Importance of Rabbits in the Diet and Reproductive Success of Black Kites in Southwestern Spain

Abstract

The rabbit Oryctolagus cuniculus is the most common prey of many predators in Mediterranean ecosystems, but how its abundance affects the productivity of its predators has been poorly studied. The Black Kite Milvus migrans is a generalist predator, but in our study area eats mainly rabbits. There was considerable year to year variation in the proportions of the nine prey types examined in the diet. The abundance of young and sick rabbits seemed to determine the consumption rate of rabbits by Black Kites. Interannual variation in reproductive performance (chick starvation mortality, fledging weight and length of the nestling period) was related to the proportion of rabbits in the diet, a year of high performance coinciding with a high proportion of rabbits in the diet. Some factors explaining the importance of rabbits for the reproductive success of this raptor are discussed.