Marcia Bonta

Looking for Winter Raptors

As citizen scientists become more numerous in the birding world, there is no end to the monitoring projects we can engage in. Take the WRS, for example, which stands for the Winter Raptor Survey. The brainchild of birder Greg Grove, it seems like the easiest of exercises–driving around a specific area in the middle of winter and counting and identifying winter raptors, including vultures.

Grove first launched the project in the winter of 2001 because he likes to use his birding skills to add to ornithological knowledge and is particularly interested in raptors. If the survey continues for many winters, he thinks it should be able to document population changes and the ages and sex composition of wintering open-country raptors–red-tailed hawks, American kestrels, northern harriers and rough-legged hawks–that can easily be seen from roads. By counting vultures–both black and turkey–in the survey, Grove hopes to add to growing evidence that wintering vultures have been expanding northward. He also encourages participants to report other raptors and their numbers as well as wintering owls and shrike invasions.

Since midwinter is a slow time for Pennsylvania birders, Grove figured they would be glad for an excuse to get out during the survey period in late January and early February. I know we were. When I first heard about the survey on the Pennsylvania Birds Listserv, I was eager to participate, but my husband Bruce and I wanted to go out with expert birders before doing our own survey. And what better ones to go out with than Greg Grove and fellow birder Dave Kyler on their survey of northern Huntingdon County?

So in early February on a sunny day with a light wind the four of us covered 30 slow miles over back roads, frequently jumping out of the car for closer looks at a bird or to scan the sky with our binoculars. Kyler nearly always spotted the birds first, and Grove was the designated driver. Bruce and I sat in the back of Grove’s Ford Explorer, trying to keep our hands and feet warm, because even though we were theoretically in a closed car, we were continually cranking the windows down for a better view or opening the doors and leaping out for a positive identification.

Our first bird was an adult red-tail sitting in a tree at the edge of a field. Next we identified the gray wings of a male American kestrel perched on top of one telephone pole and the rufous wings of a female kestrel on the line itself, followed by a pair of mature red-tails and another male kestrel.

As we drove along, Kyler gave us a running commentary on the bird life of the area, what Bruce later called Kyler’s “birding geography of place.”

“These are good fields for vesper and grasshopper sparrows in the spring,” he said of one place. Another area with white pine trees he referred to as “red-shouldered hawk territory. Red-shoulders like bottomlands. I’ve heard barred owls here too. Red-shoulders and barred owls go together.” We saw no red-shoulders there but later, in bottomlands, a red-shoulder flew out and across the road into the edge ofa small pine plantation and there it sat, giving all of us a good look at this “bonus” raptor.

We reached a lovely vista of fields and Tussey Mountain and jumped out for what at first looked like a turkey vulture. But we saw white where it shouldn’t have been, on the bird’s wings and tail, and the bird was huge. Out came the telescopes–Kyler’s and ours’–which gave us marvelous looks at an immature bald eagle sailing down the ridge.

“That’s another bonus,” Kyler said.

From that vantagepoint, we also spotted three black vultures.

“They have ridiculously short tails and flap more than turkey vultures,” Grove explained.

Later two more black vultures flew directly over the car. Seen from beneath, their outer wing tips are silver.

“They nest out here,” Kyler volunteered.

Later, we watched a female kestrel dive down into a field and fly up with prey in her talons and Kyler’s sharp eyes spotted still another bonus bird–a sharp-shinned hawk sitting on a tree branch at the edge of a patch of woods. In two and a half hours we tallied 12 red-tails, 7 kestrels, 10 black vultures, 1 bald eagle, 1 sharp-shin, and 1 red-shoulder. We also saw a large shrub in the middle of a field filled with bluebirds, two killdeer in another field, two northern flickers, a pileated woodpecker and the only bald cypress tree in Huntingdon County or maybe even in Pennsylvania.

As Kyler told it, “A farmer who fought in the Civil War brought the seeds back from the South and planted them beside a stream.” Sure enough, there was a large bald cypress, denizen of southern swamps, surrounded by its “knees,” growing along a stream with northern tree species.

To cap off our day, as Bruce and I drove home, we startled an immature red-tail sitting on our hollow road, eating a fox squirrel it had killed just seconds before. Unfortunately, we couldn’t count it. Still, it seemed like a good omen for our own survey.

