The effects of a few decades of habitat fragmentation on the population genetic diversity of the large Japanese field mouse, Apodemus speciosus, in the forest region around Fukuyama University was assessed with approximate 300 bp nucleotide sequences of the mitochondrial D-loop region. Two independently isolated internal populations within the campus showed a smaller number of haplotypes and lower haplotype and nucleotide diversity indices compared to those inhabiting a wide external forest area. Based on the Hst index, significant genetic differentiation was observed between geographically closely residing external and internal populations but not between distantly residing external populations, suggesting the presence of strong physical barriers between the external and internal populations. Fine-scale changes in the landscape configuration recorded in aerial photographs of Fukuyama University revealed plausible physical barriers and a correlation between isolation time and genetic diversity. The results suggest that the population genetic properties of forest dwelling mammals are sensitive to a few decades of short-term forest fragmentation created by artificial construction. Exploitation by humans should be conducted in harmony with wildlife ecology, such as by maintaining corridors, to achieve a wide habitat area for gene flow.

The genetic structures of animal populations are influenced by the difference in the dispersal patterns of the sexes. To reveal effects caused by different dispersal systems between sexes on genetic structure, we examined the differences in the distribution of mitochondrial DNA in Asian black bears and compared the relationship between genetic correlation coefficients and pairwise distances of the bears between sexes using microsatellite DNA. From sequences of 758 black bears from continuous populations, we examined sequence data for 326 samples carrying ten haplotypes that were distributed locally. The estimated pairwise rectilinear distances indicated that males tended to distribute around the inner edge of the observed area of the locally distributed haplotypes. Distribution range analysis showed that both the maximum and average ranges of males in eight locally distributed haplotypes were larger than those of females. We also performed spatial autocorrelation analysis using genotype data for microsatellite DNA from 50 bears for which samples were collected from hair-traps. The genetic correlation coefficients were significantly higher than expected within the 0–10-km-distance class for females and the 0–20-km-distance class for males. These results revealed that males expanded the haplotype distribution and mediated gene flow.

To investigate the factors that influence resting site preference of the Japanese dormouse Glirulus japonicus, we determined the effect of tree resources in a microhabitat on the use of nest boxes as daytime resting sites. The study area, which was in Mt. Nagakura National Forest in central Japan, was divided into 200 plots. In each plot, a nest box specially designed to harbor dormice was attached to the trunk or branch of a tree. All living trees in the microhabitat around nest boxes were recorded and categorized into 3 resource types: food, nesting materials, and other resources. We then incorporated a generalized linear model to determine how resource types affected the frequency of nest box use by dormice. A positive correlation was observed between the frequency of nest box use and abundance of trees of lower strata that were used as food resources. On the other hand, the abundance of trees categorized as other resources was negatively correlated with the frequency of nest box use. These findings suggest that dormouse resting site preference is influenced mainly by the abundance of food resources in the microhabitat.

Although population size is one factor affecting the intensity of wildlife damage, the relationship between damage and population size is unclear. We propose a new hypothesis that: the open land preference affects the intensity of crop damage. We defined the open land preference based on the behavioral traits of each individual showing dependence on farmland. If the open land preference of a population increases, crop damage increases because individuals with a high open land preference frequently use farmland. Based on ethological perspectives, this hypothesis assumes population ecology and ethology best explain damage by wildlife. We used long-term wildlife camera trap data collected from orchards. These data confirmed increased rates of damage from sika deer (Cervus nippon) were higher than the population growth rate. Initially, wildlife mainly used farmland at night during the summer, but gradually the deer changed their farmland-use patterns to other seasons and during the day. These results indicated: i) the increasing rate of damage from deer could not be explained by population size alone and ii) increased damage was accompanied by a behavioral change in deer. This behavioral change corresponds to the change in the open land preference and the data supported our hypothesis.

The diet and feeding habits of Eurasian otters (Lutra lutra) were studied by spraint analysis over a one year period on the four sections of the Jajrood River, eastern Tehran. Two methods were used to estimate the proportions of different prey consumed: frequency of occurrence and score-bulk estimate. The number of prey categories in a spraint varied between one and four. Fish, crabs, birds and insects were found in the spraints. Fish is the main prey. Otters mainly eat fish, preferring three species: the chub (Leuciscus cephalus), riffle minnow (Alburnoides bipunctatus) and various barbel (Capoeta spp.) species. The otters' diet differed significantly across four sites positive for otter sign. Seasonal variation was also found: birds were taken more in the cold season and insects in the warm season. The proportion of crab in the diet was almost constant throughout the year. Leuciscus cephalus was the most taken fish species in the cold season and Capoeta spp. in the warm season. Only L. Cephalus appeared to be preferred. There was no significant correlation between the estimated proportion of fish in the diet and relative prey fish population at any of the four studies sites.