This paper examines the relationship between alveolus eruption, eruption stage the of Japanese archaeological pig teeth, and the actual age at death based on the analysis of modern captive wild boars which are the progeny of trapped and confined wild boars kept for less than several generations. The timing of molar eruption for both maxillae and mandibles for both captive and wild boar populations was also investigated. The results indicate that the attrition pattern in molars varied between individuals with exactly the same age at death and even between those that were kept under the same conditions and diet. The variation in the eruption pattern of maxillae and mandibles was also observed, with molars erupting relatively earlier in maxillae compared to the mandibles in both captive and wild populations. It became clear that separating “M2 erupted” individuals and “M3 erupting” individuals into different age group as done by many researchers should be avoided because of overlap. A method based on the eruption status of the last tooth of the tooth row was established and then applied to archaeological pig material excavated from the Haneo and Torihama shell-middens, Japan, both dated to the Early Jomon Period (ca.7000 to 5500BP). Two Jomon assemblages reveal a different pattern, with a relatively higher frequency of younger individuals represented at Torihama and a relatively higher frequency of older individuals at Haneo.

Cohort analysis (also known as virtual population analysis) is a method of population reconstruction from age-specific harvest data. Because cohort analysis requires data over a whole life span to reconstruct a population for a single year, this method is impracticable for longer-lived animals. Three models are routinely combined by fisheries scientists to make cohort analysis more cost effective and to provide real-time estimates of population size; these models may be applied to large terrestrial mammal harvest data. Each model has unique assumptions about hunting mortality rates or age distributions, and the reliability of estimates depends on meeting these assumptions. In this study, we first tested previously used assumptions for these models through an analysis of long-term moose (Alces alces) harvest data, followed by an examination of the robustness of estimates for each moose age class. We developed practical ways to achieve more realistic assumptions for two of three models and showed that meeting these assumptions was more important in estimations of large terrestrial mammal population parameters than for fish population parameters. Therefore, we recommend compliance with assumptions of the three models for more reliable population estimates of large terrestrial mammals.

We developed a predictive model and map characterizing human-Asiatic black bear contact in Yamanashi Prefecture, central Japan. Our goal was to understand the relationships between human-bear contact and landscape-level physiographic and human variables and to identify potential areas of high risk for contact. Models for years of normal contact and years of recurrent contact were not significantly different. Consequently, the areas of high contact risk were fixed. An integrated model using both normal- and recurrent-year data indicated that the factors affecting contact were, in descending order: distance from forest edge, ratio of conifers to total forested area, bear distribution, and distance from settlement. The classification accuracy of the predictive model was 82.0% (sensitivity 82.0%, specificity 82.0%). This highly accurate predictive map and model may serve as effective tools for reducing human-bear encounters.

The conversion and loss of primary rainforest in Southeast Asia is presumed to affect many animal assemblages in terms of their diversity and species composition. We studied the responses of non-volant small mammals to forest loss and degradation caused by logging and the establishment of large-scale oil palm plantations located in the north-eastern part of Borneo in Southeast Asia. We found that habitat types (forest versus plantation) were important determinant of species occurrences and assemblage compositions. However, within forest habitats irrespective of whether logged or unlogged, similarities in assemblage compositions of sites close to each other underline the importance of geographic distance in shaping small mammal assemblages. In terms of conservation management, it is imperative to incorporate the size and overall surrounding environment of a forest into forest management concepts, and although not equivalent to areas of primary forest, old regenerating secondary forest needs to be considered as an important component for the preservation of small mammal species diversity. In contrast, oil palm plantations are clearly of little or no importance for the conservation of the non-volant small mammal fauna and this habitat may also act as an effective barrier to the dispersal of the small mammals.

In order to conserve mammalian top predators in human-dominated landscapes, large scale habitat requirements and food habits of the Japanese weasel (Mustela itatsi) were studied using 237 faecal samples, from a 901 km² area in the vicinity of Mito City, Ibaraki Prefecture, Japan between 1999 and 2001. Findings show a significant difference in the faeces distribution among the nine biotope types surveyed, with a marked preference for rice fields and conifer plantations, coupled with an avoidance of farming and urban areas. In terms of weasel diet, mammals occured most frequently in relative volume and single occupancy in faeces and most often observed in conifer plantations along river banks. Second, Orthoptera insects, crustaceans, fruits, Coleoptera insects and fish were also found both in high frequency and relative volume, most often in rice fields and riparian habitats along river banks. Third, a high frequency of occurrence among combinations of (1) mammals with Coleoptera insects and (2) crustaceans with Orthoptera insects suggests the necessity of interaction among habitats. Artificial items were rare. These patterns provide evidence that weasels require diverse landscapes and further suggest weasels do not use urban areas because of their predatory preference for fresh animal food. This has implications for weasel conservation strategies.

To identify common and general environmental factors that affect the distribution of conflict-causing four animals, predictive distribution models and a predictive distribution map for central Japan were developed. A conditional autoregressive model was used to develop these models. All species avoided unforested areas and preferred farmland near the forest edge. Areas in which hard mast-bearing species dominate were preferred by wild boar, sika deer and Asiatic black bears; grassland was also preferred by wild boar and sika deer and Asiatic black bear. Densely populated areas were avoided by both ungulate species. In terms of climate factors, wild boar and Japanese macaques avoided areas with low winter temperatures, and wild boar, sika deer, and Asiatic black bears avoided deep snow. Preventing conflict-causing animals from using farmland is the most reliable method of restricting their distributions.