Breeding biology, nesting habitat, and diet of the Rock Eagle-Owl (Bubo bengalensis)

The Rock Eagle-Owl (Bubo bengalensis) was recently recognized as a species, with a distribution restricted to the Indian subcontinent. We studied breeding biology, habitat use, diet, and nesting density of 44 pairs of Rock Eagle-Owls in western Maharashtra state (India) for two successive breeding seasons (2004-05 and 2005-06). We present here for the first time (a) egg shell thickness (0.305 ± 0.001 mm; range: 0.303-0.306 mm); (b) egg-laying interval (1.7 ± 0.5 d; range: 0.54 d); (c) incubation period (3334 d); (d) hatching pattern (asynchronous); (e) breeding success (1.5 ± 0.9 fledglings per occupied nest; range: 0-4 fledglings); and (f) post-fledging dependency period (6 mo, from April to September). Most productive nesting territories have several alternative nest sites and open landscapes such as agricultural lands and scrublands, which offer high-value foods including rodents, birds, and chiropterans. Early onset of breeding was positively correlated with the presence of high-value foods in the diet.