and a brown-headed cowbird.

By then my socks and boots were thoroughly soaked by the invasive, knee-high, Japanese stiltgrass that clogs the old logging roads and, incidentally, was brought in on logging trucks back in 1991, before we could purchase this part of our property. Already, it was heating up, and by the time I reached Butterfly Loop around our 37-acre First Field, it felt like a blast furnace. Still, I persisted and was rewarded by a gorgeous, singing rose-breasted grosbeak, but not a golden-winged warbler as in years past.

Back at our yard, a cerulean warbler and gray catbird joined the morning chorus. The veranda eastern phoebe was sitting on her second clutch of eggs, the yard nesting blue-gray gnatcatcher called, and a chipping sparrow buzzed louder than usual.

Then it was time to tally up my numbers and species of birds during the three-day period. Even though I had covered the IBA point count area Dave and I had followed as well as other portions of our property, I ended up with 38 species, only one more than we had gotten back in 2014.

A red-eyed vireo in Chester County

A red-eyed vireo in Chester County (Photo by Kelly Colgan Azar to Flickr, Creative Commons license)

The winner in numbers remained the same—the red-eyed vireo—with 33—followed by 17 eastern towhees, 12 hooded warblers, 10 ovenbirds, scarlet tanagers, common yellowthroats and indigo buntings, seven American redstarts and eastern wood-pewees, five wood thrushes, and three cerulean warblers and black-throated green warblers. But alas I found not even one black-throated blue warbler or golden-winged warbler and no surprise birds either. I did, however, find all five of the most common bird species in Pennsylvania, according to the Second Atlas of Breeding Birds in Pennsylvania—American robins, song sparrows, chipping sparrows, red-eyed vireos, and gray catbirds.

But since I had been listening to and counting singing species since late April, I had also recorded the songs of other breeders here, for instance, blue-headed vireos, brown thrashers, Louisiana waterthrushes, whip-poor-wills, wild turkeys, barred owls, yellow-billed cuckoos, black-capped chickadees, white-breasted-nuthatches, common ravens, American crows, house wrens, common grackles, pileated, hairy and downy woodpeckers, as well as the calls and courtship displays of red-tailed hawks, Cooper’s hawks, and turkey vultures, in all at least 57 species.

This exercise led me to conclude that both Breeding Bird Blitzes and in depth, breeding season coverage of as much habitat as possible in Pennsylvania are necessary to assess the numbers, species, and overall health of our breeding birds, a task that continues to be done by both professionals and amateurs who cherish our birds.

 

Moosic Mountain

Last May seven of us stood atop Moosic Mountain listening to the thin, quick, ascending notes of a singing prairie warbler. It was mid-afternoon after hours of pouring rain and the mountain was still swathed in fog.

A heath barren in the Eales Preserve on Moosic Mt.A heath barren in the Eales Preserve on Moosic Mt.

A heath barren in the Eales Preserve on Moosic Mt. (Photo by Bruce Bonta)

Six of us, Mike and Laura Jackson, George Mahon, Sam Dietz, Bruce and I, had traveled three and a half hours from west-central Pennsylvania to explore at least a portion of this 32-mile-long mountain northeast of Scranton in Lackawanna and Wayne counties. At its tallest point–2,323 feet– it is the highest place on the Pocono Plateau. Described by biologists as having “one of the best examples of ridgetop heath barrens in the northeastern United States,” much of it is a mixed forest of small tree species–primarily pitch pine and scrub oak–with an understory of huckleberry, blueberry, rhodora, sheep laurel and other small shrubs.

Outside nearby Jessup, thousands of acres of this unique landscape are preserved at The Nature Conservancy’s 2,250-acre Dick and Nancy Eales Preserve, the 5,756-acre State Game Lands # 300, and the connecting 2000-acre Moosic Mountain Tract in Pinchot State Forest.

Rhodora in bloom at the Eales Preserve

Rhodora in bloom at the Eales Preserve (Photo by Bruce Bonta)

We spent what was left of the afternoon walking a small portion of the Eales Preserve, listening to and watching the many bird species as well as enjoying the flora under the direction of David Trently, a local birding guide and expert on the nature of this unique mountain. It was the third weekend in May and the lovely, rose-purple flowers of the rhodora shrub were in bloom. Another small shrub, sheep laurel, which is in the same genus as mountain laurel, was still in deep pink bud, while the lowbush blueberry shrubs displayed their white and pinkish, bell-shaped blossoms. Here and there small shadbush trees, which in our area are usually blooming by the second or third week in April, were still covered with white flowers, at the same time that clumps of pink lady’s slipper orchids were in bud.

Beside a small pool, we knelt to look closely at the dark red, sticky, opening sundew leaves that this carnivorous plant uses to close and trap insects for food. Then we stopped to admire the bright orange of a red eft, the terrestrial, sub-adult of the red-spotted newt, resting on a lichen-covered rock. We also heard the rattling trill of a calling gray tree frog. When we reached a meadow, Trently told us that one of the rare species at the Eales Preserve was a Leonard’s skipper, a large, reddish-brown butterfly with bright white spots that appears in late August and feeds on grasses.

But there was no doubt that the Eales Preserve was mostly bursting with birds during their peak of migration, and as members of the Juniata Valley Audubon Society, we were pleased at the variety we saw and heard despite the misty, moisty day. Since prairie warblers like scrubby, successional habitats, we were not surprised to hear them, but we were surprised to find one perched in a tree with three scarlet tanagers and a black-and-white warbler, the latter two species common breeding birds in the mature deciduous forests of central Pennsylvania.

