Individual and sexual variations in the behavior of Asian black bears (Ursus thibetanus) are important in understanding their frequent inhabitation of human-dominated lands. In this study, we assessed individual and sexual variations in the selection of Japanese oak (Quercus crispula) forest, forest dominated by hard mast trees, and residential and agricultural areas by bears in fall. Bears selected Japanese oak forest, and avoided residential and agricultural areas in moderate and poor mast years. Other hard mast forests were selected in poor mast year but were avoided in moderate mast years. Large individual variation in the selection of Japanese oak forest and other hard mast forests in the moderate and the poor mast year while sexual variation was not significant. Additionally, individual variation during the poor mast year was greater than in the moderate mast year. Individual variation in habitat selection increased based on hard mast abundance.

Winter activity of the Japanese badger (Meles anakuma) was examined using camera traps from December 2016 to March 2017 in Kagoshima City, southern Kyushu, Japan. Two badgers used the same sett in winter, and their activities outside the sett occurred synchronously. The start of winter lethargy is likely caused by external photoperiods rather than low temperatures. Night-time activity duration was, remarkably, reduced from late December, after which badger activity was intermittent until early March. Badger activity occurred regardless of any fluctuations in ambient temperature, even when the temperature dropped to 3 or even 0°C. Periods of inactivity outside the sett which exceeded three days occurred on average every 11 days. This periodicity was estimated by the calculation of autocorrelation coefficients. The hibernation period lasted 50 days from 5 January to 5 March when activity ceased for more than three successive days. Hibernation periods in Kagoshima City (32°N) at low latitudes were shorter than those of badgers inhabiting the higher latitudes of Hinode Town, Tokyo (36°N) and Yamaguchi City (34°N).

Although populations of Japanese squirrels (Sciurus lis) are generally limited in size in urban areas with heavily fragmented forests, habitat use by this species is still reported in very small forests (<1 ha) in Morioka, Iwate Prefecture, Japan. However, it is not clear whether these squirrels move around between forest patches. To clarify the status of Japanese squirrel populations inhabiting small urban forests, we radio-tracked ten squirrels from May 2016 through November 2017, focusing on their movement between forest patches in the fragmented landscape of the northern urban fringe of Morioka City. We observed 47 inter-patch movements by six squirrels. Movement between forest patches divided by orchards was observed 21 times in three individuals, whilst movement between patches connected by roadside trees was observed 18 times in two individuals. Movements between forest patches divided by arterial roads were observed only 5 times and in only one individual. These results suggest that squirrels within the study area use several forest patches and that squirrels can move more easily between forest patches connected by roadside trees or orchards which may function as corridor habitats. Forest patches divided by arterial roads likely have low habitat connectivity.

Fifteen studies on the food habits of the raccoon dog (Nyctereutes procyonoides) were reviewed in order to ascertain the types of fruits that are preferred by raccoon dogs. A total of 103 fruit species have been suggested, among which as many as 68 species, including 2 gymnospermous tree fruits (Ginkgo biloba and Torreya nucifera), were fleshy fruits. The fruit of Hovenia dulcis is morphologically a drupe, but the pedicle swells, and tastes and smells sweet, thus, functioning as a “fleshy fruit.” Three seeds such as Ophiopogon japonica look like fleshy fruits. The other 30 species were dry fruits. The fruits of 70 species (68.0%) were colorful and 57 species (55.3%) were small (<10 mm in diameter), suggesting that these typically bird-dispersed fruits are also preferred by the raccoon dog. Ten species of large and dull-colored fruits were noted, and Ginkgo biloba was consumed at high frequencies. As many as 21 cultivated plants were recovered from the raccoon dog foods, which seems to be characteristic to the raccoon dog. This review showed that the raccoon dog feeds on many small and colorful bird-dispersed fruits as well as large and dull-colored fruits such as G. biloba and Diospyros kaki.

The Asiatic black bear (Ursus thibetanus) is a critically endangered species in Kanagawa Prefecture, Japan. We investigated the distribution of Asiatic black bears in the southwestern part of the prefecture, where systematic surveys have not previously been conducted. We set up 15 automatic cameras between May and October of 2017 (2,122 camera-days) in the Hakone Nature Forest of Tamagawa University, which is located close to the borders of Hakone and Yugawara. Bears were documented on 10 occasions at six sites, providing the first reliable record of bears in the southern part of Hakone and Yugawara since 1945. In addition, bears were recorded in all months except May and August, indicating that they use this area continually and are not transient. Furthermore, it was possible to identify unique individuals from their physical features, and we identified at least three unique individuals using this area. Thus, it is likely that a population of Asiatic black bears inhabits this region. To manage the bears effectively in the prefecture, it is necessary to continue monitoring the bear population in this area.

