Movements and use of home range in the Iriomote cat (Prionailurus bengalensis iriomotensis)

Abstract

Movement pattern of the Iriomote cat Prionailurus bengalensis iriomotensis was studied on Iriomote Island, Japan by radio-tracking. The influence of sex and reproductive status of cats on their daily movement distance (DMD), straight-line distance (SLD), daily movement range (DMR) and other relative indices of movements was estimated. DMD was longest in males (3.2 km) and shortest in females without kittens (1.9 km). Also, males moved faster than either females with or without kittens (0.34, 0.25 and 0.25 km/h, respectively). During the mating season, males moved faster and their DMRs were larger than during the rest of the year. The SLD/DMD ratio in males was similarly high in both seasons (0.29 and 0.33), which indicates that their daily routes were expanded over large areas year-round, possibly to maintain a continuous control over their home range. In contrast, SLD/DMD varied seasonally in breeding females. It was low (0.09) during the lactating period, when females returned repeatedly to the den with kittens and it became high (0.32) out of the breeding season. Breeding females moved equally long DMDs in both seasons, whereas non-breeding ones moved shorter distances during the breeding period. These differences may be related to seasonal changes of food abundance. Cats moved intensively, as indicated by long (812–1139 m) routes per km² of their home range, and occasionally visited distant parts of their ranges in a short time (4–5 days). On the other hand, they showed a relatively slow increase of the patrolled area, from 10% to 36% of their home ranges, in the first and fifth day, respectively. Movement pattern of Iriomote cats showed no clear relation to active defence of home ranges.