To record the behavioral developments of the Japanese giant flying squirrel (Petaurista leucogenys), a nest box with an installed video camera was set on a tree trunk. We observed two nestlings for 73 days since their birth and detected 26 types of behaviors. Among them, eight types of behaviors (‘ride on’, ‘take a balance’, ‘jump with stretch’, ‘bend behind’, ‘spread hindlegs’, ‘stretch a gliding membrane’, ‘groom a gliding membrane’, and ‘pull by forelegs’) have not been reported in other species of Sciuridae. Most of the behaviors appeared around 36 days old (eye-opening age). These behaviors became increasingly proficient and complicated until the 68th day when the young left the nest. Compared with other squirrels, Japanese giant flying squirrels likely need to practice various behaviors for their gliding life during their long nest stage. These results support foregoing comparative studies on behavioral development in Sciuridae, revealing that ground squirrels develop quickly, followed by arboreal squirrels and then the flying squirrels.

We evaluated density dependent effects on pregnancy rate and conception date in sika deer (Cervus nippon) in Hyogo Prefecture, western Japan, as part of a long-term monitoring programme. We collected uteruses, ovaries, fetuses and mandibles from 627 female sika deer captured by hunting and for nuisance control in Hyogo Prefecture from 2003 to 2016. We also measured the body mass of female sika deer when possible. The annual pregnancy rate in adult females during this period was >80%, except in 2004, and did not appear to be dependent on population density. In contrast, the pregnancy rate in yearlings was 15.6% in 2003–2015. Some previous surveys have revealed an approximate 70% pregnancy rate in yearlings during 1988–1998. Non-pregnant yearlings were lighter than pregnant yearlings. These declining pregnancy rates could be caused by light body mass related to population density, which was estimated to be approximately 30 deer/km² in 2010. Intensive population control was conducted subsequently, and the population density gradually declined to 20 deer/km² in 2015, although high population density was still prevalent. Our result of yearling fecundity indicated long-term effects of high population density that have led to an increase in the age at first pregnancy.

To investigate the characteristics of home ranges of Apodemus speciosus, we tracked 17 male and eight female mice using radiotelemetry in an evergreen broad-leaved forest dominated by Pasania edulis and an adjacent Cryptomeria japonica plantation in southern Kyushu. Seventeen and 19 home ranges of males and females, respectively, were estimated by the 95% minimum convex polygon method. Home range sizes and distances between them successively detected during the night became larger during the acorn dropping season, from late September to late November, and one mouse moved approximately 100 m within three hours. Home ranges sometimes overlapped among mice in the boundary area of the two forests. Spatial arrangement and size of home ranges, and movement within home ranges of Apodemus speciosus, varied between individuals. Among them, three mice had home ranges that extended into both forests and nests in the cedar plantation during the acorn dropping season. They constantly moved from the cedar plantation to the broad-leaved forest and vice versa. Such mice are thought to contribute to seed dispersal from the broad-leaved forest to its adjacent conifer plantation.

Pallas’s squirrel Callosciurus erythraeus is a tree squirrel widely distributed in southeast Asia and has been introduced in several parts of Japan. The squirrel is considered a potential avian nest predator based on a few occasional observation records of its egg-predatory behavior. We investigated its significance as an avian nest predator with an artificial nest experiment on Takashima Island, a small islet off the Kyushu mainland, where squirrel density is high. Two each of Japanese quail Coturnix japonica eggs set in artificial nests were lost from 24/25 nests (96%) after three weeks of exposal periods. On all those predated nests, the squirrels were firstly video recorded by infra-red triggered cameras, visiting the nests’ entrances. Jungle crow Corvus macrorhynchos and black rat Rattus rattus, were also recorded on nine nests, but all their visits were far behind the squirrels’ predation events. The estimated average survival time of artificial nests was only 2.7 days, with the average daily survival rate of each nest estimated to be 0.72. Pallas’s squirrel is inferred to be an influential nest predator, due to its characteristic social system allowing the largely overlapping home ranges of individuals and to its very thorough food searching tactics.

We evaluated the observation capability of the GPS-Argos system. GPS positioning data was obtained through the Argos-satellite to track sika deer (Cervus nippon) in Japanese mountain areas. The amount of data sent from forested areas was smaller than that from non-forested areas (mainly farmland). Seven deer with GPS-Argos collars with two-hour positioning intervals of 32–333 days were used for this study. The acquisition rate was 53.1–90.7%. Using only positioning-succeeded data, the rate was 34.1–58.3%. These rates are at similar levels to research conducted outside of Japan. The GPS-Argos system is applicable to deer tracking in Japan, especially for data taken on farmlands during signal communication from the Argos-satellite.

