The bat-eared fox: A dietary specialist?

Abstract

We studied the degree of dietary specialisation of bat-eared foxes (Otocyon megalotis) by analysing 177 scats collected on a game ranch in central South Africa. Bat-eared foxes generally are considered to be insectivorous with a distinct specialisation on termites, however, our results indicated a much broader and opportunistic diet. Termites were detected in more than 90% of the scats throughout the year, but they only contributed 12–40% to the ingested biomass across seasons. Instead, fruits, primarily bluebush (Diospyros lycioides), were the most important food category in summer (63% biomass) as well as in autumn (74% biomass). Also, high niche breadth values (B=5.7–6.9 for frequency of occurrence, B=1.8–4.1 for biomass data) indicated a rather generalistic feeding behaviour. We also documented numerous cases of opportunistic scavenging on carcasses by bat-eared foxes. The difference with earlier dietary studies of bat-eared foxes might be attributable to geographical and ecological variations among sites and also partly to methodological differences. Concerning the latter, no previous studies considered biomass calculations but instead most assessed the frequency of occurrence of prey items, which likely overestimated the importance of small prey such as termites.