A mass‐mortality of Sika deer on Kinkazan Island, northern Japan

A Sika deer ( Cervus nippon ) population had been maintained at a level of around 600 head on Kinkazan Island (960 ha), northern Japan during the 1970s and the early 1980s. However, in the spring of 1984 which followed an uncommonly cold winter, a mass‐mortality occurred and about half of the deer population died. A total of 293 recovered carcasses indicated that many had died during a short period (late March and mid‐April). More carcasses were found in the lower altitudinal areas than expected numbers relative to area sizes, suggesting that the deer had moved down from the higher areas to avoid snow. Rumen contents of the carcasses contained much low quality food. Malnutrition caused by the exceptional coldness and late snow was considered to be the factor responsible for mortality.