Raptor Enrapture

Raptor EnraptureThe joys of watching birds of prey. By Becky Lomax

This story is featured in Montana Outdoors
July–August 2004

Along Blowout Mountain, a black dot soars. Through binoculars, I squint to find a bit of color that would help me identify the bird, but from this distance, it’s impossible. Beside me in the blind, a researcher glances for a few seconds at the distant speck. “It’s a goshawk,” he announces casually. While I strain to see markings to indicate the species, the northern goshawk rides gusts along the Rocky Mountain Front ridgelines in our direction.

Raptors travel along the Front on their annual migratory patterns, trekking north to breeding grounds early each spring and south to wintering ranges in early autumn. During these seasonal pilgrimages, many birds of prey fly near Rogers Pass, along the Continental Divide about halfway between Helena and Great Falls. It’s a remote area of rugged terrain and relentless wind, where broad grasslands are interspersed with stunted lodgepole pine and gnarled subalpine fir thickets.

From September through mid-November, Rob Domenech spends long days in this weather-beaten terrain counting, capturing, and banding raptors. Founder of the Raptor View Research Institute in Missoula, Domenech today is working with the California-based Wildlife Research Institute, Inc., which sponsors migratory eagle studies in Califor-nia, Montana, and New Mexico. To track raptor migrations, populations, and survival, he leads a team of researchers and volunteers who lure raptors to net traps for banding. (When the banded birds eventually die, people who find the carcasses are urged to report the band number to a national bird banding laboratory, which uses the information to monitor populations.)

Rogers Pass is one of the nation’s top raptor viewing and capturing sites, especially for golden eagles. “In one season, we’ve banded more golden eagles than all banding stations in North America combined,” says Domenech. Hawks, falcons, and bald eagles also migrate along this flyway. During the fall 2003 banding season, nearly 1,900 raptors crossed Domenech’s study site, with a single-day high of nearly 200 birds. On an average day during the fall migration, 41 raptors fly over Rogers Pass. Sharp-shinned, red-tailed, and rough-legged hawks comprise 25 percent of the migrants. Other visitors include Cooper’s hawks, northern goshawks, kestrels, and northern harriers.

What attracts birds of prey to this remote site? Westerly winds and strong thermals drive the raptors along the Rocky Mountain Front toward Rogers Pass. With ground squirrels, mice, and jackrabbits (favored by golden eagles) romping through plush grasslands abutting the Front, the birds have plenty of opportunities to refuel along their trek. The raptors follow lengthy migration routes along the Front from as far north as the Arctic Circle all the way to South America.

As my husband and I near the banding site, we alert Domenech of our approach via a small two-way radio. It’s all very secretive, as a volunteer assistant leads us on a faint trail through a tangle of subalpine fir. The hidden route, she explains, veers away from open fields where we might disturb incoming raptors. I knew our presence might startle a nearby bird, but I didn’t expect it to affect an eagle’s flight path nearly 2 miles away. I later learn from Domenech that these birds have eyesight more exceptional than I ever imagined.

Once at the site, we enter the viewing blind—a 4- by 8-foot plywood box covered with fir trees—and begin looking for raptors. To my untrained eye, one flying bird looks like another, a brown spot evolving into flapping color as it nears. Domenech assures me my difficulty in identifying raptors is not an eyesight defect but a matter of not seeing shape and flight patterns.

I grab a silhouette diagram of raptors in flight to help me identify incoming birds. Body, wing, and tail shapes are the easiest ways to identify flying raptors, Domenech explains. Falcons have pointed wings and tails used for spectacular swoops and wing-tucking dives. Broad-winged hawks (buteos), such as the red-tailed, rough-legged, and ferruginous, have long, broad wings and tails for gliding and kiting. Accipiters, like the northern goshawk, Cooper’s, and sharp-shinned, are woodland hawks with narrow, falconlike tails and broad wings that allow them to maneuver through trees. Much larger than the other raptors are the bald and golden eagles.

As the day progresses, I learn to distinguish flight patterns. Because goldens mi-grate up to 200 miles in one day using updrafts, their flight patterns become obvious: long, gliding rides alternating with big, lumbering flaps across peak tops. With 7-foot wingspans, the birds are unable to negotiate low flights through trees. When we see a raptor pop up out of thick vegetation, it’s usually an accipiter. And quick, short flaps are the sign of an incoming red-tailed hawk. We can tell golden eagles from immature bald eagles by wing shape and movement: A golden’s dihedrally (shallow V) shaped wings flap less often than the bald’s flatter, wider wings.

