Ghost Bird

leucistic redtail 1“What is it?” the e-mail asked.

Attached to it were four photos from a trail cam our caretakers, Paula and Troy Scott, had set up behind the spruce grove. The photos showed a large white raptor feeding on top of a carcass the Scotts had secured to lure in wintering golden eagles for an ongoing region-wide study.

Stuck inside most of last winter with a deep muscle tear in my left calf, I eagerly awaited photos of the many wild creatures that visited their three trail cams. But this bird was a real puzzle.

The raptor’s back and head were white except for the tips of a couple black primary wing feathers, a small black patch on top of its head and another on its neck. Its breast, belly, and tail coverts were pure white and so were the feathers on its legs. Then I looked at the tail, which was mostly white with a couple bands of red. The mystery bird was a red-tailed hawk.

Like most people who see a white red-tail, I thought I was seeing a rarity. But according to William S. Clark and Brian K. Wheeler, authors of Hawks of North America, a Peterson Field Guide, “Partial albinos, varying from almost all white birds to some with just a few white feathers, are fairly common and are reported from almost all areas. Most birds are from half white to mostly white.”

Our bird was mostly white and did not have a dark area on its nape as most do. In addition, our bird had dark eyes and an orange beak and talons.

leucistic redtail 2I expected to find more information about white red-tails in my many books on birds, but even The Birds of North Americas definitive account of red-tailed hawks failed to mention this phenomenon.

I was more successful when I Googled “albinism in birds and animals” and “partial albinism in red-tailed hawks.” The former convinced me that terms for white creatures varied, although pure albinism in birds is caused by a genetic mutation that interferes with the production of the melanin or dark pigment that determines the black color of birds’ feathers.

One source declared that partial albinism is now called “leucism” and that the term comes from the Latin “leuk” or Greek “leukos” meaning “white.” But another source, which I found easier to understand, had a chart that differentiated between three types of albinism.

A true albino is white or pink all over with pink eyes and has little or no ability to produce colors. Those are indeed rare among mammals and birds. For instance, Henry Kendall, a master falconer in St. Louis, has reported 600 sightings of oddly-colored red-tails throughout North America in ten years. Of those, only one was a pure white albino with pink eyes.

Those eyes are pink because red blood cells in the retinal blood vessels beneath are not hidden by pigment. For this reason albino birds and animals often go blind since they don’t have pigments in their eyes to protect them from sunlight.

A leucistic creature is white or pink all over, its eyes are usually blue, and it has little ability to produce color. Another source says a leucistic animal is not pure white, its pigmentation is diluted, and its plumage is lighter than usual but not pure white. David Bird, an ornithologist, recently defined leucism as “a partial loss of melanin pigments” in Bird Watcher’s Digest. That simple definition suited me.

leucistic redtail 3A partial albino, also called a partial leucistic by some experts, has small portions or patches of white, its eyes are a normal color, and it has the ability to produce most normal colors. Some sources call this the piebald effect.

By then, I was thoroughly confused. Our bird had more than small patches of white. So too did the red-tails folks reported on Eddie B. Horvath’s blog devoted to white red-tail sightings throughout North America. I scanned the dozens of reports and found several from Pennsylvania. One, from near Quakertown was “absolutely pure white.” Another from Lake Wallenpaupack was “100% white.” A third, on Route 706, 10 miles from Montrose, was “completely white.” Most recently one was sighted at the Flight 93 memorial site on March 12, 2012 and again on August 13, 2012.

Seeing the same bird twice in one area is fairly rare. We and the Scotts saw our bird only on the trail cam once, last Valentine’s Day, and never in the air. Years ago I observed a white woodchuck for several minutes at the Far Field thicket and never again. And once my son, Steve, and I spotted a white deer in our forest as we were driving down our road. It too disappeared.

These white animals lack protective camouflage and are easy for predators to spot. White deer and white bears are also prized by hunters, and one website reported a small white black bear in Pennsylvania was legally killed by a hunter from Spring Mills back in 2006.

But raptors are protected by the National Migratory Bird Act, and when a white red-tail, which had lived in south Texas for several years, was shot and left on a two-lane road, residents were angry and posted a $1000 reward for any information about the perpetrator. A local scientist was quoted as saying that “the average citizen loves white red-tails.”

leucistic redtail 4Writing for the Times Union in Albany, New York several years ago, Richard Guthrie reported the presence of at least six white red-tails with dark eyes in the area. All were females and all were paired with normal-colored red-tail males and were nesting.

Despite all these tales of white red-tails, researchers reported years ago that the most common albino or partial albino wild bird species is the American robin. A whopping 8.22% of all such birds were robins, but other researchers hypothesized that it could be because robins are commonly seen and often live in our yards.

