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 insulico la) population of Isla San Jose, Gulf of California, Mexico, is presented b ased 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 ri chness of prey of 36 animal taxa and 12 plant species. The most important p rey were found to be mainly Orthoptera, Tenebrionida, and Scorpionoidea, Ch aetodipus spinatus and Neotoma lepida. Chilomeniscus cinctus, Cnemidophorus , and Sceloporus were the most important reptile species. Among the plant s pecies, of particular importance were the fruits of Lycium, Solanum, Phaulo thamnus, and ironwood leaves. The spring diet of the ring-tailed cats of Is la San Jose differs from the diet of all other mainland populations, in tha t the proportion of reptiles (50% of occurrence) and invertebrates (91%) we re found to be of the highest ever reported, even when compared with other seasons. (C) 2000 Academic Press.