To further understand the population structures of the Japanese badgers (Meles anakuma) on the Japanese islands, we analyzed their bi-parentally inherited microsatellites. Based on genotypes of nine microsatellite loci, the badgers were divided into five discrete clusters: three clusters from the Honshu Island, one from Kyushu and one from Shikoku. We propose that this genetic differentiation among badgers from the Honshu, Shikoku and Kyushu Islands is as a consequence of geographical isolation caused by the Seto Inland Sea. Furthermore, the cluster containing individuals from Shikoku was more differentiated from the other clusters, plausibly attributable to the earlier geological separation of the Shikoku Island from the Honshu and Kyushu Islands. The three clusters in Honshu, however, did not correspond precisely with geographical locations. As indicated in previous studies, based on mitochondrial DNA analysis, the genetic relationships within the Japanese badgers might reflect recent population expansion, occurring over a relatively short evolutionary time-scale. The findings preliminarily indicate that the Japanese badgers do not possess the high levels of philopatry seen in the European badger (Meles meles), a closely related species, although further analyses using balanced sample sizes from a wider range is required.

We determined the food habit of the Asian parti-coloured bat Vespertilio sinensis from May to August by analysing their faecal samples. Eight orders of insects were identified in the faeces. Lepidoptera, Diptera and Coleoptera had high frequencies of occurrence, but the proportion of each order varied with the sampling period. A comparison between diet composition and relative insect abundance showed that proportions of Coleoptera in the diet were larger than those in insect abundance. This pattern also was true for Lepidoptera in some sampling periods. In contrast, proportions of Diptera in the diet were lower than those in insect abundance, although Diptera was a major prey item. These results suggest that the diet composition of V. sinensis may be biased towards larger-sized taxa. Furthermore, the lack of any significant differences between diet composition and insect abundance for the other five orders suggested that the diet composition of V. sinensis is also influenced by the seasonal prevalence of each insect taxon.

The effect of hunting on sika deer (Cervus nippon) was investigated through detailed investigations of their pasture utilization during autumn and winter by using a Global Positioning System (GPS) tracking collar. The study was conducted around a pasture in Nagano Prefecture, Japan. Before the hunting season, while the stockmen stayed in the pasture during the daytime, the collared deer preferred to utilize the pasture during the nighttime. However, at the beginning of the hunting season, the collared deer moved to a precipitous plantation of Japanese larch, located approximately 4 km north-east of the pasture. During the hunting season, the collared deer stayed there and avoided the pasture during the entire day, while after the hunting season, the collared deer preferred to utilize the sunny and clement pasture during the day as there was no human disturbance. These results showed that the behavior and habitat utilization of sika deer were affected by hunting. Thus, it was concluded that sika deer sensed the hunting activities and the presence of humans in the pasture, and altered their behavior to utilize the pasture when it was comparatively safer and more comfortable.

The Okinawa spiny rat, Tokudaia muenninki, is a critically endangered species endemic to the northern part of Okinawa Island and may be extinct in the wild as there have been no recent sightings of the animal in its natural habitat. We initiated the present search to determine whether the spiny rat still exists in the northern part of Okinawa Island. Sensor cameras and traps were distributed across areas in which past studies had identified the location of occurrence of spiny rats. From a total of 1,276 camera-nights and 2,096 trap-nights from 2007 to 2009, we captured 24 spiny rats; however, we were only successful in identifying spiny rats in the northernmost of the areas sampled, with no indications of the spiny rat in the more southerly areas. The area in which the spiny rats were still present was estimated to be only 1–3 km² and is comprised of forest dominated by Castanopsis sieboldii, Lithocarpus edulis, Distylium racemosum and Schima wallichii. The trees range in age from about 30 to more than 100 years old, and have an average height of 12 m (range 7 m–16 m). Our rediscovery of the spiny rat in 2008 comes after an interval of 30 years since the previous trapping study in 1978 and seven years since indirect survey evidence from analysis of feral cat feces 2001. Measures for conservation of the location of the spiny rats are urgently required.

Dietary composition, fecal crude protein, plant fragment sizes, and their fragmentation processes through the digestive tract were compared for sika deer and Japanese serow in northern Japan. Dwarf bamboo and graminoids were important food plants for sika deer, whereas dicotyledonous leaves, particularly those of evergreen shrubs, were important for Japanese serow. Fecal crude protein was always higher and fecal plant fragments were smaller in Japanese serow than in sika deer. Japanese serow digested plants better and fragmented plant material through the digestive tract more markedly than did sika deer. Two interpretations are possible: smaller fragments in serow feces resulted from 1) differences in food availability in the habitats, or 2) differences in digestive physiology of the two ungulates. Although this study suggests the latter interpretation, more studies of sympatric populations are needed.

To elucidate the relationships between the Japanese serow (Capricornis crispus) and their habitat, we conducted a survey of the population density, home range size, reproductive performance, and forage quality and availability mainly in winter. We compared these traits among three populations living in different habitats, Shimokita, Asahi and Kamikochi, based on field observation and published data. Reproductive rate, based on the number of kids that mothers reared to one year old, was highest for Shimokita (37.0%), followed in order by Asahi (29.6%) and Kamikochi (12.0%). Correlations were found among winter forage availability, home range size, reproductive rate and population density, when evergreen coniferous species were considered to have low food value for serows. We concluded that all of these factors could be useful indicators of habitat quality for the Japanese serow. The present results suggest that a small range size and high reproductive success, supported by appropriate food conditions, result in a high population density of the Japanese serow in mild habitats such as Shimokita, whereas the opposite is true in severe habitats such as Kamikochi.