Genetic characteristics of the poorly known Kyushu population of Asiatic black bears (Ursus thibetanus), were investigated using mitochondrial DNA (mtDNA) analysis of the “bear’s hands” stored by the Fujino and Sato families at Takachiho, Miyazaki Prefecture. The mtDNA control region (648 bp; haplotype: KU01) was successfully analyzed in the Sato family-derived sample that, according to in-person interviews, was presumed to have resulted from a capture in the Sobo Mountains during the mid-Meiji and early-Taisho eras. Along with the previous data, these results suggest that the allegedly extinct Kyushu population may have formed a unique local population that was genetically distinct from other bear populations in Japan

Asiatic black bears (Ursus thibetanus) feed on acorns, such as Quercus crispula and Q. serrata, to store fat during autumn. However, tannins, astringent polyphenols, contained in the acorns are known to have negative effects, such as reduction in protein digestibility and gastrointestinal tract failure, on acorn consumers and it is unknown how the bears respond to tannins.

We analyzed the parotid gland of black bears and found that they were capable of secreting proline-rich proteins (PRPs), which belong to a group of tannin-binding salivary proteins. Black bear PRPs contained 25% proline and their relative affinity to tannins extracted from Q. serrata was thirteen times higher than that of bovine serum albumin. The parotid glands of black bear were hypertrophied in autumn, and the PRPs concentration in the parotid glands increased at the same time.

Wild boars (Sus scrofa) have been spotted since 2007 in various parts of Iwate Prefecture, Japan. We clarify the process of their distributional expansion and predict the probability of their future appearance using a species distribution model. After the first sighting in Oshu City in 2007, the number of sightings increased mainly in the southern part of the prefecture in 2011, and wild boars were seen throughout the prefecture in 2018. Crop damage from wild boars was first observed in 2012 and increased from 2014 to 2017. Based on these results, we propose that 2007–2010 was the immigration period, 2011–2017 was the expansion period, and 2018 or later was the established period for wild boar in Iwate Prefecture. We found that elevation, vegetation, and land use data were effective predictors of the probability of appearance of wild boars. We predicted the probability of appearance using data up to 2017 and compared it with actual appearance sites in 2018 and 2019; we confirmed that the sites with higher predicted probability actually appeared. In the future, the number of boars would increase from areas with a high probability of appearance, and boars would appear in these areas.

A soil-transmitted nematode, Strongyloides callosciureus, is an exotic parasite introduced into Japan along with the spread of an invasive host, Pallas’s squirrel Callosciurus erythraeus. The establishment of this parasite has so far been reported from several localities in Shizuoka and Kumamoto Prefectures, but basic information for risk assessment is not fully available in other host-colonized areas. Here, we report the infection status of this parasite in suburban areas (i.e., Yokohama, Yokosuka, Kamakura, and Bando Cities) in the Kanto region, where the host squirrel has already invaded. A total of 124 host individuals, captured in 2016, 2018, and 2019, were examined. Parasite infection was found only in Yokosuka City, with a low prevalence (13.33%) and low mean abundance (0.40 worms per host examined) and mean intensity (3.00 worms per host infected). This suggests that in the examined areas, infections are infrequent or that the parasite itself is absent. In addition, partial sequences of the 18S and 28S rDNA regions, examined for all the parasite individuals, showed the highest homology with S. callosciureus from Hamamatsu City, with values of 99.93% and 100.00%, respectively.

The wild boar (Sus scrofa) is one of the most widely captured animals in Japan, and the population culled using leg snare traps has been increasing in recent years. However, the characteristics of wild boars captured using this method remain unclear. This study was conducted to determine the sex ratio and age structure of the wild boars captured in the Yamizo mountainous region of Tochigi Prefecture for many years by examining the wild boars brought to a slaughterhouse in Nakagawa town. The male-to-female ratio was 1.37:1. To determine the age structure, the number of animals, including both males and females, in the 0-year-old group was low. In contrast, 83.9% of males were <2 years old, whereas 37.2% of females were ≥2 years old. Additionally, the age at which the probability of capture, calculated from this sample, was the highest, and was estimated to be 1.4 years for males and 2.1 years for females. As female wild boars attain sexual maturity and start breeding in less than one year of age, continuous capture of subadult or older female boars using leg snare traps is effective in controlling the population of wild boars.

