Behavioural and morphological adaptations for a low-quality resource in semi-arid environments: dung beetles (Coleoptera,Scarabaeoidea) associated with the European rabbit (Oryctolagus cuniculus L.)

In semi-arid Iberian ecosystems, the dung beetle community associated with rabbit dung heaps shows high complexity in spite of adverse factors, such as the low water and nutritional content of rabbit pellets and the arid climate of environments. A total of 24 species showing optional telecoprid, paracoprid and endocoprid (including kleptocoprid) patterns were studied. Acquisition of many morphological adaptations from aridity (flightlessness), exploitation of dry dung (mouthpart modifications) and behavioural specializations are described. These adaptations may explain the exploitation of dry dung and the high rate of endemism observed in the dung beetle community studied. All morphological and behavioural specializations described can be considered as derived characters for the exploitation of fibrous and dry dung, showing a secondary evolutionary line that suggests the return of these beetles to saprophagy.