Another reason for the high number of white robins may be because they don’t migrate far. Melanin pigments make feathers that are strong and last longer and the lack of such pigments in albino or partial albinos weaken birds, especially those that migrate long distances.

Lost in the world of white creatures on the Internet, I also learned that New York State has the largest white deer herd in the world. Back in 1941 in Seneca County, 10,600 acres were fenced to enclose the Seneca Army Depot, isolating a small herd of white-tailed deer, some of which had white coats. In the 1950s, although hunting was allowed in the Depot, the commander declared that hunters were forbidden to shoot white deer. Today, even though the army is cleaning up the site and moving out, of the 700 deer inside the fence, 300 are white. There are folks up there hoping to save the herd and they mention a prophesy supposedly made by the Lenape, who said that “It has long been predicted that there would come a time when a white male and female deer would be seen together and that this would be a sign to the people to come together.” I presume they mean that if enough like-minded people come together, the white deer herd will be saved for the many people who are interested in seeing them.

leucistic redtail 5Some Native Americans called white deer “ghost deer,” and I think of our white red-tail as a “ghost bird,” because we only saw it once and only on photographs. Artist and writer Julie Zickefoose was luckier. She spotted a pure albino red-tail during a drive from her rural Ohio home to Columbus on October 11, 2012. She posted several photos of it on her blog and described it as “something searingly beautiful, transformative, a vision, a bolt from the blue,” a description, I think, that those who have seen such birds would agree with.


Game cam photos courtesy of Paula Scott.

Allegheny Front Hawk Watch

Marcia with Gene and Nancy Flament and Tom Dick (standing) at "the Ritz"

Marcia with Gene and Nancy Flament and Tom Dick (standing) at the bench Gene made--"the Ritz"

“It’s the Cadillac of hawk watches,” my husband Bruce said as we were leaving the Allegheny Front Hawk Watch.

Not only does it have a wide, grassy field flat enough for lawn chairs, a picnic table, and a portable restroom back near the parking area, but also a pair of platform benches, fondly called “the Ritz” by some visitors, positioned for optimal hawk-spotting.  What it doesn’t have are huge boulders to clamber over and perch on like many hawk watches in Pennsylvania.  For older folks like us, whose balance might not be as good as it once was, the Allegheny Front Hawk Watch is perfect.

I settled down on one of the benches at the edge of the mountain next to Gene Flament (the builder of the benches) and his wife Nancy and didn’t move for hours.  Above me, in the clear, blue sky of a breezy, early November day, raptors funneled southward.  With the Flaments, their son Randy, and the official counter of the day, Jim Rocco, we didn’t have to wonder what species any bird was no matter how high in the sky it flew.  These folks are all hardcore raptor watchers who were eager to share their knowledge with us.

Golden eagle taking off from a pine tree on Brush Mountain

Golden eagle taking off from a pine tree on Brush Mountain

Two golden eagles had already sailed past before our arrival, shortly before 10:00 a.m., and we hoped it would be a golden eagle day because when the wind is out of the east in November, as it was that day, adult golden eagles are numerous.  Below us, we could see the field where Trish Miller and Mike Lanzone, of the Powdermill Nature Reserve and Todd Katzner of the Aviary, had live-trapped and radio tagged two golden eagles for the first time in 2006. Since our mountain — the westernmost ridge in the ridge-and-valley province — is the alternate migration corridor for golden eagles in the fall, where Trish Miller trapped and radio tagged another golden eagle in 2007, we had wanted to see this particular hawk watch on the eastern edge of the Allegheny Plateau. (See my three earlier columns on the golden eagle trapping project: Golden Eagle Days (Part 1), Golden Eagle Days (Part 2), and Golden Eagle Redux.)

In quick succession, at 10:20, 10:21, and 10:38, three adult golden eagles soared past overhead, their golden crowns and napes visible on their mostly dark bodies. And that was it for us, but altogether nine golden eagles passed the hawk watch throughout the day.  Not an outstanding day for golden eagles at this hawk watch, which had as many as 51 on November 23, 2003, but with a seasonal average of 217, the chances of seeing at least a few on a November day are excellent. After all, as Tom Dick, the property owner, has said, “the golden eagle is the whole reason for the Allegheny Front Hawk Watch.”

Probably the best bird we saw was a northern goshawk that swept past at 12:30, its dark hood and white eyebrow line making it unmistakable.

“Oh, that’s a good bird,” Randy said, probably knowing that of the yearly average of 13 birds at this site, most are seen during spring migration in March and April and even then, four were the most seen on a day back on April 14, 2003.

Raptor i.d. signboard at the Allegheny Front Hawk Watch

Raptor i.d. signboard at the Allegheny Front Hawk Watch (click to see larger)

I was also pleased to have beautiful views of three of the 12 red-shouldered hawks that flew past during the day.  The first accompanied several red-tailed hawks, and all were lit up by the sun.  The second was high in the sky, its wings flapping, its neck craning.  But the third flew low and directly overhead, displaying its rufous belly and black and white tail.

