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

We studied winter habitat use of Ferruginous Hawks (Buteo regalis) from Nov ember 1999-February 2000 in southern New Mexico and northern Mexico by comp aring vegetation in New Mexico among three potential hawk habitat types; oc cupied black-tailed prairie dog (Cynomys ludovicianus) colonies (N = 13), a reas without prairie dogs that had historical records of occurrence (N = 7) , and general grassland areas (N = 8). In Mexico, we recorded habitat use o f hawks observed during driving surveys. Overall, 20 of 22 Ferruginous Hawk s observed throughout the study were associated with occupied black-tailed prairie dog colonies. In New Mexico, we found the three site types were sim ilar in vegetation composition and structure and differed only in the prese nce or absence of black-tailed prairie dogs; however, there were difference s in the vegetation between haw use areas in Mexico. Mexico sites had inten sive grazing and less vegetation cover and overall shorter vegetation. Vege tation composition and structure did not seem to influence winter habitat s election in Ferruginous Hawks; instead, it was directly correlated with occ upied black-tailed prairie dog colonies.