Mammal Study

Using two populations of sika deer Cervus nippon, the relationship between tick density within habitats and the duration of both self-grooming and allogrooming was investigated. At Mageshima Island, where the deer spend much of their time feeding and tick density is high, the time spent self-oral grooming frequency fluctuated with tick density within the deer's habitat. However, in Nara Park, where the deer are fed artificially and tick density is low, neither oral nor self-scratch grooming correlate with tick density. Although tick density is much higher at Mageshima than at Nara Park, the overall duration of self-grooming did not differ between these sites, suggesting that this was affected by the time budget required for other behaviors, especially foraging. Allogrooming duration did not correlate with tick density at either study sites, suggesting that the most important function of this behavior is a social one, rather than the removal of ectoparasites.

Food habits of sika deer Cervus nippon show great variations at a macro-scale geographical range and some variations even at micro-scale of locations such as islands or mountains, but there is no study at meso-scale. We investigated variation in the food habits of sika deer over a meso-scale range encompassing high mountains and hilly areas in Tochigi Prefecture, central Japan. Rumen contents sampled from deer culled in the winter of 1996 (n = 147) in 10 localities were analyzed using the point-frame method. Local variation in food composition was high. Detrended correspondence analysis (DCA) showed that food composition varied from the western high mountain region, where low quality foods (dead leaves, bark, and culms) were dominant, to northern and eastern areas, where a dwarf bamboo Sasa nipponica, which grew in the understory of oak forests, was dominant. Two intermediate localities between the western and eastern areas and another eastern locality fell between the western high area and the eastern low area in the ordination. The proportion of S. nipponica varied from 0% to 99% among all samples, and from 0.5% to 60% among the 10 localities. S. nipponica occupied >50% of rumen contents in 52 samples (35.4%). Thus, the food habits of sika deer varied greatly, even within a meso-scale range of 2000 km², depending on food availability in the different habitats.

Samples of the sika deer (Cervus nippon) were collected from Kyushu and Shikoku Islands of Japan and surrounding areas, and their nucleotide sequences were analyzed. Sequences of the whole control region of the mitochondrial DNA were determined and phylogenetic trees were constructed using the neighbor-joining method and the maximum likelihood method. We also investigated gene genealogies for the sequences using the statistical parsimony network approach. Phylogenetic trees showed that only the Yakushima/Tanegashima populations were genetically distant from other populations. The statistical parsimony network, however, indicated a close relationship of the Miyazaki populations to some of the Shikoku populations. It was suggested that Shikoku Island played an important role in the divergence from the southern Japan lineage of C. nippon.