Central Valley winter raptor survey (2007-2010): Perch Selection and the Influence of Weather on Raptor Behavior
DOI:
https://doi.org/10.64555/bvkzys02Keywords:
behavior, non-breeding, Turkey Vulture, White-tailed Kite, Bald Eagle, Golden Eagle, Northen Harrier, Cooper's Hawk, Sharp-shinned Hawk, Red-shouldered Hawk, Red-tailed Hawk, Ferruginous Hawk, Rough-legged Hawk, American Kestrel, Merlin, Peregrine Falcon, Prairie Falcon, Loggerhead ShrikeAbstract
We analyzed the perch type preferences for wintering open county raptors in the Central Valley. Among the Buteos, Red-tailed (Buteo jamaicensis) and Red-shouldered (Buteo lineatus) Hawks preferred taller perches such as trees or utility poles, while Ferruginous (Buteo regalis) and Rough-legged (Buteo lagopus) Hawks usually perched on fences or on the ground. White-tailed Kites (Elanus leucurus) were the most likely to use trees for perches, and utility wires were favored by American Kestrels (Falco sparverius) and Loggerhead Shrikes (Lanius ludovicianus). We also examined the effect of wind and cloud cover on the likelihood of finding a species perched or in flight. Both Red-tailed Hawks and American Kestrels were more likely to be observed in flight as the wind speed increased, and Turkey Vultures were more likely to be in flight on sunny rather than cloudy days.
