THE DIET OF THE DIADEM LEAF-NOSED BAT HIPPOSIDEROS-DIADEMA - CONFIRMATION OF A MORPHOLOGICALLY-BASED PREDICTION OF CARNIVORY

The diet of Hipposideros diadema was investigated over three seasons a t two sites on Cape York peninsula, Australia using faecal analysis (a t both sites) and prey remains identification (at one site). The possi bility that this species feeds on terrestrial vertebrates, a behaviour here referred to as carnivory, was suggested by the similarity of thr ee of its morphological features with those of eight of the 10 species of bats known to exhibit carnivory. The study confirmed that H. diade ma is at least occasionally carnivorous. Bird feathers were found in f aeces at both sites; however, their occurrence was limited to a collec tion of faecal pellets from the early dry season at Iron Range and a s ingle pellet from the wet season at Chillagoe. The birds taken could n ot be identified to family or species. Coleoptera, Lepidoptera and var ious orthopteroid orders were the main insect taxa in faecal pellets. The frequency of these taxa in the diet varied significantly among the three seasons at both sites. Analysis of prey remains indicated that large, hard-bodied insects, mainly cerambycid and scarabaeid beetles a nd acridid grasshoppers, particularly the locust Gastrimargus musicus, were taken frequently. The mean length of intact beetle elytra collec ted below roosts was 18.0 mm. No vertebrate material was found in prey remains. Hipposideros diadema is similar to several other bats which exhibit carnivory in preying infrequently on vertebrates. The term 'pa rtial carnivore' or 'occasional carnivore' is suggested for these spec ies.