Abstract
Although pastures are often good feeding sites and can benefit deer population growth, the pasture utilization of sika deer (Cervus nippon yakushimae) in Yakushima Island is not clear. Spotlight counts of deer were conducted in the Nagamine pasture on Yakushima Island every month between 2006 and 2009. Mean deer density utilizing the pasture was estimated to be 420 deer/km2. Deer density in the pasture decreased when spotlight counts were conducted soon after sunset and pasture land was dug up, which may result from higher disturbance by human activity and lower abundance of pasture plants. In contrast to other reports in northern Japan, seasonal variation of pasture utilization by deer was not detected. This may be due to relatively constant quality and quantity of deer forage in the evergreen broad-leaved forests on Yakushima Island. Since 2010, the immediate surroundings Nagamine pasture have changed drastically, and it is therefore important to continue monitoring deer densities in and around the pasture.
