Wednesday, October 23, 2002/lk
Two dark specks, barely visible to the naked eye, move across the crisp autumn sky. One swoops down toward a ridge, then the other follows and they are both lost to sight in the backdrop of trees on the south flank of Mount Hood.
“It’s a Cooper’s Hawk!” shouts a woman standing in a forest clearing more than a mile from the swooping birds, squinting through binoculars. “Two of them.”
A man nearby, also peering through binoculars, concurs and strolls over to a dry erase board propped against rocks. He wipes away “175” and scrawls “177” next to “Cooper’s Hawk.”
The two people, Sue Bruner and Eric Hallingstad, are in their seventh week manning the observation point at Bonney Butte, which lies at the south end of Surveyor’s Ridge. The ridge is known around Hood River mostly as a good mountain bike ride. But each year, from August through October, the air space above it is also the “hawk highway,” a regular route that raptors fly on their way south for the winter. Steady west winds create updrafts along the ridge that birds of prey ride to help them fly long distances while using little energy. With optimal conditions, a raptor can fly the length of Oregon in a day.
Raptors of all sorts — from many types of hawks and falcons to eagles, osprey and vultures — pass through here by the dozen each day during the migration season.
Bonney Butte is one of 16 observation points set up around the country — mostly in the West — by HawkWatch International, a non-profit organization based in Salt Lake City, Utah, that promotes education and research about raptor populations. In many places, including Bonney Butte, HawkWatch works in conjunction with the U.S. Forest Service to set up and maintain the stations.
“A big part of why we study raptors is that they give us a good indication of environmental health,” says Tillman Cavert, an educator and interpreter at Bonney Butte who explains raptor migration and HawkWatch issues to the birders and school groups who make their way to the remote butte on Mount Hood’s southeast flank. “They’re on top of the food chain, so whatever’s wrong, it’ll show up with them.”
This year, as for the past four to five years, what’s showing up is the widespread Western drought.
“They told us to expect lower migration numbers,” Hallingstad says. The dry erase board, on which Hallingstad and Bruner keep a running total of raptor sightings, has a column of last year’s tallies for comparison. Although there are still three weeks left in the migration season, the peak is well past and sightings of several raptors are significantly lower than last year. In 2001, for example, a total of 957 Sharp-shinned Hawks were seen here. So far this year, there have been only 381.
Despite lower numbers of some birds, the thrill of standing on the ridge at Bonney Butte, surrounded by flaming fall foliage, and spotting birds of prey heading south is palpable. Hallingstad, who has a biology degree and strings together seasonal jobs with non-profits, is in his second year as an observer at Bonney Butte.
“HawkWatch is pretty well known as being a good way to fill in between summer and winter work,” he says. The observers and bird banders, who camp just below the butte for the two-plus months of the migration season, get a small stipend for their work.
“It’s a great way to watch birds behave,” he adds. “You get to see some fun things up here that a lot of people don’t get to see.” Hallingstad and Bruner usually head up from camp to the observation point, where the only amenity is a waist-high windbreak of stacked rocks, at around 8 a.m.
“That’s bird time,” Bruner explains. “It’s 9 a.m. people time.” The observers and banders at the 16 HawkWatch stations use standard time in their observation notes to better coordinate their sightings for overall data study. From morning until 4 or 5 in the afternoon, when the birds start settling down for the night, Hallingstad and Bruner keep their eyes on the sky.
A half-mile away, Steve Page and Heather May are keeping their eyes on the sky, too — at least, on the small square of it they can see through the rectangular holes cut in the side of their blind. Page and May are running the banding station, a small wooden shack set among trees on a ridge above the observation point.
Every 30 seconds or so, Page and May pull on lines that run through the bottom of the shack and out to clearings in front of the blind. The lines are connected to pulleys, onto which live pigeons are fastened via leather harnesses. Page and May activate the pulleys to make the pigeons “fly” in order to attract birds of prey. When one does swoop down to go for a pigeon, the would-be meal is yanked away and, with the help of another pulley system, a net catches the raptor. If that fails, the birds often get their claws tangled in the vertical “miss” nets on either side of the clearing.
Page or May then go out and retrieve the bird and bring it back to the blind so they can record measurements and fasten a band around its leg for tracking purposes before setting it free.
Along with two pigeons used as bait, a starling is connected to a third pulley for the smaller birds of prey.
“The pigeons are rotated every two hours,” May says. A cage behind the blind contains a dozen cooing pigeons. The pigeons are raised and kept by Forest Service raptor biologist Rich Thurman, who trained Page and May in August for their capturing and banding duties and spends several days a week helping at the site.
Like the observers, the banders spend long days watching the sky. A propane space heater emits a little warmth in the shack, but Page and May are bundled in wool and down, with winter hats pulled down low.
They usually catch about nine raptors a day, Page says. Their record is 22. It depends on the wind and weather conditions.
“With a good west wind, the (birds) will usually fly right over us,” Page says. If the wind is light, or from the east, they’re often spread out over a wider area and are harder to lure to the banding station.
After a slow morning, with only one Sharp-shinned Hawk caught and banded and another that bounced out of the miss net and flew off, Page yells, “Bird!”
All goes quiet, the only sound that of the pulleys as Page and May work the lines. Suddenly there’s a whirl of feathers in front of the blind and the pigeon is whisked to safety. The bird escapes the main net, but its talons get caught in the miss net.
“It’s a female Sharpie,” she says — a Sharp-shinned Hawk.
Inside the blind, she tucks the bird into a can with the ends removed. This lets her do measurements without getting pecked at. Eventually, though, she pulls the bird out to measure its keel — breastbone — to see how much fat it has, and its crop, where it stores food.
“It’s kind of sticking out,” she says, prodding gently at the bird’s neck. “It’s about three-quarters full.” The hawk is testy, twisting its head to snap at May every few seconds. Its yellow eyes dart around the shack as May completes her measurements. After fastening a metal band on the bird’s leg, May takes the hawk outside and lets go. The Sharpie flies straight up, then darts through the tree tops and disappears.
With luck, the hawk will survive several more migration seasons, and when it dies, someone will recover the metal band and turn it in. HawkWatch could then count it among the 10 percent of banded birds that are recovered, and the organization would be able to infer things about its life and migration routes by tracing the band back Bonney Butte.
Back at the observation point, a small crowd has gathered to see a Merlin and a Cooper’s Hawk that were caught at the banding station around mid-afternoon. Cavert hiked up and brought them down in cans to show to the visitors that didn’t make the hike to the blind.
Cavert gently pulls the Merlin out and holds it up for everyone to see. The falcon is rare, but is seen at Bonney Butte more than at most HawkWatch stations. After a minute, Cavert opens his hand and the Merlin flies off.
He pulls the Cooper’s Hawk from its can and everyone gasps at seeing such a large, wild bird up close.
“This is an adult female,” Cavert says. “It’s a good sized bird.” Her tail and wings have distinct dark bands across them. She nips at Cavert’s hand.
“She’s getting kind of antsy,” he says. He walks a few steps away from the visitors, opens his hand and the hawk flies away, swooping toward the west briefly before turning south and disappearing into the afternoon sky.
The Bonney Butte HawkWatch site is open to the public. A four-wheel drive vehicle is recommended for the rough road. From the parking area, it’s about a half-mile hike to the observation ridge.
The site is located off Forest Road 48, which turns off of Highway 35 at the White River East Snow Park. Further information and directions are available at the U.S. Forest Service Hood River Ranger Station, 6780 Highway 35 in Mt. Hood.