As with other species we saw (two northern harriers and a sharp-shinned hawk), October is their peak month with 82 for red-shoulders on October 26, 2004. That day must have been a marvel for those watching because it was also the one that had the highest red-tailed hawk count (1,156).

We didn’t see that many red-tails during our visit, but it was a red-tailed hawk day. In fact, it was the first bird we saw when we arrived as one dove and screamed at the carved owl decoy displaying a couple ruffed grouse feathers atop a pole stuck in the grass. I lost count of red-tails after 30 because often there were three to five at a time in the sky, coming in from every direction as if they were converging for a party. We saw the larger females and smaller males, dark phase and light phase, most with white breasts and black streaks across their light bellies except for the dark phase with its dark brown breast and belly — 113 in all for us and 148 for the day.

Tom Dick and Randy Flament at the Allegheny Front Hawk Watch

Tom Dick and Randy Flament scan the sky for raptors

During lulls in raptor-watching, we admired the lovely panorama of fields and forests below. At 2,850 feet, the Allegheny Front Hawk Watch is the highest hawk watch in the state and looms 800 feet above the valley. Located in Bedford County on Shaffer Mountain near the Somerset County line, the property is owned by both Tom Dick and his wife Sally who generously open it to the public during spring and fall migrations.

Members of the Allegheny Plateau Audubon Society, centered in Johnstown, help to maintain the site and have been monitoring the fall migration from late August through November since 1989. On a clear day, such as we experienced, we could see as far north as Blue Knob, the second highest mountain in Pennsylvania, and as far south as the I-70 corridor. With my binoculars, I could watch for osprey over Shawnee Lake and spot the Dunning Creek Wetlands near Pleasantville in Bedford County.

The Dunning Creek Wetlands, a 170-acre nature sanctuary also owned by the Dicks, was created from a failed farm in cooperation with the United States Fish and Wildlife Service’s Partners for Wildlife program (now renamed Partners for Fish and Wildlife). Originally ditched and drained to raise crops, the farmland was often too wet to harvest and was abandoned in the late 1970s. By restoring the wetlands back in 1991, they attracted shorebirds and waterfowl in impressive numbers.  Once Tom Dick spotted tundra swans at the wetland from the Allegheny Front Hawk Watch and made a fast exit down the winding mountain road and back up the valley to the wetlands for a closer look.

Decoy for attracting saw-whet owls at night

Decoy for attracting saw-whet owls at night

Raptors aren’t the only migrating species that are counted at the hawk watch. Volunteers also count monarch butterflies and dragonflies and note the many songbirds they see there, both migrants and residents. A tent on the grassy field provides shelter for those banding migrating northern saw-whet owls. The evening before, Dave Darney had banded 20 of the little owls as well as one eastern screech-owl.

“The mountain is a major migratory corridor for saw-whets,” Tom Dick told us.

It also has the second highest count of spring migrating raptors after Tussey Mountain, which is the second most western ridge in the ridge-and-valley province and the mountain I see from the top of our First Field. From March until May volunteers also count raptors at the Allegheny Front Hawk Watch.

But in spring, some brave volunteers do more than monitor the raptor migration. They tie nylon ropes around their waists and are lowered down the steep mountainside to cut the brush and saplings for better viewing. Other volunteers keep the grass cut on top during workdays.

A weather station records wind direction and speed, all of which is carefully noted during hourly reports online to the Hawk Count site, maintained by the Hawk Migration Association of North America (HMANA), reports they’ve been sending in since 2002.

Visitors on a typical day at the Allegheny Front Hawk Watch

Visitors on a typical day at the Allegheny Front Hawk Watch

But the Allegheny Front Hawk Watch and the raptors they are counting, including the golden eagles, are threatened by the proposed industrial wind farm on Shaffer Mountain — ten turbines north 2.5 miles away and 20 turbines northwest 2.2 miles away. Miller and Lanzone’s golden eagle live-trapping site would be a mere 1.1 miles south of the nearest turbine.

These whirling turbines will be 400 feet high and threaten not only the raptors, but also the many migrating bats that use this corridor, bats that are already gravely threatened with extirpation, due to the white nose syndrome which is wiping out whole colonies throughout the eastern United States. The mountain has been designated a Pennsylvania Natural Heritage Area of Exceptional Significance because it has two of the highest-quality trout streams in the East, an endangered Indiana bat colony, and 11,000 acres of forest with only two dirt roads.

wind tubines on the Allegheny Front near Blue Knob, northeast of Shaffer Mountain

Wind tubines on the Allegheny Front near Blue Knob, northeast of Shaffer Mountain

More than 3,000 people have signed a petition opposing this particular site, and most wonder why a huge former strip mine, two miles from the proposed project, can’t be substituted for it, especially since the same company that proposes to level a pristine area of Shaffer Mountain owns the land. They reason that more than 100 wind turbines have been constructed on the same kinds of strip mines.  Why despoil an area with exceptional value streams, endangered bats, and the major flyway for migratory birds and bats.

