Response of Red-Tailed Hawks and Golden Eagles to Topographical Features, Weather, and Abundance of a Dominant Prey Species at the Altamont Pass Wind Resource Area, California: April 1999-December 2000

Technical Report · Sat Jun 01 00:00:00 UTC 2002

DOI:https://doi.org/10.2172/15000694· OSTI ID:15000694

Hoover, S

Studies have shown that raptors flying within the Altamont Pass WRA are vulnerable to fatal turbine collisions, possibly because of their specific foraging and flight behavior. Between June 1999 and June 2000, I conducted 346.5 hours of raptor observations within the Atlamont Pass WRA. Behavior was recorded in relation to characteristics of the topography (slope aspect, elevation, and inclination), the weather, and ground squirrel abundance, as determined by active burrow entrances. The most significant finding of this study revealed that red-tailed hawks and golden eagles flew more in strong winds than in weak winds, particularly along hillsides facing into prevailing winds (as opposed to hillsides shielded from the wind). This is likely a result of the birds' use of declivity currents for lift during flights. These results suggest that certain combinations of topography and weather produce wind currents that are sought out by foraging red-tailed hawks and golden eagles within the Altamont Pass WRA. To decrease raptor mortality, mitigation measures can be targeted to specific areas likely to attract foraging raptors because of their capacity to create particularly favorable wind currents.

• Research Organization: National Renewable Energy Lab., Golden, CO. (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC36-99GO10337
• OSTI ID: 15000694
• Report Number(s): NREL/SR-500-30868; XAT-9-29208-01
• Country of Publication: United States
• Language: English

Related Subjects

17 WIND ENERGY
ABUNDANCE
ALTAMONT PASS WIND AREA
AVIAN IMPACTS
BIRDS
CALIFORNIA
CAPACITY
INCLINATION
MITIGATION
MORTALITY
SQUIRRELS
TOPOGRAPHY
TURBINES
WEATHER
WIND ENERGY