Overwintering Raptor Perch Locations and Types in Southwestern Oklahoma.

Abstract

Overwintering raptor species use a variety of hunting methods and perching types to search for prey in the agricultural landscape surrounding Weatherford, OK. Our primary objective was to identify species preferences for perch types (primarily a range of power transmission line pole sizes and materials, as well as pole density) and landscape context (tilled, non-tilled pasture, woodland, man-made structures other than power poles) near hunting locations. Two 48-km routes were sampled beginning in fall 2018, one north and one south of Weatherford, OK. Preliminary data show the following trends: American Kestrels (Falco sparverius) used wires between poles most often; Red-Tailed Hawks (Buteo jamaicensis) did not indicate a preference for perch type; juvenile Bald Eagles (Haliaeetus leucocephalus) were observed in tall trees; and Northern Harriers (Circus cyaneus) were only seen in flight. Additionally, all species used areas with little to no presence of man-made structures other than utility poles. Species’ differences in hunting methods and perch types may mitigate competition for common prey items (rodents) the winter, and the presence of utility poles may support increased abundances of some species’ populations beyond what would otherwise be possible. These preliminary data indicate that both American Kestrels and Red-tailed Hawks may benefit from the presence of utility poles and lines.