UNEXPECTED MOVEMENTS AND MIGRATION BY BREEDING PEREGRINE FALCONS (FALCO PEREGRINUS) IN PLUMAS COUNTY, CALIFORNIA

Colin P Dillingham; USDA Forest Service; cdillingham@fs.fed.us; Jeff W Kidd, Scott E Thomas, Elizabeth F Morata

From 2016 to 2017, we attached five global positioning system (GPS) transmitters to peregrine falcons (Falco peregrinus) in a previously unstudied population in the Sierra Nevada of Plumas County, California. This pilot study was intended to help the U.S. Forest Service better understand movement ecology and use of various forest habitats, including those areas that were subject to a devastating 65,000-acre forest fire in 2007. Breeding adult falcons were captured near three different cliff nest sites using a dho-gaza with a live great horned owl (Bubo viginianus) as the lure. Trapping was conducted in July of each year when adults were feeding young that were at least four weeks of age. Three solar-powered satellite and two cellular-based GPS transmitters were attached in the backpack position. Tracking data suggest adults travel up to 30 kilometers in each direction to forage during the chick-feeding stage. During late summer and early fall, adult falcons moved to lower elevations in the Sacramento Valley to winter while others migrated to downtown Los Angeles and as far as southern Mexico.

Ecology and Conservation of Birds I