Radio-Equipped Prairie Falcons Take to the Sky
By: Doug Bell, PhD, Wildlife Program Manager
Sara Snyder, Raptor Intern with the EBRPD, supported by a grant from the Southern Alameda County Birds of Prey Reserve Foundation and Brian Latta, Biologist with the SCPBRG, about to release a prairie falcon that has been outfitted with a radio transmitter.
The East Bay Regional Park District with financial support from Save Mount Diablo and others is currently conducting a three-year study on prairie falcons. Seven falcons were fitted with backpack radio transmitters with the goal of using data collected on their foraging patterns to promote habitat conservation planning. Biologists at the Park District track where and how far these falcons travel. The results could provide a telltale sign of the environmental health of East Bay grasslands and tag which lands are most vital to protect in the future.
Prairie falcons (Falco mexicanus) are medium-sized falcons found in western North America. They have been documented in the dryer places of the East Bay for thousands of years. In scientific terms, the prairie falcon is known as an indicator species. Where it hunts indicates how healthy the area is in terms of other species typically found there such as ground squirrels, kit fox, golden eagles, burrowing owls, California red-legged frogs and California tiger salamanders.
While the District will continue collecting data for two or more seasons, the preliminary findings show that falcons are wider ranging and travel greater distances from the nest when foraging. A similar survey conducted at Pinnacles National Monument in central California concurred and found that prairie falcons sometimes travel up to 16 miles from their nests. Another interesting finding is that public lands which are grazed appear to offer prairie falcons excellent foraging opportunities in the form of abundant ground squirrels. Finally it seems clear that the falcons avoid developed areas.
Douglas Bell is the Park District's Wildlife Program Manager. He received a PhD in Zoology from UC Berkeley, and was a Postdoctoral Associate at the California Academy of Sciences. Just prior to joining the Park District in 2005, Dr. Bell was an Associate Professor of Biology at California State University Sacramento. He has a long interest in raptor ecology and conservation issues.