Although dietary compositions of animals are often expressed as average values for sample groups, there is variation even if the average values are similar. We propose an occupancy-rank curve, obtained by arranging the occupancies of a food component from the highest to the lowest values. We used data of the fecal compositions of sika deer Cervus nippon, Japanese serow Capricornis crispus, wild boar Sus scrofa, raccoon dog Nyctereutes procyonoides, red fox Vulpes vulpes, and Japanese marten Martes melampus. There were various types of curves. A pattern of high-value and high frequency was common in sika deer, Japanese serow, and wild boar. Various patterns were recorded in carnivoran species. Food categories of abundant but low quality often showed a pattern of low value and high frequency, while foods of lower abundance but high quality like mammals and birds often showed a pattern of high value and low frequency (L-shaped occupancy-rank curve). Fruits showed a pattern of high value and high frequency in martens’ feces. These patterns of curves reflected the food availability and needs of the animal side. We discuss the characteristics of these curves and recommend their use.

An individual of Laxmann’s shrew (Sorex caetutiens Laxmann, 1788) with completely white pelage was captured on 5 December, 2011 in Hamanaka-cho, Hokkaido, Japan. It was captured alive by a house cat and kept in a cage until it died on 12 May, 2012. It is the first record of S. caetutiens with a completely white pelage in Japan. Owing to its pinkish skin and iris, it seems to be albinistic rather than leucistic, although the gene causing the white pelage has not been determined yet. This specimen (skin, skull and bodies in ethanol) was tentatively deposited at the Institute of Low Temperature Science, Hokkaido University.

In October 2017, we conducted harp trapping based on witness information of bat species at a school in Amami-Oshima Island, Kagoshima, Japan, and captured two male bats. These bats had different morphological features from other bat species known to inhabit the island, and were considered to represent an unrecorded species. These bats were similar to H. alaschanicus; however, we could not identify the bats to specific species. Echolocation call types of captured individuals was FM-QCF pulse with a mean peak frequency of 35.35 kHz, and unknown bat species flying on the coast of southeastern Amami-Oshima Island also showed the same mean peak frequency. This result suggests that the captured bats and the unknown flying bats are the same species.

We report the discovery of bones and body-parts of the endemic grass lizard Takydromus toyamai from non-native Japanese weasel Mustela itatsi feces collected on Miyakojima and Irabujima in the Miyako Islands, Ryukyu Archipelago, Japan. The results are suggestive of the cause of the recent serious population decline in this endangered lizard species, and are further evidence of predation on indigenous terrestrial animals of this archipelago, including those of rare and endemic species, by introduced M. itatsi.

In the 1920s, Japanese mammalogists became active collecting specimens, describing new species, and clarifying the fauna in Japan’s overseas territories, as a result of the imperialistic territorial expansion of the Empire of Japan to East and Southeast Asia and the South Pacific. At that time, the taxonomy and biogeography of mammals in Japan developed rapidly and reached its golden age. In the background, zoology in Japan developed after the Meiji period and Japanese mammalogists started to investigate many taxa using various methods. Also, a number of universities and research institutes of biology were established in provincial cities; for example, the first research laboratory of mammalogy was set up in Taipei Imperial University. The first mammalogical society was settled in 1923; however, the society became less active after the passing away of Prof. Shozaburo Watase in 1929. In this article, we provide a brief history of the mammalogical society from its beginning to its end, especially focused on the two outstanding pioneer mammalogists, Nagamichi Kuroda and Kyukichi Kishida, who led Japanese mammalogy in that period.

This manuscript was prepared as supplemental information on the late Dr. Kyukichi Kishida, who was a pioneer in “Japanese independent mammalogy,” as described in detail by Shimoinaba and Yasuda (2018). He studied Taiwanese mole species in the 1930’s as examples of the biogeography of Taiwanese mammals. He recognized Mogera insularis (Swinhoe, 1862) and at most two distinct species on the island, and compiled them and some other closely related mole species found on the southeastern part of the Asian Continent into a new genus distinct from Mogera, without description of species nor genus. Although these taxa are considered as nomina nuda, recent morphological and genetic research indicates the possibility that they may correspond to one distinct species of mole, i.e. Mogera kanoana Kawada et al., 2007, including a genetic variety of M. kanoana in Taiwan. A new genus may also be supported by distinct trends in karyological evolution shown in the M. insularis group (M. hainana, M. insularis and M. latouchei). Kishida’s predictions on the taxonomy of Taiwanese moles are thought to be well applicable.