Importance of frogs in the diet of the Iriomote cat based on stomach content analysis

Abstract

This study aimed at providing new insight into the dietary habits of the endangered Iriomote cat (Prionailurus bengalensis iriomotensis) by examining the stomach contents. Using this method allowed for more reliable representation of the diet than the analysis of scat content as used in previous studies of this subspecies. We applied five indices: frequency of occurrence, relative frequency of occurrence, relative weight, relative number of individuals, and occupancy rate of weight in a stomach to design a multifaceted evaluation of diet. A variety of organisms (21 species and six categories in eight classes) were found in the stomachs. Amphibia and Aves occurred in the highest frequency (58.06 % each). The Sakishima rice frog (Fejervarya sakishimensis) was found to be the most frequently consumed prey. Of all classes, only the frequency of occurrence of Amphibia differed significantly between stomach and scat contents (G-test, p < 0.01), which suggests an underestimation of amphibians in the scat analysis. The stomach content analysis allowed for obtaining data on foraging by juvenile Iriomote cats and revealed that young individuals start consuming a variety of animals, including frogs and snakes at the age of 4 to 5 months. This study emphasized the importance of frogs as prey of the Iriomote cat, and as such, it is the first investigation of this cat species based on stomach contents.