Fired with enthusiasm, Bruce and I set out on a similar sunny, breezy day at 10:25 a.m. to cruise the back roads of Sinking Valley in Blair County. Since our Laurel Ridge Trail overlooks this bucolic valley, the winter raptors we see on our mountaintop farm are probably the same raptors that hunt in the valley.

Bruce had mapped out a 35-mile route and we expected to see the same number of raptors we had in northern Huntingdon County. But we didn’t. After two and a half frustrating hours we had tallied 4 red-tails and 2 kestrels. I was almost embarrassed to send in our total to Grove. But as he later wrote in his article for Pennsylvania Birds, “‘negative’ data is every bit as important as the ‘positive’ data from ‘raptor-rich’ counties in providing a complete picture of winter raptor and vulture distribution in Pennsylvania.”

However, I couldn’t help envying some of the other participants who posted their survey results on the Pennsylvania Bird Listserv. “We had an incredible day of hawk watching in Perry County,” Steve Hoffman, Director of Conservation for Audubon Pennsylvania, wrote. In six hours and over 105 miles, he and three other observers counted 50 red-tails, 14 kestrels, 58 turkey vultures, 4 black vultures, 2 bald eagles, and 2 Cooper’s hawks plus pipits and horned larks.

Bill Etter and Cameron Rutt in Bucks County took time to tally 10 lesser black-backed gulls and a north-bound mixed flock of black birds that was at least three miles long and stretched form horizon to horizon, in addition to respectable numbers of open-country raptors, including an immature northern harrier and both vultures.

Most remarkable of all was Scott Fisher’s two hours at Middle Creek Wildlife Management Area. Although his raptor list was relatively low–1 bald eagle, 2 red-tails, 8 turkey vultures, a kestrel and a Cooper’s hawk–his incidental birds were eye-popping–2000 tundra swans, 40,000 snow geese, 15,000 Canada geese, 2 American coots, 31 black ducks, 58 mallards, 6 northern pintails, 67 northern shovelers, 2 ruddy ducks, and 54 common mergansers!

The prize for grit and determination should probably go to Roger and Margaret Higbee of Indiana County. As they crested one hill on an ice-covered road, “our van began sliding backwards and did a 180-degree turn,” Margaret wrote. “Roger’s remarkable recovery kept us on the road, but neither of us wanted to try that hill again…(There weren’t any hawks up there anyway!!!)” In 102 miles they did see 33 red-tails, 7 kestrels, and 2 sharp-shins but no vultures.

But then only two vultures were seen in the whole northern and western Plateau section of Pennsylvania and they were black vultures in Lycoming County. As Dave Ferry reported, “The birds of the day had to be two black vultures…None of us had ever seen a black vulture in the Allegheny Plateau of northern Pennsylvania and I suppose it’s even more amazing considering it’s the middle of winter.”

Had they not been out there doing a WRS, those black vultures would have gone unrecorded. So too would have 170 more black vultures, 525 turkey vultures, 30 northern harriers, 1399 red-tails, 21 rough-legged hawks, and 392 kestrels in 56 of Pennsylvania’s 67 counties. Other bonus species were a merlin and 3 peregrine falcons in Allegheny County, 3 long-eared owls in Lawrence County, a short-eared owl in Mercer County, a snowy owl in Union County and a northern shrike in Lackawanna County.

Already Grove was detecting trends. Of the 1,140 red-tails that were aged, 91% were adults and of the 332 kestrels that were sexed, 60% were male, results that were similar to 2001. Rough-legged hawks had decreased from 2001 but continued to be concentrated in the northern counties and a few valleys in the central Ridge and Valley area, and harriers, despite their low numbers, continued to be widely distributed across Pennsylvania except for the High Plateau counties. Furthermore, despite the increase of vulture numbers in the Ridge and Valley, few vultures had moved into the northern and western sections of Pennsylvania despite the warm winter.

Will these trends continue? Only time and the help of dedicated birders will tell.

—-

You must have e-mail to participate in the WRS. Contact Greg Grove at gwg2 [at] psu [dot] edu.

February 1, 2003 Posted by Marcia Bonta | Birds, Citizen Science, Grasslands and Barrens, Pennsylvania Places, raptors, Winter | Leave a Comment