Home range area and habitat use of the wild Japanese macaque (Macaca fuscata) were investigated between elevations of 600 m and 3000 m in the Northern Japan Alps, in areas where there is great variation in vegetation type. A total of 22 troops were located either visually or by radiotracking from December 1996 to February 2000. The average troop size was 48.4 individuals, the average ranging area (65% probability distribution calculated using the adaptive kernel method) was 3.7 km2 and the average elevation of each troop varied from 740 m to 1458 m. Two troop types were distinguished according to their habitat use: (i) ‘rural’ type groups frequently utilized cultivated land (n = 12); and (ii) ‘natural’ type groups never utilized cultivated land (n = 10). Natural groups inhabited higher elevation areas and showed a greater dependency on deciduous broad‐leaved forests during all seasons. In contrast, rural groups utilized the larch plantation more in spring, and the red pine forest in summer. Rural groups were observed on cultivated lands more often from summer to winter than in spring. The size of the rural groups was twice as large as that of the natural groups. Troop size and home range area showed significant correlation within each group type. The per capita home range area of rural groups was smaller than that of natural groups. These results suggest that per capita home range area is negatively correlated with habitat quality.

Abstract. Habitat use by Asiatic black bears (Ursus thibetanus) was examined in the Northern Japan Alps where distinct changes in the vegetation occur with elevation. Seven bears (three males and four females) were radio-tracked for five years. Home range size varied from 32 to 123 km 2 , and bears used habitats at elevations between 600 m and 3,000 m. Bears used higher elevations (2,100 to 2,300 m) in summer (from July 1 to September 10), and lower elevations (1,000 to 1,500 m) in autumn (three months after September 10). Bears foraged in subalpine birch forests, avalanche chutes, or the alpine zone in summer, but moved to the deciduous broad-leaved forests of the montane zone in autumn. Bears spent little time in mid-elevation (2,000 m) coniferous forests. Seasonal movements among habitats at different elevations are likely necessary for survival in marginal alpine habitats.

The time it takes for ingested seeds to pass through the gut of animals is an important aspect of endozoochorous seed dispersal because it influences seed dispersal distance. Variations in the physical characteristics of seeds, such as their weight, volume, and specific gravity, can affect their movement through the gastrointestinal system of a given animal. We conducted feeding experiments with captive Japanese martens, Martes melampus (n=4), at Toyama Municipal Family Park Zoo, central Japan to examine the effects of the physical characteristics of seeds on their passage times. The mean (±SD) transit time, mean retention time, and time of last appearance of four different types of commercial seeds were 2.6±0.3 h (range 0.6-5.4), 9.7±1.1 h (3.8-17.3), and 23.8±3.1 h (12.2-51.8), respectively. All of these values are greater than those found during previous experiments conducted with mustelids. Similar to previous studies, however, none of these passage time variables was correlated with the physical characteristics of seeds. Our results thus indicate that martens disperse seeds of different plant species, whose size, volume, and specific gravity all fall within the range of those used in the present study, from parent plants at similar distances.

No abstract

To examine the effects of food intake on the gastrointestinal passage time of seeds in the Japanese marten (Martes melampus), we conducted four feeding experiments using captive animals (n = 4). We estimated passage time variables (transit time and mean retention time) of plant seeds (two types) using two different numbers of chicks (single and three) representing two seasons when the animal prey is abundant/scarce. There was no significant relationship between food intake and passage time, and seed type did not affect the passage time variables. Our results were different to those for herbaceous/omnivorous mammals, in which a shorter passage time was observed when food intake increased. The stability in the passage time of the martens could be attributed to the higher level of digestibility of the animal prey. Our data also suggests that martens possess an elastic gut that can expand in volume, which leads to a consistent passage time despite the increase in food intake and enables them to efficiently assimilate nutrients from the consumed food. The results of the present study suggest that the dispersal distance of seeds and defecation site density of martens is influenced by their ranging/activity pattern and not by their digestive physiology.