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 km 2 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.

Ecological Flexibility of the Top Predator in an Island Ecosystem — The Iriomote Cat Changes Feeding Patterns in Relation to Prey Availability

“…During nursing periods, females with young concentrated their movements near the den [47]. In the present study, the proportions of rice fields and swamps in home ranges of three females were higher than those of other vegetation types during the period.…”

“…This is likely the result of different climates, vegetation structures, or the principal prey species present in completely different environments. For leopard cats Prionailurus bengalensis, home range sizes differ among broad regions in Thailand [49][50][51], in Borneo [52], on Tsushima Island [53] and on Iriomote [5,47,54]. On Iriomote, the vegetative and topographic conditions significantly differed among the study sites, which were only several kilometres away from one another.…”

Ecological Flexibility of the Top Predator in an Island Ecosystem - Food Habit of the Iriomote Cat

“…Therefore, I suggest that the Iriomote cat can endure on its small island despite a poor mammalian fauna by means of shifting principal prey items to seasonal migrators, particularly during winter. It is during this winter period, that the mating season of the cat takes place (Okamura et al, 2000); home range size and activity of male cats increase Schmidt et al, 2003Schmidt et al, , 2009). Thus, the food requirement of the cat should increase in that time.…”

“…Indeed, home ranges of leopard cats on the continent largely shift depending on wet and dry seasons and its sizes are much larger (Rabinowitz, 1990;Grassman, 2000Grassman, , 2005 than those of Iriomote cats Schmidt et al, 2003). In restricted habitats such as small islands, however, predators have to remain in the same habitats during periods of prey resource scarcity.…”

“…Therefore, the cats may shift their feeding tactics when switching their principal prey items. The movement pattern of the Iriomote cat varies in relation to seasons and local differences of habitats Sakaguchi, 1991;Schmidt et al, 2003Schmidt et al, , 2009. It may also vary in relation to shifting feeding patterns of the cat depending on seasonal difference of principal prey items.…”