Distribution of wintering Ferruginous Hawks (Buteo regalis) in relation to black-tailed prairie dog (Cynomys ludovicianus) colonies in southern New Mexico and northern Chihuahua

We studied winter habitat use of Ferruginous Hawks (Buteo regalis) from November 1999-February 2000 in southern New Mexico and northern Mexico by comparing vegetation in New Mexico among three potential hawk habitat types; occupied black-tailed prairie dog (Cynomys ludovicianus) colonies (N = 13), areas without prairie dogs that had historical records of occurrence (N = 7), and general grassland areas (N = 8). In Mexico, we recorded habitat use of hawks observed during driving surveys. Overall, 20 of 22 Ferruginous Hawks observed throughout the study were associated with occupied black-tailed prairie dog colonies. In New Mexico, we found the three site types were similar in vegetation composition and structure and differed only in the presence or absence of black-tailed prairie dogs; however, there were differences in the vegetation between haw use areas in Mexico. Mexico sites had intensive grazing and less vegetation cover and overall shorter vegetation. Vegetation composition and structure did not seem to influence winter habitat selection in Ferruginous Hawks; instead, it was directly correlated with occupied black-tailed prairie dog colonies.