Spring diet of the endemic ring-tailed cat (Bassariscus astutus insulicola) population on an island in the Gulf of California, Mexico

The spring diet of an endemic ring-tailed cat (Bassariscus astutus insulicola) population of Isla San José, Gulf of California, Mexico, is presented based on the analysis of 104 faeces. The ring-tailed cat is an opportunistic species, concentrating on the predation of mainly small prey, and has a richness of prey of 36 animal taxa and 12 plant species. The most important prey were found to be mainly Orthoptera, Tenebrionida, and Scorpionoidea, Chaetodipus spinatus and Neotoma lepida. Chilomeniscus cinctus, Cnemidophorus, and Sceloporus were the most important reptile species. Among the plant species, of particular importance were the fruits of Lycium,Solanum , Phaulothamnus, and ironwood leaves. The spring diet of the ring-tailed cats of Isla San José differs from the diet of all other mainland populations, in that the proportion of reptiles (50% of occurrence) and invertebrates (91%) were found to be of the highest ever reported, even when compared with other seasons.