We recorded a Japanese marten biting the neck of a wild boar piglet, using an infrared-triggered camera installed in the forest in Gifu Prefecture, Japan. It is unclear whether Japanese martens actively capture wild boar piglets as a food resource, but we propose that Japanese marten as a potential predator of wild boar piglets.

An exchange meeting of mammal research for students and young researchers, “Mammal Research Seminar,” was held online in August 2020, although many conferences and seminars were canceled because of the COVID-19 pandemic. We reported the merits and demerits of online exchange meetings with the background and details of this meeting. Compared with meeting in person, online meetings have difficulty in interacting with other participants, and there is a high risk of data breach. However, some merits, such as attracting new participants and activating question-and-answer sessions, were observed. Online meetings such as this could increase in future due to restrictions on in person activities, making organizers think about organizing online seminars and the related aspects. We hope that this report will contribute to other group activities.

The Japanese serow (Capricornis crispus) has well-developed preorbital glands and rubs them frequently on leaves, tree trunks, and twigs. To clarify the function of such behavior, we examined monthly changes in scent-marking frequency by direct observation of serow behavior in a 100-ha study area in the Shimokita Peninsula, northern Japan, on 435 days between July 1979 and August 1986. The author has previously investigated scent-marking frequency according to season and found that adult males scent-mark more frequently than adult females. Both sexes scent-mark throughout the year, with higher frequencies in the autumn rutting season and lower frequencies in winter; however, juveniles rarely marked. The present results, considered alongside unpublished data, confirmed these findings and showed that the frequency of such marking by adult males was 2.5 times higher than that by adult females. Furthermore, the present study revealed that 1) the frequency of marking by both sexes was higher not only in autumn but also in spring; 2) the increased frequency of scent-marking in autumn was more conspicuous for adult males than for adult females; 3) both sexes showed the lowest marking frequency in February; and 4) kids aged ten months exhibited marking behavior for the first time in March.

Nest boxes (43 pairs) were set on tree trunks at heights of 0.5 m and 1.8 m above the ground in a larch forest at Mt. Yatsugatake, central Japan in May, 2013. The use of the nest box by small mammals and the nest materials brought by them were determined four times in 2013 and 2014. Approximately 27.7% (101 out of 364) of the nest boxes were used. Most of the boxes (93.5%) were used by the Japanese dormouse (Glirulus japonicus), and a few boxes were used by the small Japanese field mouse Apodemus argenteus. The use rate was particularly high (40%–50%) in September, after the rearing season. Boxes at higher height (1.8 m) were used more frequently than boxes at lower height (0.5 m). The dormice used mosses, beard lichens, and barks. For each nest, a particular material was predominant, and others occupied small portions.

Regression analysis is a statistical method that attempts to quantitatively explain the variation in a dependent variable using the variations in independent variables. Regression analysis has three objectives: describing the associations between the dependent variable and independent variables, predicting the value of the dependent variable, and estimating the intervention effect of an independent variable on the dependent variable. However, Japanese mammologists are behind the curve in understanding the criteria for selecting independent variable to achieve the objectives of regression analysis. In addition, not only is the mean of a population of considerable interest but also the individuals that deviate from the mean. To date, regression analyses that focus on conditional expectations have been unconsciously adopted by Japanese mammologists. This study provides an overview of the dependent variable selection procedures for regression analyses with three analytical objectives. We further show the potential for introducing a quantile regression analysis method that would enable researchers estimate the conditional quantiles of a distribution of dependent variables in a linear model in mammalian studies.