Siberian chipmunks, Tamias sibiricus, exhibit hibernator and non-hibernator patterns as intra-specific variation in hibernation, which has the potential to elucidate the hibernation regulation mechanism.

Siberian chipmunks, Tamias sibiricus, have hibernator and non-hibernator as intra-specific variation in hibernation style, which has the potential to elucidate the hibernation regulation mechanism. However, there are no reports of the breeding protocol under laboratory conditions and success of planned breeding, which is a major obstacle in developing a model animal for hibernation. In this study, we observed the female vagina and estrus call, and compared whether there is a difference in breeding season period or estrus call between the hibernators and non-hibernators. Copulation behavior was observed when mating experiments were performed during the period of estrus call, and then, we clarified the significance of the estrus call on an estrus cycle using a vaginal smear. Results showed that female chipmunks have a single breeding season in a year. The estrus call was observed four or five times in a cycle of approximately 11 days. The estrus call was closely related to the increase in keratinized cells in vaginal smears, i.e., the estrus call is an important signal indicating ovulation in the estrus cycle. There were no differences in the length of breeding season and the estrus call between hibernators and non-hibernators. We attempted mating between hibernators and non-hibernators and succeeded in creating an F₁ generation.

We observed the three bat species Tadarida insignis, Pipistrellus abramus, and Vespertilio sinensis at joint surfaces of a railway viaduct of the Kyushu-Shinkansen train in Yatsushiro City. In addition, one echolocation call was recorded, which is characterized by 36 kHz (peak frequency) on average, and differs from that of other species that occur in the Kyushu District. Dense clusters of hibernation colonies of T. insignis were observed for the first time. A V. sinensis colony was also observed first in Kumamoto Prefecture. T. insignis and P. abramus formed maternity colonies in July. The slits of the hibernating site were narrow, with a width of about 3 cm. The population size of T. insignis peaked once in May and once in October, whereas that of P. abramus peaked only in September. Emergence time of the first bat was about 22 minutes after sunset in P. abramus, and 36 minutes after sunset in T. insignis. T. insignis fed mainly on Lepidoptera, Hemiptera, Diptera, Neuroptera, Coleoptera, and Odanata, and the respective proportion fluctuated seasonally; agricultural pests were also included in the diet. Surveying structures such as viaducts is thus useful to assess occurrence and biology of different bat species.

To study female behavior during breeding, we set up three nest boxes equipped with a camera box in the suburban forests of Hachioji, Tokyo, Japan and recorded their behavior. We recorded 10 cases of breeding during 3549 days from February 2010 to May 2014. Females gave birth in two peaks, from February to March, and from June to September. The average litter size was 1.3 individuals. In three out of 10 cases, pups grew until they went out from the nests, and in three cases they were predated upon by a snake and a marten. Reproductive success for the remaining four cases were unknown due to reasons such as nest movement. Females stayed in the nest for most of the time till a few days after birth. As the pup grew, the time spent outside the nest increased. The activity patterns of females in rearing pups differed among individuals. Females and their offspring stayed together until 229 days of age of the pup at the longest. It was suggested that time investment for breeding was higher in female Japanese giant flying squirrels than in other species of Sciuridae.

Crop damage by Japanese macaques (Macaca fuscata) is a frequently occurring problem in Japanese agriculture. The traditional rural landscape “Satoyama” comprises a mixture of farmlands and forests, where macaques and humans coexist. We used camera traps to examine macaque habitat use in Satoyama regarding differences between vegetation types and over time. Macaques were monitored using eight camera traps with infrared sensors, which were set up on an abandoned fruit farms, in a Castanopsis–Quercus secondary forest (here termed ‘secondary forest’), on a Cryptomeria–Chamaecyparis plantation (termed ‘plantation’), and in a bamboo forest. The abandoned fruit farm and the bamboo forest were used as foraging sites. The abandoned fruit farm was predominantly used in the morning, and macaques fed on leaves and fruits. The bamboo forest was more likely to be frequented in the afternoon, and there, macaques fed on crabs and frogs collected from a local stream and on fruits carried from the abandoned fruit farm. Adult macaques were predominantly observed on the abandoned fruit farm and in the bamboo forest, whereas subadult individuals occurred more frequently in the secondary forest and on the plantation surrounding the abandoned fruit farm and the bamboo forest. These results suggest that the spatial structure of plant community is an important factor regarding habitat choice by Japanese macaques in Satoyama.

The applicability of localized management, a relatively new method for deer management, was determined through investigation of genetic structure and maternal analysis using microsatellite markers of wild populations of sika deer (Cervus nippon). A total of 251 individuals (including 63 fetuses) captured in four populations (Hokkaido, Shizuoka, Gifu, Miyazaki) were used for microsatellite DNA genotyping of 17 loci. Calculation of the probability of identity between siblings (PID-sibling) indicated that four of the most heterozygous loci in our data sets were sufficient to distinguish individuals. Most of the results from the software STRUCTURE showed the genetic structure among populations. However, we did not detect maternal groups within each population. In the maternal analysis performed using 63 fetuses, the probability of estimating a true mother who was pregnant with a fetus was only approximately 20%. We concluded that it was not appropriate to apply localized management to sika deer populations, not even in the case of the Shizuoka population, which has the largest population size. It appears that the past bottlenecks in the Japanese sika deer populations have led to a reduction in microsatellite marker polymorphisms.

