The Diet of the Black Vulture (Aegypius monachus) in Extremadura in response to environmental the changes in Extremadura (1970-2000)

Abstract

Aims: The main aim of the present study was to determine how the black vulture Aegypius monachus has adapted in the past to the decline and eventual scarcity of the populations of its principal prey, the rabbit Oryctolagus cuniculus, and how it is adapting now to the new availability of food in its environment. Location: The study was carried out in the Sierra de San Pedro (Extremadura, SW Spain). Methods:To achieve the aim, the diet of this carrion feeder in the 1970s (Hiraldo, 1976) was compared with that recorded in the period 1998 - 2000. The method used was based on analyzing fur-ball pellets collected in visits to nests over an annual cycle (125 pellets, 167 preys). Results: In the 1970s in the Sierra de San Pedro, this carrion feeder based its diet on carcasses of medium and small sized animals, with the rabbit constituting the key food item. In response to the growing scarcity of this prey, the black vulture has changed its feeding habits and now the percentage of rabbits in its diet is very low, having been replaced by sheep Ovies aries supplemented with other prey (swine and deer). Conclusions: The major growth of these resources and the protection of the species have led to the recovery of its populations. This capacity of the black vulture to adapt to change in the availability of prey may be a key element in the future conservation of the species, since new changes have recently been taking place in the availability of these resources (greater control of livestock carcasses and new European Community policies).