Mammal Study

The Japanese marten (Martes melampus) invades houses through holes and causes excrement problems. These holes should be covered to prevent the marten's intrusion into houses. However, there is no information about what size of hole they can squeeze through. Therefore, we investigated the sizes of the holes that they could pass through using three reared individuals in summer and winter. We put a bait in an experimental box with a replaceable front panel, which had a square or round hole. The minimum passable sizes were recorded in summer. For a square hole the minimum size was 5.0 cm for each side, and for a round hole the minimum sized hole had a diameter of 5.5 cm. It is necessary to cover holes of these sizes or more to prevent their house invasion. The body weight and the hole shape had no significant effect on the minimum passable area. On the other hand, the season had a significant effect on the minimum passable areas. The shoulder seems to be the limiting factor for whether the martens can pass through the holes. Therefore, the seasonal change in the body size around the shoulder may affect the minimum passable area of holes.

Many heterotherms employ torpor to conserve energy to cope with food shortage. Food shortage affects not only energy budgets but also other aspects of nutritional status. In addition to serving as an energy substrate, dietary proteins also provide vital nutrients including essential amino acids, some of which cannot be synthesized de novo. We evaluated the hypothesis that dietary protein deficiency induces torpor as a means of adjusting protein metabolism in the African woodland dormouse (Graphiurus murinus), a rodent with a protein-rich diet and lacking a cecum, which limits the potential for hindgut fermentation and coprophagy. Dormice were fed control and non-protein diets with equivalent energy content every two weeks under thermoneutral conditions. While the dormice did not express torpor under control conditions, some did under protein-deficient conditions. Among dormice expressing torpor, one maintained energy intake comparable to that during the control diet period, whereas the other reduced energy intake due to spontaneously reduced food consumption. These results suggest that torpor can be induced directly or indirectly by dietary protein deficiency even in the absence of energy constraints and thermal stress. In either case, torpor in response to deficiency in certain nutrients can reduce demands of the nutrient.

Wolves play a crucial role in shaping ecological communities as an apex predator in the dry-open forests of semi-arid landscapes in India. Large scale habitat loss pertaining to human expansion and retaliatory killing by human caused severe decline in the wolf population across its range. The estimated wolf population size is close to 2000–3000 individuals in India; however, these estimates were decades old and the present status of the wolf in the semi-arid landscape is largely unknown. We assessed the distribution of wolves in Kailadevi Wildlife Sanctuary, Rajasthan using occupancy models and identified important factors associated with habitat-use by wolves. Occupancy modelling shifts the focus from individual animal to a site, while accounting for detection probability. To assess the habitat-use we used sign-based surveys that rely on data collected from adjacent sampling sites (replicates). The habitat-use was assessed across 672.82 km² surveying 48 grid cells, each measuring 14.44 km². Estimated habitat-use Ѱ (SD) was found to be 0.82 (0.14). Our findings suggested that availability of agriculture land had the significant positive influence on the habitat-use of wolves. Other factors such as availability of water, scrubland, and wild prey (nilgai and chinkara) also had a positive effect on the habitat use of wolves, but it was not significant. Forest cover has a negative influence on the habitat use of wolves. This study is the first rigorous assessment of the Indian grey wolf habitat-use at the level of wildlife reserve with potential conservation value that can be applied to other areas in India.

We studied the autumn (September–November) food habits of the raccoon dog (Nyctereutes procyonoides) by sampling the stomach contents of 64 individuals (male, n = 31; female, n = 33) killed on national roads in Ibaraki Prefecture. Our aim was to examine sex differences in the autumn food habits of raccoon dogs in suburban area where human related disturbances can occur on the raccoon dogs. The frequency of occurrence (FO) and the percent volume (PV) of fruits and insects were high for both males and females and FO and PV of garbage were low for both males and females. There were no significant differences between the sexes for food items. FO and PV were not significantly different between sexes for adults and yearlings. This is likely because males and females may use the same area even in suburban area, and they likely both forage on the most abundant food resources that are easily accessible within their habitats.

The diel activity pattern is a key factor in the coexistence mechanism of sympatric wild animals, enabling temporal niche partitioning. Although previous studies on sympatric ungulates (sika deer, Japanese serow, and wild boar) have reported dietary and spatial niche partitioning, temporal niche partitioning in these sympatric ungulates is not well understood. In this study, we aimed to elucidate the seasonal diel activity patterns of three sympatric ungulates in Gifu Prefecture, Japan, where they have been sympatrically distributed since 1978. We placed 21 camera traps from August 2017 to November 2019, and investigated diel activity patterns and photographic frequencies over three time periods (daytime, night-time, and twilight). Although we found no seasonal changes in diel activity patterns of three ungulates, but patterns showed differences among species. While sika deer showed crepuscular activity, wild boars and Japanese serows showed nocturnal activity. In addition, Japanese serows showed temporal niche partitioning against sika deer. Consequently, we suggest that the relationship between sika deer and Japanese serow is competitive in terms of diel activity patterns.

The Hainan mole Mogera hainana was described as a full species by Thomas ( 1910 ), but its taxonomic status of this animal has been debated since then and remains controversial. In this study, we determined the mitochondrial genome of M. hainana. We also estimated its phylogenetic relationships using mitochondrial Cytb and nuclear Rag1 genes and conducted molecular species delimitation analyses using Bayesian Poisson tree processes, Automatic Barcode Gap Discovery, and Assemble Species by Automatic Partitioning to determine the evolutionary position and putative taxonomic status of M. hainana. The mitogenome of M. hainana is 16 845 base pairs, composed of 13 protein-coding genes, 22 tRNAs, two rRNAs, and the control region. We further compared this sequence with those of other Mogera species. The phylogenetic trees support a sister relationship between M. hainana and M. kanoana and close relationships among M. hainana, M. kanoana, M. insularis, and M. latouchei. Species delimitation analyses suggest that M. hainana is distinct from other recognized species and thus is likely a distinct species.