Why Do Sika Deer Head for the Alpine Zone in Japan?

Abstract

We captured sika deer in the Northern and Southern Japanese Alps and monitored their seasonal movement patterns in the surrounding area. The daily air temperature in early June reached 5°C and the plants’ growing period persisted for four months. Alpine sika deer are thought to stay in the alpine zone from the plants’ early growing period. The alpine sika deer observed stayed in the alpine zone to feed on alpine vegetation and Betula forest understory. The autumn migration of these alpine sika deer started in September. These adult sika deer repeated the same seasonal migration pattern each year. One sika deer exhibited a long-distance dispersal movement, with a straight-line distance and actual distance between its natal range and post-dispersal range of 74 km and 131 km, respectively. This evidence of long-distance dispersal of sika deer may explain the expanding distribution of sika deer in central Honshu.