Mammal Study

The Japanese field vole Alexandromys (Microtus) montebelli is prevalent in apple orchards and is the dominant cause of damage to fruit trees during winter. A recent study revealed that the Japanese field vole bred and increased its population during winter in regions with deep snow. Understanding what food resources support the voles during winter can assist in formulating a better understanding of the factors of the annual variations in orchard damage. In this study, we sampled faeces of the voles from November 2018 to May 2021 and performed the DNA metabarcoding analysis for plant dietary profiling with a molecular marker on the internal transcribed spacer region in the nuclear genome. We obtained results from 60 samples, and the food sources detected most frequently were the broadleaf docks Rumex obtusifolius, followed by the cultivated apples Malus spp. The detection frequency of Fabaceae sp. declined after March, and the one of apple rootstocks increased instead. During March and April, the various parts of fruit trees and Rumex spp. were the main diets for most of the voles. The biomass supplied by herbaceous plants, especially Rumex spp. could affect the extent of vole damage to fruit trees in winter.

Currently, fundamental demographic data for wild Asian black bears (Ursus thibetanus) in Japan are lacking. As a first step toward science-based management, we must improve our understanding of life history characteristics such as reproduction and mortality. This study aimed to quantify the demographic parameters of Asian black bears in central Japan. (1) By measuring the cementum annuli width of the teeth of females, age at first reproduction was estimated to be 5.44 ± 0.22 (mean ± SE) years and reproductive interval 2.38 ± 0.48 years. (2) By counting placental scars in uteri sampled from recovered bear carcasses, we estimated litter size to be 1.58 ± 0.09 cubs and minimum age at primiparity to be two years. (3) We clarified the annual rates of natural mortality (0.108, 95% CI: 0.064–0.174) and human-caused mortality (0.005, 95% CI: 0.002–0.021) by using capture–recapture records for subadult and adult bears. We used observation data from the first six months after birth to estimate cub mortality rate (0.235, 95% CI: 0.080–0.465). Further research will allow us to identify which endogenous and exogenous factors affect demographic parameters and to use these parameters to estimate population dynamics as a next step.

Noninvasive methods for species identification and dietary profiling from fecal samples in an artificial nest box were developed for the Japanese dormouse Glirulus japonicus. The species is a natural monument in Japan protected by domestic regulations since 1975. We assessed the mitochondrial cytochrome b gene for species identification and obtained location-specific sequences for Oki and Yamanashi, Japan. This marker was able to identify the dormouse species from feces. We also performed DNA metabarcoding analyses to clarify the invertebrate and plant diets of the Japanese dormouse. Various invertebrates and plants were detected, supporting the omnivorous nature of this species. Furthermore, almost all dietary items were identified to the genus level (82.1% and 99.5% for invertebrates and plants, respectively). The dietary components in Yamanashi Prefecture suggested that the Japanese dormouse mainly consumed Lepidoptera and various plants in summer, and Diptera and Hemiptera (aphids) invertebrates and Actinidia sp. plants in autumn. The latter plants produce fruit in autumn, enabling the dormouse to accumulate fat before hibernation. We discuss the potential and pitfalls of the noninvasive method, including the necessity of local DNA databases, reliability of the global DNA database, sampling procedure to avoid contamination, and individual identification.

We studied temporal (monthly and inter-yearly) variations in the dietary habits of wild Japanese badgers (Meles anakuma) inhabiting Ishinomaki City, northern Japan through fecal analyses, focusing on the relationship with the availability of main diets. The diets of the badgers in our study site were mainly composed of three items: fruits, arthropods, and earthworms, which were similar to those in other study sites in Japan. The degree of fruit and earthworm feeding by the badgers was higher throughout the year, whereas arthropod feeding was higher during spring and summer. Vertebrates were less detected in badger feces. During the fall of 2021, the percentage of fruits was greater than that in 2020, while that of arthropods and earthworms showed reverse trends, likely due to inter-yearly difference in fruit availability. For the three predominant food items, no significant correlation was found between feeding and availability. Our results imply that, similar to European badgers, the Japanese badger can be viewed as a generalist animal that uses profitable resources when available but shifts their preference to other food resources when availability of other primary food resources increases.

