Bridger Mountains Raptor Migration

Bridger Mountains Raptor Migration – Bozeman

Friday, September 05, 2014 – Friday, October 31, 2014

Hawk-Bozeman-Montana-Roadtrekin.comHawk Watch International (HWI) began full-season, fall migration counts at this site in southwestern Montana in 1991, with standardized, single-site counts commencing in 1992. This ongoing effort monitors long-term trends in populations of raptors using this northern portion of the Rocky Mountain Flyway.

More than twenty years ago, Fred Tilly discovered the Bridger Range to be an important fall flyway for raptors. He conducted limited migration counts at the site in 1979, 1980, and 1982 to set the stage for HWI beginning standardized counts in the 1990s.

The count, organized by Montana Audubon since 2010, now occurs from a helicopter platform located atop the ridge above Bridger Bowl Ski Area, about 25 miles northeast of Bozeman, Montana.

The flyway is noted for the largest concentration of Golden Eagles in the lower 48 states, with peak eagle activity (sometimes more than 200 eagles/day) in mid-October. Golden Eagle counts typically range from 1,200-1,900 birds per season.

Up to 1,500 migrants of 17 additional species also may be seen each season, with Sharp-shinned Hawks, Cooper’s Hawks, Red-tailed Hawks, Bald Eagles, and American Kestrels among the most commonly seen species. The project runs from about 27 August to 31 October each year.

In 2013, HWI conducted or co-sponsored 8 long-term standardized migration counts in 7 states. The data from Bridger Mountain is part of a North American-wide long term analysis that HawkWatch conducts with partner organizations Hawk Mountain and HMANA.

The information gathered in these studies enables us to better understand the life histories, ecology, status, and conservation needs of raptor populations in North America. Because raptors are top-level predators, occupy large home ranges, inhabit most ecosystems, and are sensitive to environmental contamination and other human disturbances, they serve as important biological indicators of ecosystem health.

Moreover, due to the remoteness and widespread distribution of most raptor populations, migration counts likely represent the most cost-effective and efficient method for monitoring the regional status and trends of multiple raptor species.

In addition to gathering important scientific data, the Bridger Mountains project provides opportunities for the public to learn about the ecology and conservation needs of raptors through on-site environmental interpretation for visitors. Education is the key to long-term success in securing public understanding and action on behalf of raptors and the ecosystems upon which we all rely.

Public participation is FREE! Groups and children are welcome. Please call Montana Audubon at 406.443.3949 or visit for more information.

The Bridger Raptor Festival is an annual event held in and around Bozeman, Montana. The festival, which is free to the public, centers around a raptor migration count of the largest known Golden Eagle migration in the United States which takes place at the Bridger Bowl ski area in the Gallatin National Forest just north of Bozeman. Other activities include wildlife films, nature walks and talks, education and entertainment programs for people of all ages.

For more information, visit

Source:  Virtual Montana