Sadly, the wind companies aren’t waiting for the results of Trish Miller’s study of the effects of wind turbines on golden eagles — those turbines made of reinforced Fiberglass, weighing 3,000 pounds or more, and rotating as fast as 200 miles per hour at their tips. Even though wind companies claim that bird deaths are minimal, a turbine site at Altamont Pass in California kills on average 75 golden eagles a year.  Since our eastern golden eagle population is much smaller than the western one, such losses would soon wipe out what Miller estimates is a migratory population of 1,000 to 2,000 eagles.

Must we destroy the planet in order to save it?

Must we destroy the planet in order to save it?

Of course, the golden eagle is one of many raptor species that will be impacted by those spinning blades. And already there is an industrial wind farm on Blue Knob. Another one is slated, also on the Allegheny Front, above Tyrone, and directly across the valley from our home, even though Trish Miller has already discovered that golden eagles like to pause and feed on the Tyrone watershed site during migration.

So little is known about this species in the East that she and her husband, Mike Lanzone, are making new discoveries every year about the migration patterns of these birds that breed in northern Quebec and Labrador and migrate south for the winter to eastern Kentucky and southwestern West Virginia as well as to southern Pennsylvania. Unfortunately, by the time her study is completed, golden eagles and other raptors will have many more wind turbine blades to avoid.

Knowing all this, I found it difficult to believe that the industrial wind farm would be built on Shaffer Mountain. As Jack Buchan of Johnstown, a Shaffer Mountain landowner and member of Sensible Wind Solutions wrote in a letter to the Johnstown Tribune-Democrat, “If [the wind company] is permitted to build there — to degrade exceptional value streams and kill endangered animals — no place will be off-limits to the wind industry in Pennsylvania.”

Visit ShafferMountain.com for more on this ill-advised project, and to learn how you can help stop it and save the golden eagles. If you’re on Facebook, join the Save Shaffer Mountain group.

The second and the last two photos are by Dave Bonta; all others are by Bruce Bonta.

Nature’s Garbage Collectors

turkey vulture above First Field

A turkey vulture soars over First Field in Plummer's Hollow

Like residents of Hinckley, Ohio, who always welcome the first turkey vultures back on March 15, I too await the return of them in March and regard them as one of the first signs of spring.  Usually the day they appear here is windy, and they rock back and forth above First Field, their wings tilted in their distinctive V-shape, which enables them to soar and glide for hours without flapping their wings.

According to recent studies by raptor biologists at Hawk Mountain Sanctuary, most Pennsylvania turkey vultures have returned from Florida or Georgia, but others return from nearby southerly states.  Still others never leave the commonwealth, occupying roosts in southeastern and south central Pennsylvania counties.

Twenty years ago, in late January, I visited the large winter vulture roost at Gettysburg National Park. The center of vulture activity is focused on an area aptly nicknamed “the Valley of Death,” after the battle, although contrary to legend, the vultures did not first appear in the area to clean up the dead horses after the battle in 1863.  Turkey vultures were in the area long before then, and black vultures, previously living only south of the Mason-Dixon Line, didn’t emigrate there until the late 1930s or early 1940s.

Watching hundreds of vultures as they gradually entered the roost at night and vacated it at first light, was a memorable experience.  No wonder Jim and Shannon Lang of Tyrone were excited when vultures chose their 27-acre, wooded property as a seasonal roost in 2006.  Located on a hill above the wooded town park, with houses on side of them, their 1930s-era house and their pool were shrouded with trees that darkened their prospect.  Shortly after moving in, they cut down 25 large trees, and the next year the vultures arrived in March.  They hang out in the four acres of open woods around their house and garage and beyond their pool.

turkey vultures at Gettysburg by Henry McLin

Turkey vultures at Gettysburg by Henry McLin (Creative Commons BY-NC-ND licence)

“They seem to have three or four favorite trees,” Shannon says.  “I call those trees the Radisson.  When they are filled, they go to smaller trees — the Motel 6.”  Those trees are mostly oaks and conifers.  That habitat — partially open under a canopy of large trees to give the vultures room to move around in — is perfect for a vulture roost.  And in southern Pennsylvania, northern Maryland, and northeastern Virginia, according to a study, roost sites were closer to clearings, human residences, roads and permanent streams than roosts in other parts of the United States.  That perfectly describes the habitat of the Lang’s roost because there is a stream on their property and in the park below.