A chestnut-sided warbler

A chestnut-sided warbler (Photo by Yankech gary on Flickr Creative Commons license)

Chestnut-sided warblers, also breeders in scrub and low second growth forests, were expected when we heard and then saw their golden-topped heads and chestnut-colored sides, and we were delighted to learn that the yellow-rumped warblers, with golden crowns in addition to their bright yellow rumps, nested in the Preserve.

In fact, almost all the birds we saw there were breeding including a singing, black-necklaced Canada warbler, a buffy-spectacled Swainson’s thrush, nine black-masked, pointed crested, cedar waxwings, a flashy, black and white, rose-breasted grosbeak, a black and orange American redstart, a black masked, common yellowthroat, a black-throated green warbler, and a black and orange Baltimore oriole, two magnolia warblers, two rusty-brown veery thrushes singing their breezy, ethereal, downward scale song in the surrounding forest and too many eastern towhees to count. It may have been a chilly 56 degrees, but the humidity and the brilliant colors and songs of so many birds seemed reminiscent of their southern winter homes in tropical and subtropical forests.

A bay-breasted warbler

A bay-breasted warbler (Photo by Andy Reago & Chrissy McClarren on Flickr, Creative Commons license)

In addition to the singing of the veeries, I was thrilled by the sight of a bay-breasted warbler, the only non-breeding bird species we saw that day. This large, handsome male warbler has a black face, a buff patch on either side of his neck, and a reddish-brown patch on the top of his head and another on his throat and either side of his white breast. This species breeds across the boreal regions of Canada. I used to see these warblers during migration on our mountain but I hadn’t seen one in years. Apparently, their numbers fluctuate from year to year depending on outbreaks of spruce budworms and other caterpillars.

Altogether, we counted 33 bird species on the Eales Preserve during only a mile or so of walking atop the high, relatively flat, mountaintop terrain. This property has 12 miles of trails open to hiking and biking, and we regretted that we couldn’t explore more of it. Still, we were glad that in 2001 the Pennsylvania chapter of The Nature Conservancy had stepped in, with the help of local activists, to purchase this unique area that had been slated to become a business park. Since then, the Eales generosity has allowed the Conservancy to continue to expand the preserve and conduct prescribed burning that is necessary to maintain the fire-dependent natural community.

A prairie warbler

A prairie warbler (Photo by Kenneth Cole Schneider on Flickr, Creative Commons license)

Early the following foggy, windy morning, we drove to SGL # 300. On this gamelands there were many singing prairie warblers, and we had an excellent view of one singing from the top of a dead snag. In the scrub oak habitat interrupted and cinnamon ferns were unfurling and Canada mayflower was in flower. It was still red eft weather and we found four on the gravel road and two more on rocks. Spring peepers called and spotted salamander egg masses floated in Robinson Pond, a manmade wetland/marsh impoundment of about 50 acres with cattails, phragmites, pole stage birch trees, and steeplebush shrubs.

Watching and listening for birds in the fog at SGL 300, left to right, Mike Jackson, David Trently, Laura Jackson, the author

Watching and listening for birds in the fog at SGL 300, left to right, Mike Jackson, David Trently, Laura Jackson, the author (Photo by Bruce Bonta)

As we walked along the network of gated roads, we found starflower, wild oats, and dwarf ginseng in bloom. But it was the birds that delighted and amazed us, singing vigorously in a habitat that shifted from patches of more mature trees to shrubby scrub oak and pitch pine. We saw and heard many of the same species we had seen at the Eales Preserve—black-and-white warbler, veery, yellow-rumped warbler, rose-breasted grosbeak, black-throated green warbler, for instance—but in a large planting of small birches field sparrows sang, a black and yellow magnolia warbler, which prefers to breed in low conifers, perched and posed in a red pine tree, and a black-throated blue warbler sang in the mature forest along with a scarlet tanager and an ovenbird.

Once again the bay-breasted warblers were my birds of the day. This time four were perched together in gray birches and were close enough that we could clearly see that three were either the duller colored immatures or females and the fourth was a brightly-hued male.

Even with seven pairs of eyes and ears alert to every bird species, we were grateful for Trently’s superior birding skills, especially when we heard what sounded like a scolding red squirrel but turned out to be an uncommon call of a common yellowthroat.

The tracks of a black bear

The tracks of a black bear (Photo by K Young in Wikimedia, Creative Commons license)

In fact, we saw no mammals on Moosic Mountain during our two days, although it is known to have a population of snowshoe hares as well as the usual black bears, bobcats, coyotes, and deer. We did spot fresh tracks of a black bear in the muddy road of SGL # 300 and those of deer. We also had none of the views at 2240 feet that visitors on clear days rave about.

Only when we dropped down to Lake Ariel did the sun break through and deliver a new suite of birds in the brushy trail near the lake and the lake itself, for example, bald eagle, red-shouldered hawk, ruby-throated hummingbird, belted kingfisher, yellow-bellied sapsucker, alder and least flycatchers, blue-gray gnatcatcher, warbling vireo, and barn swallow.

Then it was time to leave. In spite of the weather we had enjoyed our time on Moosic Mountain and our intimate looks at 53 bird species including 12 species of warblers.