“I think that the Bald Eagle Ridge is the single best place in Pennsylvania to observe golden eagles,” Mike Lanzone told us. He was talking about our mountain, which is the westernmost ridge in Pennsylvania’s ridge and valley province.
Lanzone is the Assistant Field Ornithology Projects Coordinator for the Powdermill Avian Research Center. He, along with his wife Trish Miller, who is GIS coordinator for the Powdermill Nature Reserve near Ligonier, and Dr. Todd Katzner, Director of Conservation and Field Research at The National Aviary in Pittsburgh, were interested in live-trapping and radio-tagging golden eagles on our property.
Those eagles would be part of a larger study to determine the impacts of wind farms, which have been proposed for our ridge and many others in central Pennsylvania, on golden eagle migration both in the spring, when they favor nearby Tussey Mountain, and in the autumn, when the Bald Eagle Ridge and the Allegheny Front are heavily used. They also hoped to identify “critical migration bottlenecks where turbine development should proceed with caution,” according to Katzner.
In addition, so little is known about the behavior of eastern golden eagles, for instance, where and how individual eastern golden eagles migrate through the Appalachian flyway, that radio-tagged eagles would help to resolve those questions.
Golden eagles are a holarctic species that lives throughout Europe, Asia, and north Africa. Of the six named subspecies, only one, Aquila chrysaetos canadensis, has been classified for all of North America. Most of the research on golden eagles in North America has been done in the West, although eager raptor watchers have been observing and counting these magnificent dark brown birds with their seven-foot wingspans for decades at such well-known places as Hawk Mountain and Waggoner’s Gap, both on the easternmost ridge in the ridge and valley province, and more recently on other ridges and on the Allegheny Front.
Year by year the numbers of eastern golden eagles have inched upward, and last autumn was no exception. Hawk Mountain tallied their highest number ever — 171 — and Waggoner’s Gap, long identified as the place to view migrating golden eagles in the fall, counted 269.
We were confident, when we first met with Lanzone, Katzner, and Robert Mulvihill, the Field Ornithology Projects Coordinator for Powdermill, on a balmy, late September day, that golden eagles would be migrating along our mountaintop the first two weeks in November as they always had. The scientists were confident that those birds would come zooming down Bald Eagle Ridge on the northwest winds, see our open First Field, and fly toward it. After all, there aren’t many fields on top of the ridge, and this is a bird that likes open vistas for hunting and nesting.
Katzner and Lanzone planned to build a blind at the edge of our Norway spruce grove and asked my husband Bruce to cut the field, which is really an overground meadow, in front of the grove. Bruce did his work with our tractor and brush hog, and the scientists arrived on the first of November to do theirs. It took them two days of hard work to set up the blind and the two spring-loaded bow net traps. The finished six-by-eight-foot blind, which they hauled up in sections in their pickup truck, looked as good or better than ones we have seen at wildlife refuges. They painted its plywood sides brown and green and had designed a long, narrow, tinted window in the front for their observation with flaps that would be lowered when they spotted a bird heading for the bait. They also designed two small side windows and four small windows on the roof for observing visitors like me. Lastly, they attached spruce boughs on its front and sides and draped them over the roof. Even I had a hard time spotting the blind tucked in among the spruces.
Then they prepared the field and set up their two bow nets. Lanzone used an electric lawnmower to cut the grass closer around the nets while Katzner hand dug and removed all the black locust snags and roots and other possible woody debris on which the nets might catch. They also painted a camouflage brown the shiny tubes that supported the net and the white surgical tubes that they buried in the ground and covered with dried grass, because it was imperative that the scene look as natural as possible. The buried tubes were threaded with rope attached to the net and were controlled by the ornithologists through small holes in the blind.
By then I was anxious. Already four days were gone in those critical first two November weeks. On the other hand, the weather was either misty and still or beautiful and still. Where were the cold, northwest winds of November?
Then came the ninth of the month and Lanzone, Miller, and seven-month-old Phoebe. As they unloaded their car, two golden eagles flew past. Golden eagles, Mike told me, fly earlier in the morning than most raptors. Later, two more goldens flew by, but instead of flying toward our field, they popped up from behind the ridge, as they often do when I’m counting raptors. But the researchers did catch and band one red-tailed hawk as practice before I arrived at the blind.