Shannon, who has a degree in wildlife biology, enjoys watching the vultures even though her neighbors think they are spooky and wonder why she doesn’t get rid of them.

“I think they’re fascinating,” she says.  “They add to the wildlife. I like to see them in the morning when,” she tells me, “they are off by 7:30 and back around 7:20 in the evening. You could almost set your watch by them.”

She adds that they are quiet and clean.  Her two sons collect the pellets the vultures cast below the trees, gagging them up while they lie in a horizontal position, their bodies hanging down and heads bobbing.

Shannon has even watched the vultures play.  Once, when their pool was still covered, a turkey vulture landed on it and using its beak, tried to roll a large ball that her sons had left on top of the cover up a slight incline.  Each time the ball rolled back down to the vulture and it tried again. Apparently, its antics kept the entire family entertained for quite a while.

A turkey vulture basks in the last rays of sun before going to roost above a rockslide on Brush Mountain

A turkey vulture basks in the last rays of sun before going to roost above a rockslide on Brush Mountain

The Lang’s roost is a seasonal one and is made up mostly of turkey vultures with a couple black vultures and has about 52 birds.  These communal roosts — winter, seasonal, or year-round — can range from a few birds to several thousand, although the largest are winter roosts because both residents and migrants occupy them.  The one at Gettysburg National Park has held as many as a thousand vultures and those in Florida more than 4,000.

Such roosts are probably used to escape predators, provide opportunities for various social interactions and supply meeting places for possible mates.  But surprisingly little is known about the life history of these common birds.  For instance, researchers believe they mate for life, but they aren’t certain. They also don’t know at what age turkey vultures mate for the first time, but they do suspect that less than half of most populations breed in a year.

Here in Pennsylvania, turkey vultures arrive in early to mid-March, and most eggs and nests are found between April 18 and May 14.  But turkey vultures are secretive nesters, and while researchers think they nest throughout the state, during the first Breeding Bird Atlasing, only one per cent of observations were those of nests.  That’s because the females usually lay their one to three, creamy-white, blotchy eggs in deep recesses such as caves, crevices, and ledges, in mammal burrows, cavities in banks, or in large, hollow logs. Once they find a good nesting area, they often reuse it for long periods.

A mated pair frequently sit together near their nest site for days or weeks before nesting and engage in what researchers call “Follow Flight, something I’ve observed over First Field, when one bird flies behind and above the leading bird, often twisting and turning just as the leader does.  Sometimes the trailing bird dives at the leading one, partially folding its wings and diving directly toward it while the leading bird twists sideways and drops and the trailing bird flies upward again, neither bird touching the other. Other displays, such as ritualized “dancing,” bill-gaping, and wing-spreading have also been observed by researchers before the birds mate on the ground, rocks, or in trees while nibbling or poking at each other’s naked, red heads.

After the female lays her second egg, she and her mate take turns incubating them. It takes between 38 and 40 days for the eggs to hatch young that are downy with naked faces, throats, and crop areas. The parents also take turns brooding them until they are two weeks old and feed the young by regurgitation. By 18 days of age, they are able to stand up and retreat into the recessed nest to escape predators.  They can also stomp their feet, hiss, and perform what ornithologists call “Scare Jump” or “Scare Rush,” when they lunge forward, their heads thrust upward, flap their wings, open their bills, and hiss in a bluff attack.  Such an attack was enough to turn my Uncle Cal permanently against “buzzards,” as he called them when he told me about crawling into a cave outside Pottstown when he was a teenager and meeting the “Scare Rush.”

T.V. chick on a nest in a hollow tree in Michigan, by David Allen

T.V. chick on a nest in a hollow tree in Michigan, by David Allen (Creative Commons BY-NC-SA)

Between 70 and 80 days of age, nestlings become fledglings, flying above the canopy, and leave the nest area for communal roosts when they are 12 weeks old, about the time in August when the Lang’s roost increases in size for a few weeks before the vultures are gone for another year.

Turkey vultures are unique among vulture species because they can smell as well as see their prey, which is why black vultures often follow turkey vultures to a carcass and then bully them away from it.  One early May day, as I approached the Far Field, I spotted a turkey vulture in a tree that spread and shook its wings but remained on its perch.  One of our turkey hunters had told me about a dead deer there.  Then, I noticed a second turkey vulture in the same tree while a third wheeled overhead. After a few minutes, the first vulture soared off.  Suddenly, a black vulture flew up from the ground, sat in a tree a short time, and flew back down on to the dead deer hidden in the grasses below. After picking at the carcass for a few minutes, it flew up to the remaining turkey vulture and chased it away.  Then it too flew off.  Although black vultures are a little smaller than turkey vultures, they always dominate them.

