Grand Canyon Raptor Migration Project
The Grand Canyon Raptor Migration Project in Arizona is an ongoing effort to monitor long-term trends in populations of raptors using the southern portion of the Intermountain Flyway. The flight through this region is one of the largest concentrations of migrating raptors known in the western U.S. and Canada. To date, HWI observers have recorded 19 species of migratory raptors at two count sites along the south rim of the canyon, with combined counts typically ranging between 10,000 and 12,000 migrants per season, although numbers dropped off significantly in 2004 and 2005, probably due to a combination drought effects and shifting flight lines. Chuck LaRue discovered the flyway in 1987 and Christie Van Cleve conducted exploratory counts at points along the south rim in 1989 and 1990. HWI initiated standardized counts of the autumn raptor migration through this region at Lipan Point in 1991, and began standardized monitoring at Yaki Point in 1997. Counts at both sites run from 27 August through 5 November each year.
In 2008, HWI conducted or co-sponsored 14 long-term standardized migration counts in 10 states and Veracruz, Mexico. The primary objective of these efforts is to track long-term population trends of diurnal raptors in western North America and around the Gulf of Mexico. The information gathered enables us to better understand the life histories, ecology, status, and conservation needs of raptor populations in North America. Raptors feed atop food pyramids, inhabit most ecosystems, occupy large home ranges, and are sensitive to environmental contamination and other human disturbances. Therefore, 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 methods for monitoring the regional status and trends of multiple raptor species.
These migration studies also offer unique opportunities for the public to learn about raptors and the natural environment, and providing such opportunities is another important component of HWI's mission. 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. Accordingly, since 1995 the Grand Canyon field crew has included trained educators dedicated to conducting environmental education programs at the sites and facilitating interactions between visitors and the field biologists. With about 5 million people visiting the park each year and easy accessibility, the Grand Canyon sites offer excellent opportunities for public outreach and education about the ecology and conservation needs of raptors and the Grand Canyon ecosystem. Located in Grand Canyon National Park, the raptor migration is a popular attraction; many of the shuttle bus drivers in the park are hawk enthusiasts and often come to the sites to get daily updates on the migration. Public participation is welcomed at all HWI migration sites. See the Grand Canyon Guide for regularly scheduled programs, or look for the educators on duty at both sites.