We sat on overturned plastic buckets or folding chairs and Lanzone and Miller never stopped scanning the horizon for eagles. I was impressed with their dedication and the incredible patience of baby Phoebe who played on a blanket with toys or obligingly nursed or slept.
Nothing happened during my visit so I carefully exited the blind via the back door, which led into the depths of the spruce grove, and then walked home through the forest so that I was hidden from any potential eagles.
As I crossed the small, powerline right-of-way near our home, I noticed a large, dark bird hovering and flying slowly above the field. A red-tail chasing it looked small against what was an adult golden eagle. I watched until the eagle circled high and flew across the ridge. Apparently, it then dropped below the ridgetop because Miller and Lanzone never saw it.Clear, warm, and beautiful; warm and raining; overcast and still. Would Indian summer never end? Lanzone and Miller (and baby Phoebe) came off and on, and I shared time in the blind with them, but we all agreed that never had there been such bad November weather for the golden eagle flight. By the third week in November we had had not one good, windy day.
At last, on November 17, the wind picked up, providing the updrafts and thermals the golden eagles needed to speed them southward. Katzner and Lanzone arrived shortly after noon. Instead of golden eagles, though, the red-tails were flying. First one immature stooped on the bait, but the bow net caught on shards of goldenrod stems when they sprang it. The immature flew into a tree and watched as another immature landed across from it.
Suddenly a mature red-tail zeroed in, grabbed the bait, and “blam,” that net sprang over the red-tail. The men raced out of the blind and untangled the hawk. They banded that one and a second red-tail they caught later, they told me back at the house.
What encouraged them was that they had spotted the red-tails far down the ridge. Then the red-tails seemed to disappear. But both had popped up above the ridge and turned sharply left to fly over the top of the field and grab the bait.
“A good sign,” Katzner said, that maybe the eagles would do the same.
Hopeful that the windy weather would hold, they camped out overnight in the blind. But by morning it was once again back to still and overcast. I joined them in the blind in the afternoon, and all we saw was one sharp-shinned hawk that tried twice to grab the bait and missed and a Cooper’s hawk that did likewise.
Lanzone showed up on the 20th even though it was still and overcast. He had heard that 35 golden eagles had flown down Franklin Mountain in New York state the previous day and expected a flight along our ridge. He did spot two golden eagles, but they flew over the ridge and down into the valley. He also counted 1500 tundra swans, 200 Bonaparte’s gulls, and several ring-billed and herring gulls. At least something was moving. And Lanzone, who has been counting birds and live-trapping raptors since he was a boy of nine in New York state, couldn’t resist tallying whatever birds he saw during his long hours in the blind.
Thanksgiving dawned rainy and misty. Even though the trio had talked about coming here, I didn’t expect them. Surely they were home enjoying the holiday and forgetting about golden eagles just as we were.
Wrong! Three days later I received an email from Katzner. They had caught two immatures — a four-year-old male golden eagle on Thanksgiving and a two-year-old male two days later at their other blind near Central City beneath the Allegheny Front Hawkwatch. The day before Thanksgiving, Katzner wrote, “was about the most frustrating eagle trapping day that we’d had. We sat in our blind under the Allegheny Front Hawkwatch and watched 39 [golden] eagles fly by us. A few glanced at our bait, but none came in anywhere close to the traps we’d set. Thanksgiving Day turned out to be a different kind of day.” Indeed it was.
Trish Miller and Mike Lanzone with one of the immature goldens they trapped at the Allegheny Front Hawkwatch last year
While I was happy for the researchers, I was sad that no golden eagle had been tagged here. Miller had actually sprung the trap, just as she had done the previous year when most knowledgeable ornithologists had thought it impossible to capture and radio-tag eastern golden eagles.
Once they banded the birds and took their measurements, they attached to each one’s back a satellite telemetry device using a nonabrasive harness made of Teflon ribbon. It contained a solar panel and weighed 70 grams, a weight that didn’t seem to bother the eagles.
In the meantime, I hung out in the blind by myself, vainly watching for any raptor movement at all during the last dreary days of November. By then rifle season had begun, and our hunters had agreed to give First Field and its environs a wide berth. They too hoped that the researchers would score.
Part 2 continues on December 1.
The last photo is by Todd Katzner; all others are by Dave Bonta.
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