The scientific name for turkey vulture is Carthartes aura, which means “breezy purifier.”  As primarily scavengers, the pH of a vulture’s stomach acid is an incredibly corrosive zero, which allows them to eat rotting flesh that might contain anthrax or botulinum.  In addition, they use it as a weapon projectile, vomiting on any potential predator.  As if that weren’t disgusting enough, they also defecate on their legs because the high ammonia content of their feces, ornithologist David Bird says, probably “kills off potentially harmful microorganisms picked up while standing in and wading through rotting carcasses.”

Such food can most easily be found in a mixed farm and forest habitat such as we have in our area.  There they eat the carcasses of both wild and domestic carrion such as livestock, woodchucks, skunks, raccoons, opossums and deer.  In fact, turkey vultures only moved into Pennsylvania’s wooded mountains in the 1920s and 30s to feed on starved deer.  A study of turkey vulture pellets in North Carolina also found Bermuda grass, pieces of plastic sandwich bags, brown paper sacks, and polystyrene in them, which proved that turkey vultures clean up road kills.  Without them, we would have many dead critters around.

They also hang around landfills, as Keith Bildstein of Hawk Mountain Sanctuary and James Mandel of Cornell University discovered.  They spent 120 days in 2004 and 2005 watching turkey vultures from an unused hilltop at Waste Management, Inc. Landfill in Pen Argyl, Northampton County.  The 30 to 90 turkey vultures that fed there roosted at three nearby communal roosts.  Of those vultures, 10 to 15 stayed 90 to 210 minutes after the local sunset while turkey vultures that fed in nearby farmlands, woodlands, and suburban areas returned to their roosts no later than 30 minutes after sunset. Those vultures that remained at the landfill used hot air thermals caused by two methane venting sites to give them lifts to leave the landfill long after natural thermals had subsided for the night. However, landfill workers found turkey vulture carcasses at or near the base of the vents which suggests that the flares killed them by suffocation or scorching.

Turkey vultures with a roadkilled opossum

Turkey vultures with a roadkilled opossum in Missouri, by Auntie G (Creative Commons BY-NC-ND)

Bildstein and other raptor biologists at Hawk Mountain Sanctuary launched a long-term study of turkey vulture migration in 2003 to, in their words, “learn more about the extent, causes, and consequences of their annual journeys.” They put tiny radio tags monitored by satellite on 24 turkey vultures in order to study both their autumn and spring migrations. According to raptor biologist, David Barber, who is working on this study and recently spoke to our local Juniata Valley Audubon Society, four of eleven turkey vultures that he studied were migratory.  Those that migrated went to Florida and Georgia, but while some go to the same place every year, others seem to adjust to the weather.  They don’t always take the same route.  Some migrate along the coast.  Others go down the Appalachian spine. Pennsylvania birds take a month to migrate making many stopovers and waiting for the thermals to waft them south.  By implanting five vultures with heart-rate loggers, the researchers discovered that they don’t use very much energy to migrate.  The wind does all the work.

Today turkey vultures are a  continent-wide, common species, and Hawk Mountain scientists want them to remain so, unlike the incredible decline of Old World vultures in many parts of Africa and southern Asia, especially in India where an anti-inflammatory drug given to cows has caused kidney failure within 36 hours to vultures that have scavenged the bodies of cows containing the drug. The population fell from 40 million in the 1980s to a couple thousand today, “the most catastrophic decline of a raptor species anywhere,” Bildstein says.

Maybe we should all celebrate the second International Vulture Awareness Day next September 4. It grew from Vulture Awareness Days run by the Birds of Prey Working Group in South Africa and the Hawk Conservancy Trust in England.  I was also pleased to learn about the Turkey Vulture Society, a nonprofit scientific corporation whose “purpose is to promote scientific studies of the life habits and needs of the Turkey Vulture, to protect the vulture and its habitat, and to inform the public of the valuable and essential services this bird provides to mankind and to the environment.”

Turkey vultures heating up in the early morning sun by Linda Tanner

Turkey vultures heating up in the early morning sun by Linda Tanner (Creative Commons Attribution licence)

The two unattributed photos are by Dave Bonta. Click on any of the other photos to view at Flickr.

Golden Eagle Days (Part 2)

Continued from November.

golden-eagle-portrait
photo by Todd Katzner

Then came the great change. After a mild, misty start on December first, the thermometer hit 65 degrees and then began to plummet as the wind picked up. The northwest winds had finally arrived a month late and with it, the following morning, came the eagle researchers. They had a third radio-tag and they meant to use it.

By 10:10 a.m., when I arrived in the blind, they had already counted 12 golden eagles. Behind me in the blind they had a red-tailed hawk in a can. On this bright, cold, windy day they expected visitors from Powdermill Nature Reserve, and they planned a banding demonstration of a red-tail in case they didn’t trap an eagle. That red-tail, Lanzone told me, was “one of the smallest I ever saw.” And then number 13 golden eagle flew past.