We used a spatially explicit capture-recapture model to estimate the population density of the Japanese dormouse Glirulus japonicus in Nagano Prefecture, Central Japan. From May to October 2014, resting G. japonicus were captured from nest boxes (n = 297) installed in the region, and individually identified. Of the 37 males captured, 5 were recaptured individuals; while 10 of the 34 captured females were recaptured. The population density estimates for the dormouse were 1.93 ± 0.35 individuals/ha (mean ± SD) overall, 0.65 ± 0.25 individuals/ha for males and 3.32 ± 1.27 individuals/ha for females. The female population density estimate was extremely greater than the male population density. The home range sizes of the dormouse were 3.42 ha in total, 3.96 ha for males and 0.98 ha for females. The estimates from the present study should not be generalized; however, after obtaining the population density estimates for the Japanese dormouse in other areas, comparisons between areas would be informative.

Expanding populations of sika deer (Cervus nippon) have presented new threats to native biodiversity conservation. Presently, their populations are expected to reach the heavy-snow regions in northern Japan, which were once thought as unsuitable habitat for the species. As there is a fast-growing demand for precautionary measures against the further expansion of deer, we developed two population monitoring techniques using ecoacoustics during the rut: active acoustic monitoring (AAM) and passive acoustic monitoring (PAM). This review aims to highlight the advantages of and challenges remaining in both techniques through comparison with the traditional monitoring methods. The AAM is a playback survey and is attained from behavioral features of adult male deer, i.e., vocal responses that can be elicited by audio playbacks. The current PAM enables a new method of monitoring the distribution changes of deer with a lag-phase of population increase by detecting loud deer-calls using autonomous recording units and a machine learning algorithm. Both methods showed higher detection rates of deer compared to the existing methods. In particular, the PAM system has a high potential value to promote large-scale population monitoring of deer because of its large detection area and user-friendliness supported by semi-automated detection procedures.

The food habits of raccoon dogs (Nyctereutes procyonoides) in non-urban areas were studied via fecal analyses. Artificial materials appeared infrequently (5.0%), with only 0.4% mean occupancy. Fruits (frequency 98.0%; mean occupancy 30.0%) and seeds (frequency 93.1%; mean occupancy 25.7%) were the most important food sources. In spring (April and May), fruit, seeds, and insects each accounted for about 20% of the diet. In summer (June to September), the proportion of seeds increased to 36.7%. In autumn (October and November), the proportion of fruit increased to as high as 71.5%, while that of insects decreased to 0.8%. In early winter (December and January), the proportion of fruit decreased to 43.2% and that of seeds increased to 31.7%. In late winter (February and March), fruit (15–35%), seeds (15–25%), and insects (20–30%) were all important. There was a seasonal pattern in seeds consumed: Celtis sinensis in late winter, Rubus spp. in spring, Cornus controversa in summer, Hovenia dulcis in autumn, and Morus australis in winter. The use of Morus australis and Actinidia arguta did not correspond to the fruiting seasons.

We recorded long-distance movement of a sub-adult female Asian black bear (Ursus thibetanus) during summer. The two-year-old individual left its natal home range on May 30, 2012, and had not returned by the time tracking was terminated on August 29, 2012. During this 91-day period, the bear travelled a total of 323.56 km and had covered a 95% minimum convex polygon home range of 457.95 km². The home range size of this individual was remarkably large compared to that of 14 other bears captured in the same area (3.50–332.40 km²). The two-year-old female bear had moved across the area of the Bear Management Unit, and it crossed two different national roads after 9 and 23 days, respectively. The observed movement behavior of this bear may be an effect of natal dispersal.

The Tokunoshima spiny rat Tokudaia tokunoshimensis is an endemic species in Tokunoshima Island, southern Japan, and an endangered species. However, records and data on the distribution of this species are extremely limited. The objective of this study was to determine the current status of the Tokunoshima spiny rat, to assist in the establishment of conservation measures. We incorporated a broad field survey from 2011 to 2015 and examined collection records for Tokunoshima Island until 2016. This study identified core habitat areas for the Tokunoshima spiny rat around Mt. Amagi-dake, Mt. Inokawa-dake, and Mt. Inutabu-dake. We also identified areas where there are no records of the Tokunoshima spiny rat since 2006.

Young researchers, such as post-doctoral who interested in mammalogy, joined the Mice Research Group (Nezumi Kenkyu Group) in 1958. The name of this group was changed to the Mammal Research Group (Honyurui Kenkyu Group) in 1963, and the group progressed through free discussion and mutual criticism among the members. During the period of great change in social and political systems after WWII, young researchers of the Mammal Research Group grew up with the advice of their supervisors. The main activities of the group were organizing symposia, free discussion in annual meetings, description of each mammal species in Japan, and the project of publishing a guidebook of mammalogy. As the group membership increased rapidly in the 1980’s, the expectations of members became diversified. Then, to better manage the organizations, the consolidation of the Mammal Research Group and the Mammalogical Society of Japan was proposed. The members who advocated the consolidation were in the majority, and the Mammal Society of Japan was established in 1987, with the merger of the two organizations.