As a golden eagle glides directly toward us, even I am able to recognize its telltale faded coloration, brown with light patches around the neck nape and subtle tail banding. On a high pole above the treetops, Domenech has placed a horned owl decoy. It is intended to lure eagles, which, drawing nearer, see the moving bait in the banding trap below. When they land to check out the flapping, tethered pigeon, a 4-foot diameter net on a spring system snaps over the raptors. To see the approaching eagle better at this close range, I lower my binoculars. The bird abruptly changes course, its eye detecting my tiny movement through the 2-inch slit in the blind.

The researchers in the blind sigh.
In addition to movement, bright colors alert raptors to the presence of humans. As I look at the researchers, their muted browns, greens, blues, and grays match environmental hues, a cue for dress codes when birding. No wonder someone shoved my husband’s vivid red pack deep under low tree branches.

Gaudy hues aren’t the only things that bother raptors. Most don’t like it when people get too close. Goldens, for example, are highly intolerant of humans. “You can almost picnic beneath an osprey, and the osprey won’t care,” Domenech tells me, “but golden eagles will leave if they suspect human presence.” To avoid stressing raptors, viewers should use a spotting scope or binoculars and view from a distance. “You know you are too close if a bird vocalizes,” Domenech adds.

In September, during fall migration, a few goldens trickle over Rogers Pass each day. At the same time, red-tailed hawk migrants arrive along with sharp-shinned and Cooper’s hawks. American kestrels also join the early-season fliers. As goldens reach high numbers in the third week of October, rough-legged hawks, whose treks start high in the northern arctic, also peak.

On warm fall days, birds may sense no reason to move south, as prey is often active then. Mild weather usually brings good hunting, says Domenech, so sightings are rarer then. But on rough weather days, when cool air masses push south into Montana, the raptors start migrating again. Though howling winds and frosty conditions make it tough on the raptor watchers, the price of a few shivers is usually worth the high number of raptors seen.

Rogers Pass is next to one of 46 statewide routes that FWP biologists follow each spring during their annual raptor survey. One of the nation’s longest-running raptor studies, the 28-year-old survey shows trends in different raptor populations. “During that period, we’ve generally observed raptor numbers increasing,” says Ryan Rauscher, FWP nongame wildlife biologist in Glasgow who coordinates the survey.

In late spring, most raptors settle into breeding areas. Look for them in treetops or cliff nests, but be careful not to venture too near. “Raptors laying eggs are very susceptible to disturbance,” says Rauscher. “As a rule of thumb, a quarter-mile is plenty close.” In midsummer, look for fledglings in the nest and increased hunting activity by adults before the migration’s onset.

To see birds of prey in the Rogers Pass area, follow U.S. Highway 287 north from Wolf Creek. The next 21 miles run along the FWP survey route. At Bowman’s Corner, turn west onto Montana Highway 200 toward Rogers Pass. A few miles past the Stearns-Augusta road crossing, a marked pullout on the road’s north side denotes the Rocky Mountain Front Eagle Migration Area with an “Eagle Watch” sign. You can monitor migrating raptors with scopes and binoculars there and at any unmarked pullouts between there and Rogers Pass.

Though the spring migration in March and April provides great raptor watching, deep snows make it tough to reach higher elevations, restricting viewers to lower roadside pullouts. In early fall you can watch from the pullouts or hike the Continental Divide Trail north or south from Rogers Pass. If you plan on walking off-road in the Rogers Pass area, don’t bother or disrupt researchers trapping and banding raptors. Walk discreetly and quietly and move through the trees rather than out in the open, where raptors can spot you from far away.

Late in the afternoon, after viewing dozens of raptors overhead, we watch as Domenech traps and bands a northern harrier. This hawklike bird, with its telltale white rump patch, is usually seen cruising just a few feet over grasslands and dry marshes searching for voles. The harrier turns its comical, owl-like face toward us before a volunteer releases the bird into the sky under the setting sun’s tawny glow. Our eyes follow the raptor as it climbs a thermal high above the Continental Divide, disappearing on its southerly journey.Bear bullet

Becky Lomax is a freelance writer in Whitefish.