After that, there was a lull, but at 10:45 number 14 appeared. Lanzone played the bait even after the eagle flew out of sight.

“They could come in from behind the spruce grove,” Lanzone explained.

The guests arrived, including the head of the Powdermill Nature Reserve, Dave Smith, and a local board member, John Dawes. Other employees from both The National Aviary and Powdermill also watched. The blind was jam packed with eager spectators, and the pressure was on.

But no eagle appeared. Finally, Lanzone weighed, measured and banded the little red-tail on its right leg. That red-tail may have been little but it was mighty and bit Lanzone on the finger, unlike the previous one they had banded.

“All of them have different personalities, like people,” Lanzone said.

In the midst of that, number 15 golden eagle flew past. As numbers 17 and 18 flew over without coming down to the bait, Todd Katzner delivered a mini-lecture on eastern golden eagles. Because easterns are smaller than westerns, it’s a “reasonable probability that it’s a subspecies,” he explained, “even though no work has been done to establish it.”

He also said that in addition to possibly killing golden eagles, wind mills on the mountaintops might deflect the eagles off good lift areas along the ridges.

Then three more golden eagles diverted our attention as they flew up from behind the ridge, and by 12:10 we had counted 21.

“Come on, eagles,” Lanzone muttered under his breath when numbers 22 and 23 appeared with a red-tail on their right. Then they dropped below the tree line again.

Mike Lanzone with golden eagle trap
Mike Lanzone with the bow net (photo: Todd Katzner)

The visitors grew hungry as lunch time came and went. Then another red-tail flew straight from the ridge to the bait. Lanzone sprang the net and made a perfect catch. As they were taking photos of the hawk out in the field with the visitors looking on, an adult golden eagle flew over, giving all of us a perfect view.After weighing, measuring, and banding that hawk, the visitors helped to release it. It hadn’t been the golden eagle we had been hoping for, but no one could deny the excitement of watching the beautiful red-tail take the bait.

The visitors headed back down for their belated lunches, but I remained watching with the researchers. (I had already learned to carry lots of snack food and water.) Altogether, we counted 29 golden eagles. Then the flight was over at 2:30 p.m. even though we continued to peer intently through the blind windows for another hour. All we saw were two flocks of tundra swans.

On December 4 it was 19 degrees and windy. By the time I reached the blind, shortly after 9:00 a.m., 11 golden eagles had already flown past. Number 10 had almost come in, Lanzone told me.

Snow flurries seemed to slow down the flight, although numbers 12 and 13 flew past. Again lunchtime came and went and then, at 2:12 p.m. Lanzone lowered the flaps and whispered, “She’s coming. Nobody move.”

An enormous adult female golden eagle came down on the bait 25 feet from the blind. We had an eye-filling look at this fierce creature as Lanzone sprang the bow net. It snagged on a broken stem of goldenrod. The eagle hesitated and then took off fast. Lanzone was furious. After two immature males, they were eager to catch a mature female.

To add insult to injury, while they were re-setting the trap, two more golden eagles flew past. Then two more, traveling as a pair, also sailed over. Lanzone told me that golden eagles will rarely stoop to bait when they are together.

They spotted another single, number 19. The flaps went down again and tension was high in the blind, but that one too ignored the bait.

We did catch another red-tail. This one came over the ridge. I released it after it was weighed, measured, and banded. Or I tried to release it, holding it firmly by its feet and laying it on its back, as Lanzone instructed, but it refused to turn over and fly off as it was supposed to. It still thought it was caught. Finally, it stood up and spread its wings, posing for photos for several minutes, before Lanzone came out of the blind and helped it to realize that it could fly off.

And that was it for the day. But when Lanzone later checked a hawk count site on the web, he learned that with our 19 goldens we had had, by far, the most goldens in the state both that day and on December 2 with 29.

The following day two goldens passed by 10:00 a.m. It was 22 degrees and snow flurries often obscured Bald Eagle Ridge. Lanzone, Miller, and baby Phoebe were in the blind, and after three fruitless hours of watching, Lanzone asked if I could show him the big talus slope down the ridge where our son Steve had often observed raptors.

Tired of sitting in the blind, I said, “Sure,” and off we went to see if any golden eagles were flying past there.

After a mile, we reached the talus slope, which spreads halfway down the ridge. I picked my way down over the rocks for a short ways and then waited as Lanzone looked over the entire talus slope. He returned after nearly an hour very excited. He was almost certain that the golden eagles would be flying at eye level along this side of the ridge. If only he could get a blind and trap set up there. But where? And how? We walked back along the old, rock-choked, logging road and down the steep Steiner/Scott Trail as he tried to figure out if it would be possible to get a four wheel drive vehicle with supplies within a reasonable distance of the talus slope.After a still, warm day, December 7 dawned cold and overcast with snow squalls and a northwest wind. Lanzone had emailed me late the previous night to say that he and Miller would be here, but he planned to return to the talus slope.

