HawkWatch fall migration crew members Paula Eberle, Erin Barry and Elly McManus perch along the rocky, windy spine of Chelan Ridge, bundled in parkas and sleeping bags, with binoculars in hand, notebook computers balanced in their laps. A great horned owl decoy attracts migrating raptors to swing low for a closer look.
“They try to attack the decoys because owls are big nest predators,” Eberle said. “It’s the birds’ instinct to defend their chicks.” HawkWatch International collects raptor migration data across seven sites in the Western U.S. They began 35 years ago and have included data from the Chelan Ridge site for the last 22 years. Biologists return to the exact same rock on Chelan Ridge every year from September through October to collect data from a consistent location and date range, Barry said.
This year, five biologists are collecting data at the Chelan Ridge HawkWatch site. Eberle, Barry, and McManus watch the skies from the lookout rock, and Zoe Bonerbo and crew lead Nicole Richardson manage the banding station.
The Chelan Ridge HawkWatch site is located on the Okanogan-Wenatchee National Forest, along Forest Service Road 8020, also known as Cooper Mountain Road, which climbs out of the valley at Black Canyon. A HawkWatch International recording board marks the small parking area and is updated daily with counts and banding totals.
A trailhead sign marks the beginning of the trail to the lookout area. The .75-mile trail gently climbs northward through shrub-steppe with expansive views of surrounding ridgelines and Lake Chelan to the west. Interpretive signs detail flora and wildlife habitat along the trail. This HawkWatch International site is a partnership with the Okanogan-Wenatchee National Forest and other groups, including the Community Foundation of North Central Washington, North Central Washington Audubon Society and Kittitas Audubon Society.
Biologists record the weather every hour from their perch on the rocky spine, noting barometer pressure, temperature, wind speed, and wind direction. On this day, Eberle called out readings while McManus recorded weather data. Hawks migrate when wind conditions are most favorable, traveling on wind currents blowing in their intended direction to conserve energy, McManus said. On a morning when the winds blew northward, the team saw just two birds per hour. Winds shifted later that afternoon to a north wind, flowing in a southern direction. The team stated they saw nine raptors an hour as the birds took advantage of the favorable wind direction.
Fall migration is a prime opportunity to observe the overall population numbers and health of raptors. The long-term data collected from HawkWatch sites help identify trends over time and are used by wildlife managers to inform conservation plans.
When a raptor is sighted, the three biologists confirm the species and record the count. This data is used to track group trends and migration numbers. To date, red-tailed hawks and sharp-shinned hawks are the most commonly sighted birds, followed by Cooper’s hawk, northern harrier, turkey vultures, accipiter species, and merlins.
The birds have different destinations. Species that live furthest north, like rough-legged hawks, only go as far south as California, but the Swainson’s hawk travels all the way from Canada to Argentina. “It’s insane. They go so far and stay there for a little while — and then come back,” McManus said.
Barry explained that more detailed data is collected at the banding station on migrating raptors age, health, body composition, and crop contents. Daily counts, hourly data, and weather specific to the Chelan Ridge site can be viewed on https://hawkwatch.org/chelan.
Not all raptors viewed from Chelan Ridge are migrating south. McManus noted that sharpies and kestrels are year-round residents that may be flying around to protect their territory. Researchers closely observe hawk behavior to determine if the bird is truly migrating. To be classified as a migrating bird, the bird must be heading south, flying quickly and in a straight line.
Migrating hawks rest at night in parks and urban areas. They are not active during inclement weather and may try to make up for lost time the day after a storm. In fact, the Chelan Ridge biologists recorded the highest number of migrating hawks the day after a heavy rain. On September 11, 57 migrating raptors from 12 different species were recorded. According to https://hawkwatch.org/chelan, “counts typically range between 2,000-3,000 migrants of up to 17 species per season.”
Research operations were suspended in 2020 due to COVID-19 precautions at five sites, including Chelan Ridge. Teams live and work closely together in remote wilderness areas for six days a week, up to nine hours a day. The health risk for COVID-19 infection was too great prior to the availability of a vaccine.
“The organization lost a year of data,” said Barry, and McManus said reduced funding from non-profits who also experienced a decline in donations and resources.
Now that vaccines for COVID-19 are widely available, all seven sites are open for researchers and visitors. Crews are required to be vaccinated for COVID-19. Guidelines for visitors are posted on HawkWatch.org at https://hawkwatch.org/blog/item/1256-migration-is-on. Visitors are asked to consider their own vaccination status and not put unvaccinated children at risk, as the site receives groups of young student visitors.
On Sept. 30, HawkWatch International kicks off a month of celebration of “35 Years and Counting,” a five-week virtual program. The series includes lectures and virtual site visits, all enjoyed from the comfort of home. Register for events at https://hawkwatch.org/.
HawkWatch International is funded through donations and grants. To learn more about HawkWatch activities at Chelan Ridge, join the Facebook group “Friends of Chelan Ridge HawkWatch” and follow the HawkWatch Facebook page. The website https://hawkwatch.org/ is a detailed resource for visitor guidelines, detailed directions, blogs, bird counts to date, and ways to support HawkWatch International, including by “adopting” banded raptors.