The Iriomote cat, Felis iriomotensis, is a small felid endemic to Iriomote Island, Okinawa, Japan. Little is known of its breeding ecology in either captivity or the wild. In this study we investigated the reproductive cycle from observations of the frequency of male urine marking, reproductive conditions and behaviors of females with young in the field, and with reference to previous reports related to breeding. Breeding of female Iriomote cats may not be seasonally restricted, although a mating peak was recognized between February and April. Females delivered litters between April and June, and maternal care continued until kittens reached four to 4.5 months of age.

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The dark red-backed vole Clethrionomys rex is widely distributed in Hokkaido and on the adjacent islands such as Rishiri and Rebun, Japan. In Hokkaido, the vole species is recorded from the Kitami and Yubari mountains, the Shiribeshi Volcanic Plateau, the Youtei Volcanoes, and the Oshima Mountains, as well as from the Daisetsu, Hidaka, and Teshio mountains. This species occurs in wooded, montane areas ranging from 20 m to 1900 m in altitude in Hokkaido, whereas it commonly occurs in various habitats on the islands of Rebun and Rishiri.

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Intercolonial migrations of mother-infant pairs in Rhinolophus ferrumequinum nippon were investigated during the summers of 1984 and 1985 by the banding-recapture method in the Izumo mines, Ishikawa Prefecture, Japan. About 50% of all lactating females migrated with their infants among several nursery colonies, and the nursery colonies were closely interconnected with each other through interchanges of mother-infant pairs. Emigration of mother-infant pairs increased with larger creche size (the term ‘creche’ referring to the infant cluster formed while mothers are feeding away from the colony). Creche size-dependent emigration contributes to the development of ‘multi-divided and small-sized’ nursery colonies, a particular characteristic of R. f. nippon. Such behavior may decrease the maternal costs of the selective nursing.

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In order to observe seasonal movements of sika deer, Cervus nippon, on Mt. Goyo in northern Honshu, the main island of Japan, 18 deer were radio-equipped and their locations were monitored from October 1989 through January 1992. Four deer showed elevational movements (migratory type) and 5 deer stayed in the lower areas (sedentary type), but the movements of 9 other deer were unclear. The migratory type ascended to the higher areas in summer and descended to the foothills in winter, presumably to avoid snow. For a typical migratory deer, the difference between the highest and lowest elevations used was about 620 m, while it was only 230 m for a typical sedentary deer. High density deer populations in the foothills wintering range contained a mixture of the migratory and the sedentary types.

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A rare species of free-tailed bat, Tadarida latouchei, was found on Kuchinoerabu-jima Island of the Osumi group, northern Ryukyu Islands, Japan; the second record of the species from Japan. In addition to the description of the newly collected specimen, we examined relationships among this species and two other closely related species, T. insignis and T. teniotis, on the basis of univariate and multivariate analyses of morphometric characters. External and skull characters, with the exception of tail and tibia lengths, showed no substantial range overlap between T. latouchei and T. insignis or T. teniotis, and these characters in T. latouchei were significantly smaller than those in either T. insignis or T. teniotis, confirming T. latouchei's independence at the specific level. This view is supported further by its relatively short dorsal hairs, thin and roundish ear and large upper anterior premolar.

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A morphological examination of Japanese Eothenomys voles from Nagano City was carried out in order to re-evaluate the identification criteria of the taxa and to compare them with voles from north-eastern, central and western Honshu. The relationship between hind foot length and tail vertebrae length (HFL-TL) divides Japanese Eothenomys voles into two clusters, one of which has been identified as Anderson's red-backed vole E. andersoni and the other as Smith's red-backed vole E. smithii. However, four cranial and dental characteristics (the projection of the lamdoidal crest (LDC), the distance between the tympanic bullae (BTB), and the width and length of the middle lacerate (MLC-w and MLC-l)) contradict the identification based on the HFL-TL relationship. Four specimens from Nagano were clearly identified as E. andersoni on the basis of the HFL-TL relationship, but whereas three of them exhibited andersoni-type cranial and dental characteristics one showed smithii-type characteristics. Thus, cranial characteristics are necessary in order to re-examine the effectiveness of the species identification. It is possible that one of the individuals from Nagano may have resulted from hybridisation between E. andersoni and E. smithii, as has been suggested by previous genetic studies. Hybridisation may result in the ambiguity of the characteristics shown by the atypical individual from Nagano.

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