Miller arrived after 10:00 a.m. with Phoebe and told me a story that I could scarcely believe. Lanzone and Lewis Grove, who worked at Powdermill also, had arrived before dawn in a four wheel drive, which they had driven up the Steiner/Scott Trail and down the rocky logging road. Then, making 18 trips in the dark with headlamps on up and down the treacherous, ice and snow-covered rocks, they had set up both a blind and bait. Already they had seen an eagle.

talus slope eagle blind
The talus slope blind in October 2007 (photo: Dave Bonta)

As Miller was setting up, they called on her cell phone to say that three more golden eagles had come by. A few minutes later I looked up and there they were above the ridge.

Then the snow flurried hard and a snow fog developed, which nearly hid the ridges. But shortly after 1:00 p.m., while it was still snowing, Miller spotted a male Cooper’s hawk sitting in a nearby tree. In the hawk came to the bait. It was thoroughly tangled in the bow net, and she patiently untangled it. She put a band on it, and I released it. Unlike the red-tail, the Cooper’s hawk exploded into the air.

In the meantime, Lanzone and Grove counted nine golden eagles before the flurries turned to squalls. By evening, two inches of snow had fallen. That evening Miller, Lanzone, and Phoebe spent the night in our guesthouse.

Still another windy day, 14 degrees and clear. Miller, Phoebe and I occupied the spruce grove blind and Lanzone the talus slope blind. But he missed three golden eagles because the bait had spooked the eagles.

Later, I heard from Lanzone that still another golden eagle had flown in low to look over the situation. That one had landed on a rock next to the bait and bow trap. The eagle had studied it some more, and had finally flown off.

talus-slope-trapping-area.jpg
The trapping spot on the talus slope in October 2007 (photo: Dave Bonta)

With that, the golden eagle saga here ended for the year. Comparing notes with Miller, Lanzone discovered that he saw many more golden eagles at the talus slope than Miller did in the blind. A large number stay below the ridgetop and even those that do pop up are flying too fast to stop for a look, except for the female that got away.

And the researchers did get the chance to use that third radio-tag. On January 5 wildlife officials in West Virginia contacted them about an immature male golden eagle that had been caught in a leghold trap for several days. The National Aviary’s Director of Veterinary Services and Animal Programs, Dr. Pilar Fish, said that “both sides of his leg were cut down to the bone from the trap, and the bone was crushed on one side, though not broken completely…He was dehydrated, stressed and infection had set in.” But after three months of expert rehabilitation, the bird was healthy enough to release, on March 22, where they had found him near Scherr, West Virginia.

In the meantime, I followed the other two eagles’ progress on The National Aviary’s website. The Thanksgiving eagle (called eagle 39) spent his winter mostly in southeastern West Virginia and the other eagle tagged on the Allegheny Front (eagle 40) wandered between southeastern West Virginia and eastern Kentucky. In March both migrated back through our area on their way to northern Quebec above tree line. Eagle 39 stayed above the western bulge of Labrador in Quebec and Eagle 40 at the edge of Ungava Bay. Both are probably defending territory, according to Katzner, because they have been staying put.

Eagle 41, the rehabbed bird, remained near his release site until May 10, and then he headed for Canada like the other two. He too ended up at the edge of Ungava Bay.

“It takes an eagle about five years to reach maturity and nobody is really sure what happens to eastern golden eagles in the time between when they are hatched and when they begin the breeding phase of their life,” Katzner said.

With the radio-tagging of three immature males, they’re beginning to find out. We will continue to follow the paths of eagles 39, 40, and 41 on The National Aviary website, and we’ll hope that this year one of the radio-tagged golden eagles will be caught on our talus slope.

golden eagle release
Mike releases one of the two eagles radio-tagged at the Allegheny Front Hawkwatch in November 2006 (photo: Todd Katzner)

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The Pennsylvania Game Commission has partnered with the National Aviary and the Powdermill Nature Reserve, which is the field station of the Carnegie Museum of Natural History in Pittsburgh, on the golden eagle study. They have given a $25,000 State Wildlife Grant that will add to the substantial funding by the National Aviary and the Carnegie Museum. Other researchers who are assisting in the study, officially titled, “Assessing Conservation Needs of Eastern Golden Eagles in Pennsylvania” are David Brandes of Lafayette College and Dan Ombalski of the Tussey Mountain Hawkwatch. A white paper recently released by the five researchers, Raptors and Wind Energy Development in the Central Appalachians: Where We Stand [PDF], says that “because of their demography, migration, and winter flight behavior, and high vulnerability to wind turbines, we consider Eastern Golden Eagles to be the eastern U.S. species at highest risk of population-scale impacts from wind energy development.”