NESTING HABITAT USE BY BURROWING OWLS IN COLORADO

Habitats used by nesting Burrowing Owls (Speotyto cunicularia), and the fidelity shown to traditionally used nesting areas were studied in 1990 and 1991. Nesting Burrowing Owls (N = 47 pairs) occupied burrows with a shorter distance to the nearest road, and shorter grass and forb height (P < 0.005) than generally available, while using black-tailed prairie dog (Cynomys ludovicianus) towns with greater burrow density, nearest perch distance, and percentage of bare ground (P < 0.05) than available. Of adults banded in 1990, 39% returned in 1991, while only 5% of chicks banded in 1990 returned. Of returning adults, 66% reused the same prairie dog town used the prior year. From 1990 to 1991, 90% of prairie dog towns were reused (N = 18), and 20% of nesting burrows (N = 4) were reused. Burrowing Owls exhibited a strong fidelity to previously used nesting towns, and were moderately site-specific in nesting habitat requirements.