To clarify the reason(s) why sika deer, Cervus nippon, on Mt. Ohdaigahara strip bark, we examined two hypotheses: (1) bark improves rumen digestion in summer; and (2) deer eat bark to obtain minerals in summer to remedy mineral imbalances. Rumen fluid and blood plasma of sika deer on Mt. Ohdaigahara were collected from culled deer for in vitro experiments and blood plasma analyses. The in vitro digestibilities of Sasa nipponica leaves (the primary forage of sika deer on Mt. Ohdaigahara), Abies homolepis bark, and a 20 : 1 mixture of S. nipponica leaves and A. homolepis bark were examined to clarify the effects of bark presence on digestion of S. nipponica leaves. The in vitro digestibilities of S. nipponica leaves did not change with season. The in vitro digestibilities of S. nipponica leaves in the mixture were not significantly different from those of S. nipponica leaves. The in vitro digestibilities of bark changed seasonally, and were negative in spring. This phenomenon might be caused by the different chemical and microbiological conditions of rumen fluid. Deer blood plasma profiles were analyzed to clarify their mineral levels. The K content in summer was significantly higher than in other seasons, probably be cause the K content of S. nipponica leaves peaks in summer. The blood plasma profiles of other minerals were normal, suggesting that hypothesis (2) is incorrect.

We estimated phylogenetic relationships among shrews of the Sorex caecutiens/shinto group (Eulipotyphla, Soricidae) from various locations through its range, based on restriction fragment length polymorphism (RFLP) analysis of the nuclear ribosomal RNA gene (rDNA) spacer region. Seven rDNA-RFLP repetitive types (repetypes) were recognized among 15 shrews examined. Restriction patterns of Sorex caecutiens Laxmann, 1788 and S. shinto Thomas, 1905 were distinguishable from each other, but the separation was not statistically supported in the maximum parsimony analysis. The RFLP repetype from Cheju Island was close to that of S. caecutiens from the Eurasian continent, indicating that the shrew of Cheju should be classified as S. caecutiens. Within S. caecutiens, there were two alternative phylogenetic hypotheses. According to a parsimonious tree and a simple network, the Hokkaido population was regarded to be derived from the Sakhalin population, which in turn was derived from the continental population. Alternatively, it was inferred that the continent and Hokkaido populations were firstly separated from the ancestral population, and then shrews from both populations immigrated into Sakhalin and hybridization occurred there. The latter hypothesis seems to be more plausible because it is more congruent with a previous mitochondrial phylogeny.

We report the first karyological description of a southeast Asian mole, the Malaysian mole (Euroscaptor micrura malayana). The karyotype of the Malaysian mole includes 36 chromosomes, which consist of 18 biarmed and 16 acrocentric autosomes and the sex pair. The sex chromosomes are a small meta-submetacentric X chromosome and a minute dot-like Y chromosome, although the latter is somewhat larger than that of some talpid allies. Autosomal complements include one pair of NOR-bearing chromosomes. A comparative G-banding analysis with the Japanese congener E. mizura showed that these two species share high G-banding homology, and their differences on two pairs of chromosomes are explained by a single reciprocal translocation. The karyological similarity of these distant geographic species is discussed in a systematic and evolutionary context, based on comparisons to other species distributed between them.

The taxonomic status of a shrew species, Soriculus baileyi Thomas, 1914 (Insectivora, Soricidae) was re-evaluated on the basis of external and cranial morphological characteristics. Soriculus baileyi is considered a valid species of the subgenus Episoriculus. It is a large species with a tail shorter than or as long as the head and body length, and is distinguished from the other Episoriculus species, S. leucops, S. caudatus, S. fumidus, and S. macrurus, in having the combination of robust first upper incisor, long rostrum and upper unicuspid row, large tympanic ring, and high ascending ramus of mandible. Soriculus baileyi is known from Sikkim and Assam in India, Myanmar, and Vietnam. Morphometric variation among Episoriculus species is discussed based on principal component analysis.

The heart structure of the Asian elephant (Elephas maximus) was observed by macroscopic and CT scanning methods. The heart was 8,230 and 9,640 g in weight, 480 and 550 mm in length in the two examined elephants, respectively. In the right ventricle, the papillary muscles in the interventricular septum were identified as M. papillaris subarteriosus et parvus, whereas in the ventricular wall as M. papillaris magnus. The Chordae tendineae from the M. papillaris subarteriosus et parvus reached the margin of the Cuspis angularis, whereas the Chordae tendineae from the M. papillaris magnus supported the Cuspis septalis of the right atrioventricular valve. In the Cuspis parietalis area, the Chordae tendineae connected this valve with the M. papillaris magnus. The left atrioventricular (bicuspid) valve consisted of Cuspis septalis and the Cuspis parietalis, that the Chordae tendineae reached from M. papillaris subauricularis et subatrialis. From the CT sections, we demonstrated that the left ventricular wall was 50–60 mm in left lateral side of the ventricular wall, whereas the right ventricular wall appeared 15–25 mm in thickness. The atria possessed the wall of 15–30 mm in thickness. In the Asian elephant the heart certainly requires a large volume and a thick ventricular wall, however, the muscular wall is not equipped with the highly-functioned structure adapted to its large body size.

Habitat fragmentation affects population density, resulting in a higher probability of extinction and lower rates of recolonization of habitat patches in some holarctic tree squirrels. Several local populations of the Japanese squirrel, Sciurus lis, seem to have decreased during the 1990s. We tested the hypothesis that the contracting distribution of Japanese squirrels is connected with habitat fragmentation via forest destruction for human land use. We investigated whether woodlot characteristics and degrees of woodlot isolation affected the presence of squirrels in suburban fragmented woodlots in western Tokyo. Japanese squirrels were present in 12 of 76 woodlots. Squirrel presence was not detected in all 23 woodlots east of a single north-south trending road within the study area. This result suggested that the road prevented squirrels from dispersing from the mountainous range west of the study area into eastern woodlots. In 53 woodlots west of the road, woodlot size and preferred habitat had positive effects on the probability of squirrel presence, whereas isolation variables did not affect its presence. We suspected that the habitat fragmentation via forest destruction for human land use might be one of the causes leading to the recent diminishing in local populations of Japanese squirrels.

We used the mark-recapture method to gather fundamental information on population dynamics of the Japanese water shrew (Chimarrogale platycephala) in a mountain stream from April through December 2004. Trapping was conducted over 2,700 nights, during which 58 captures of 24 individuals occurred. The numbers of individuals were higher in the upper stream reach where few modifications were made, and lower downstream where dams of several meters in height and concrete-lined wall were located. Of 23 individuals (excepting one drowned individual), eight were not recaptured, six were recaptured within one month, and nine were recaptured within two to seven months after initial capture. These results suggest that the population size of the Japanese water shrew has been negatively affected by river modifications, and there are specific tendencies in their movement pattern.