Nesting dispersion of a Black Kite population in relation to location of rabbit warrens

Abstract

Previous studies have shown that the rabbit (Oryctolagus cuniculus) is the main prey of the Black Kite (Milvus migrans) in Matasgordas (Doñana National Park, southwestern Spain), and that the reproductive success of pairs is enhanced with increasing rabbit consumption. In our study area, rabbits live mainly in large warrens patchily distributed across the breeding area of Black Kites. Rabbit consumption was higher for Black Kite pairs having warren entrances close to their nests. During the 3 years of the study, this population of Black Kites suffered a considerable increase. New pairs in the area selected nesting trees inside areas with a high density of rabbits. The pattern of Black Kite aggregation in our study area, where they breed in a "colony" with a population density among the highest recorded, can be explained, at least partially, by rabbit aggregation. Defense of feeding resources could help to explain the territorial behavior of Black Kites. Coloniality and feeding territoriality are not mutually exclusive.