NESTING HABITAT USE BY BURROWING OWLS IN COLORADO

Habitats used by nesting Burrowing Owls (Speotyto cunicularia), and th e fidelity shown to traditionally used nesting areas were studied in 1 990 and 1991. Nesting Burrowing Owls (N = 47 pairs) occupied burrows w ith 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 pr eviously used nesting towns, and were moderately site-specific in nest ing habitat requirements.