This Special Report focuses on the ethical regulations and guidelines in wildlife research involving the capture of deer species, bears, primates, and medium-sized mammals. The paper is a report on the workshop “Ethical issues concerning wildlife research in Japan and its perspective” held at the Toyama conference of the Mammal Society of Japan in September 2017. We present the current domestic problems and prospects pertaining to the four animals mentioned above.

In the past few decades, the number of studies performed on invasive alien species has outnumbered that on native mammal species. The trapping of medium-sized mammal species has been widely carried out for various purposes, including for the deployment of radio-tracking collars for determining the home range of native species and for the eradication of invasive species. There is always a risk of accidentally trapping non-target animals; therefore, technicians need to be knowledgeable, skilled, and familiar with the immobilization and physical restraint techniques for various species.

The AVMA Guidelines on Euthanasia have indicated that it is of utmost importance to minimize the amount of human contact during handling procedures, particularly for free-ranging wild animals. The AVMA also highlights the importance of stress management for personnel, who may be subject to public exposure and under substantial pressure, especially with respect to animal euthanasia.

The ultimate mission of a mammologist is to explore the life history of wild animals and apply the acquired knowledge for effective wildlife conservation. To achieve this goal, it is our social responsibility to logically and practically inform the public about the appropriate techniques and necessary research involved.

The Primate Society of Japan established its primate ethics policy in 1986 as the “Guiding Principles for Animal Experiments Using Non-Human Primates”. In 2013, the “PSJ Guide Lines for the Care and Use of Laboratory Non-Human Primates” was formulated and announced. Subsequently, the development of guidelines for rearing non-human primates for breeding and experimental use advanced, but the formulation of wildlife research guidelines did not proceed at an equal pace. The reason for this is that there are many types of primates, such as apes, cercopithecoids, capuchins, colobuses, and prosimians, and bioethical standards vary according to the target species. The International Primatological Society and the American Society of Primatologists have published the “Code of Best Practices for Field Primatology”. At the Primate Society of Japan, preparations are underway for the publication of the “Ethical Guidelines on Field Studies of Primates”, and the formulation of ethical guidelines by the Mammal Society of Japan is urgently needed.

Recently, hands-on study methods for bear species have become more popular in Japan, and hence the ethical burden for animal welfare has increased. However, we have not yet ensured the necessary guidelines or protocols for bear studies in Japan. In this article, I introduce certain advanced cases from North America and Scandinavia, to initiate discussions about these issues as the first step.

Many sika deer researchers obtain their research materials from hunting or management activities. Given the current situation, the ethical considerations of using deer in research should be augmented by referring to the general principles of the humane killing of wildlife in foreign countries. The “AVMA Guidelines for the Euthanasia of Animals” include a section on free-ranging wildlife. The distinctive point of this section is the view that “the quickest and most humane means of terminating the life of free-ranging wildlife in a given situation may not always meet all criteria established for euthanasia” and “the best methods possible under the circumstances must be applied, and new technology and methods demonstrated to be superior to previously used methods must be embraced”. Thus, we should not merely imitate overseas guidelines or regulations, but examine and innovate the most humane measures and techniques to adapt to Japan-specific social conditions, institutions, and regulations.

In Japan, “Honyu-doubutsu” or “Honyurui” has been used to refer to mammals, but only the latter has been adopted as a taxonomic word. The present study describes the history of the second stage in Nihon Honyu-dobutsu Gakkai (=Mammalogical Society of Japan) that began in 1949 and Honyurui Kenkyu (=Mammal Research) Group that started in 1963, as well as their prehistory, and how and why the two organizations were joined together as Nihon Honyurui Gakkai (=Mammalogical Society of Japan). The following sources were used for describing the history: articles, records, and opinions that appeared in Honyu-dobutsu-gaku Zasshi (=Journal of the Mammalogical Society of Japan), Honyurui Kagaku (=Mammal Science), and Doubutsugaku Zasshi (=Zoological Science) together with other periodicals, books, etc. The first stage of Nihon Honyu-dobutsu Gakkai was formed as Nihon Dobutsu Gakkai (=Zoological Society of Japan) in 1923 but dissolved around 1929, after the death of Shyo-zaburou Watase, the President of the Society. After Word War II, following Honyu-doubutsu Danwakai (=Mammal Seminar) which was organized between 1946 and 1949, the second stage of Nihon Honyu-dobutsu Gakkai was organized in 1949. However, Nezumi Kenkyu (=Murid Research) Group was created in Nihon Dobutsu Gakkai in 1955 and the name was changed to Honyurui Kennkyu (=Mammal Research) Group in 1963 to highlight the mammalogical research for postgraduate students. Therefore, the society and group originated from Nihon Dobutsu Gakkai although they were formed in different years. Since members overlapped between the two organizations immediately before the reestablishment of Mammalogical Society of Japan (third stage), most hoped for improved management and costs, as well as research activities in the society.