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

摘要

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.