Human-macaque interactions and conflicts were examined at the main campus of Universiti Malaysia Sabah (UMS). The study observed the behavior of long-tailed macaques (Macaca fascicularis) and their dependence on both natural and anthropogenic food sources. Results revealed that the macaques' diet primarily consisted of young leaves (40.6%) from the natural environment within the UMS campus, but anthropogenic food discarded by students in garbage cans (27.6%) also contributed a major component in their diet. The availability of anthropogenic food positively correlated with the macaques' consumption, indicating that they consumed more of such foods when they were more abundant, particularly during the semesters when students were present. A questionnaire survey further highlighted that while the presence of macaques on the UMS campus was not considered a major concern, it still posed a problem that necessitated immediate attention. The main driving factor behind these interactions, as perceived by the students, was the macaques accessing anthropogenic food waste in garbage cans located in human-dominated spaces. To mitigate conflicts, it is suggested to implement macaque-proof garbage cans, reduce the amount of leftover anthropogenic food, and improve waste management practices. Additionally, educational activities should be considered to discourage direct feeding of macaques by students.

Persistent use of the Mayurjharna forest by elephants led to its declaration as “Mayurjharna Elephant Reserve (ER)” in 2002; however, the usage changed over time. We describe the elephant movement pattern and the quality forage availability in the Mayurjharna ER. We collected past and current sightings of elephants from people and records of the Forest Department and constructed the range used from 1950 to 2018. Initially, the range of elephants in the reserve was ∼80 km² in 1950–1959 that increased to ∼572 km² by 1990–1999 but later decreased to ∼152 km² in 2010–2018. The high human settlements, alteration, and overexploitation of the forest might lead the elephants to the rich agricultural lands outside the reserve, making the reserve just a gateway for elephants to move to other parts of the South Bengal landscape.

Understanding the behavior and ecology of non-native species is important to assess their impact on food webs and ecosystem functions and to facilitate the management of non-native species. The present study reports a case of scavenging on a deer carcass by mammals, especially introduced raccoon dogs and native Japanese weasels, in the World Heritage Site of Yakushima, Japan. A sensor camera was placed near the carcass from March to May 2022 to record scavenging behavior of mammals. Out of at least six species of mammals filmed, raccoon dogs and weasels fed on the carcass. Raccoon dogs almost monopolized the carcass, i.e., raccoon dogs were filmed around carrion more frequently and spent more time scavenging than weasels. Raccoon dogs and weasels were filmed around the carcass at similar times in a day, and no overt aggression was observed between the two species, but weasels were displaced by raccoon dogs. Japanese macaques and sika deer avoided and never fed on carrion. The present study suggests that raccoon dogs contribute to carrion decomposition in the World Heritage Site of Yakushima and that comprehensive studies of carrion availability and the scavenger community could help promote the management of introduced raccoon dogs in Yakushima.

We report the movements related to feeding behavior (using radio telemetry), and the contribution of gut passage to seed germination, of a male masked palm civet Paguma larvata in Sabah, Malaysian Borneo. The 95% kernel and 95% minimum convex polygon (MCP) home-range sizes were 1.20 km² and 2.85 km², respectively, based on 39 telemetry fixes during 151 tracking days. We recorded six feeding sites consisting of fruiting Ficus trees. The civet repeatedly visited the same fruiting trees, indicating specific food resources may be limited within these forests. However, we observed the civet leaving ripe figs uneaten. Thus the total number of ripe fruits might not be the priority factor determining civet feeding behaviors. The tracked civet usually slept in places that were 0.5 km away from feeding sites and he visited several trees in one night. Gut passage enhanced seed germination of a hemi-epiphytic fig species, Ficus lawesii, and ingested seeds germinated much earlier than intact ones, indicating that gut passage may be essential for improving germination. The results suggest the possible contribution of this species to seed dispersal, especially in plants having epiphytic life forms. More studies are needed to evaluate the ecological role of this species in its ecosystem.