The reproductive tactics and activity patterns of solitary carnivores: the Iriomote cat

Abstract

Felids are generally considered to be crepuscular and nocturnal in their activity, but few studies have attempted to analyze the variability of their activity patterns. We studied the daily activity of the Iriomote cat Prionailurus iriomotensis by radio-tracking on Iriomote Island, Japan. The general activity patterns of Iriomote cats showed slightly prevailing activity during dark periods of the day with particular peaks at dawn and dusk or during the early hours of the night. However, these patterns were clearly dependent on the sex and reproductive status of the cat. Peaks of cats' activity coincided with those of their main prey. On average, the cats were active for thirteen hours per day. During the mating season, the rhythm of activity in males followed that of breeding females, but not that of non-breeding ones. Males exhibited 11% higher total daily activity and longer active bouts during the mating period than in the remainder of the year. Breeding females had additional mid-day activity peak during the nursing period, but their total time of activity per day was 16% lower than in the period of kittens' independence. Their active bouts were shorter and more frequent during nursing than at other times. These results suggest that lactating females perform frequent movements to and from the den site to care for kittens. During the non-nursing period, females increased their activity, possibly in response to lowered prey abundance and the need of intensive foraging to recover after lactation. Seasonal and sexual variation of activity patterns in the Iriomote cats confirmed the existence of different reproductive strategies of males and females of these solitary carnivores.

Effects of Human Activities on Home Range Size and Habitat use of the Tsushima leopard Cat Prionailurus bengalensis euptilurus in a Suburban Area on the Tsushima Islands, Japan

“…Our results were similar those from previous studies of leopard cats in other region (Thailand; Rabinowitz 1990, Grassman et al 2005, Iriomote island in Japan; Schmidt et al 2009), which reported that cat activity patterns were related with those of their prey. The main prey of the Tsushima leopard cat is small mammals (Inoue 1972, Tatara andDoi 1994), and two species of, murids (Apodemus speciosus and A. argenteus), their most important food items (Tatara and Doi 1994, Moteki unpublished), tend to be nocturnal (Nakata et al 2009).…”

“…The main prey of the Tsushima leopard cat is small mammals (Inoue 1972, Tatara andDoi 1994), and two species of, murids (Apodemus speciosus and A. argenteus), their most important food items (Tatara and Doi 1994, Moteki unpublished), tend to be nocturnal (Nakata et al 2009). Schmidt et al (2009) reported that the activity of the Iriomote leopard cat seemed to be related with the period of peak activity of their main prey species: the evening peak of cat activity reflected peaks in vocal activity of several amphibians and the morning peak reflected a period of high activity of bird species. The activity patterns of the radio-collared cat in our study seemed to mirror those of the Tsushima leopard cat's main prey, small mammals.…”

“…The daily movement distances (DMD) do not reflect the actual distance moved, because DMD may be somewhat underestimated in studies of radio-tracked animals (Jędrzejewski et al 2002, Schmidt et al 2009). However, it is possible to make general comparisons with other individuals of the same species.…”

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.…”

“…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.…”