Partial migration and effects of climate on migratory movements of sika deer in Kirigamine Highland, central Japan

Studies on migration pattern of sika deer in Japan are limited. We captured 27 sika deer and identified movement for 24 deer (17 females and 7 males) from 2008 to 2011 in Kirigamine Highland, Nagano, central Japan. Four juvenile males dispersed from their original home range, and we documented migration pattern for 23 deer (17 females and 6 males), including 3 dispersed males. Deer exhibited partial migration, regardless of sex: 65% (n = 15) of the deer were migratory, whereas 35% (n = 8) were non-migratory. All but 1 of the migratory deer migrated between high-elevation summer range and low-elevation winter range. Mean migration distance was 9.9 km (range = 3.2-22.9 km). Fidelity to summer home range was stronger than fidelity to winter home range. In order to determine the effect of climate on the onset of migration at Kigiramine Highland, we examined 39 seasonal movements during 4 migratory periods. Most of autumn migrations occurred before the snow depth reached 20 cm. Spring migrations occurred after the daily temperatures > 0 degrees C persisted for more than 3 days, and during periods when either snow had completely disappeared or snow melted rapidly.ArticleMAMMAL STUDY. 37(4):331-340 (2012)journal articl

An initial record of a long-distance dispersal route of a male sika deer in central Japan

Mammalia. 84(1), 63-68 (2019)journal articl

Seasonal migration of sika deer in the Oku-Chichibu Mountains, central Japan

Movements and seasonal home ranges of 6 GPS collared sika deer were investigated at the Oku-Chichibu Mountains, central Honshu, from April 2009 to March 2010. All deer migrated between discrete summer and winter home ranges. The linear migration distance ranged from 2.5 to 31.9 km. Mean elevation during the summer and the winter ranged from 980 to 1,782 m, and from 1,204 to 1,723 m, respectively. Two deer were upward migrants and 4 deer were downward migrants. Taking into consideration of the relatively small snow accumulation in the summer home range, the possibility of autumn migration to avoid deep snow is low. The percentage of steep slope in the winter home range was higher than that in the summer. Bamboo grass was not found in the summer home range, but was predominant in the winter home range. Road density decreased in the winter home range compared to the summer. Only 2 out of 6 deer stayed mainly in the wildlife protection area during the winter. Our results indicate that the autumn migration was affected by winter forage and human disturbance, thereby assured the survival of the deer during winter.ArticleMAMMAL STUDY. 37(2):127-137 (2012)journal articl

Seasonal Migration of Sika Deer in the Oku-Chichibu Mountains, Central Japan

Movements and seasonal home ranges of 6 GPS collared sika deer were investigated at the Oku-Chichibu Mountains, central Honshu, from April 2009 to March 2010. All deer migrated between discrete summer and winter home ranges. The linear migration distance ranged from 2.5 to 31.9 km. Mean elevation during the summer and the winter ranged from 980 to 1,782 m, and from 1,204 to 1,723 m, respectively. Two deer were upward migrants and 4 deer were downward migrants. Taking into consideration of the relatively small snow accumulation in the summer home range, the possibility of autumn migration to avoid deep snow is low. The percentage of steep slope in the winter home range was higher than that in the summer. Bamboo grass was not found in the summer home range, but was predominant in the winter home range. Road density decreased in the winter home range compared to the summer. Only 2 out of 6 deer stayed mainly in the wildlife protection area during the winter. Our results indicate that the autumn migration was affected by winter forage and human disturbance, thereby assured the survival of the deer during winter.ArticleMAMMAL STUDY. 37(2):127-137 (2012)journal articl

Dietary specialization depending on ecological context and sexual differences in Asiatic black bears.

The food habits of the Asiatic black bear (Ursus thibetanus) are well studied, but there is a little evidence of dietary specialization-that is, when individuals use a narrower set of resources compared to the population as a whole. To examine the dietary composition at the individual level, seasonal patterns of dietary specialization, and sex-based dietary differences in Asiatic black bears, we attached Global Positioning System (GPS) collars to 15 Asiatic black bears and collected their scats in Nagano Prefecture, Japan from 2017 to 2018. Our results showed that the dietary composition differed among individuals, although seasonal changes in dietary composition were observed at the population level. Dietary specialization was high in summer (resources less abundant) and low in spring and autumn (resources more abundant), indicating a relationship with general food abundance and the dietary diversity of bears. In spring, all bears consumed green vegetation and/or seed of Fagaceae family from previous autumn; in early- and late- summer, dietary composition, such as green vegetation, insects, and fruits, greatly differed among individuals. In autumn, most bears heavily depended on seeds of Fagaceae which is high-quality food for bears. Although we did not find statistical differences between sexes in terms of dietary specialization and diversity, we found variations in the timing of feeding on the Fagaceae family, being earlier in females compared with males. We also found considerable variation in dietary composition within sexes, suggesting that dietary specialization depends on multiple factors besides food abundance, food diversity, and sex

Habitat Selection of a Large Carnivore along Human-Wildlife Boundaries in a Highly Modified Landscape

<div><p>When large carnivores occupy peripheral human lands conflict with humans becomes inevitable, and the reduction of human-carnivore interactions must be the first consideration for those concerned with conflict mitigation. Studies designed to identify areas of high human-bear interaction are crucial for prioritizing management actions. Due to a surge in conflicts, against a background of social intolerance to wildlife and the prevalent use of lethal control throughout Japan, Asiatic black bears (<i>Ursus thibetanus</i>) are now threatened by high rates of mortality. There is an urgent need to reduce the frequency of human-bear encounters if bear populations are to be conserved. To this end, we estimated the habitats that relate to human-bear interactions by sex and season using resource selection functions (RSF). Significant seasonal differences in selection for and avoidance of areas by bears were estimated by distance-effect models with interaction terms of land cover and sex. Human-bear boundaries were delineated on the basis of defined bear-habitat edges in order to identify areas that are in most need of proactive management strategies. Asiatic black bears selected habitats in close proximity to forest edges, forest roads, rivers, and red pine and riparian forests during the peak conflict season and this was correctly predicted in our human-bear boundary maps. Our findings demonstrated that bears selected abandoned forests and agricultural lands, indicating that it should be possible to reduce animal use near human lands by restoring season-specific habitat in relatively remote areas. Habitat-based conflict mitigation may therefore provide a practical means of creating adequate separation between humans and these large carnivores.</p></div

Distribution of the boundaries between humans and Asiatic black bears in the central Japan Alps (10×10 m resolution).

<p>The colors indicate sharp boundary: the overlapped edges of RSF class 9–10 and human lands (red) and moderate boundary: the overlapped edges of RSF class 7–8 and human lands (orange). The different panels show HB boundaries for females in summer (top left), females in autumn (top right), males in summer (bottom left) and males in autumn (bottom right).</p

Landscape covariates considered to influence habitat selection by Asiatic black bears in the central Japan Alps. 9 land cover types were reclassified (6 types of vegetation, 2 human-landscape classes and others) from a satellite image with 10 m resolution.

<p>Landscape covariates considered to influence habitat selection by Asiatic black bears in the central Japan Alps. 9 land cover types were reclassified (6 types of vegetation, 2 human-landscape classes and others) from a satellite image with 10 m resolution.</p