Effects of density, season, and food intake on sika deer nutrition on Yakushima Island, Japan

Sika deer on Yakushima Island, Japan, maintain good nutritional status even in high-density areas and during winter, contrary to observations in northern Japan. The study found no significant correlation between deer density or season and the Riney's kidney fat index (RKFI), a measure of nutritional condition, with average RKFI values exceeding 20 across all five study sites. Food intake positively influenced RKFI, except near a town ranch where an L-shaped distribution was observed. The research analyzed RKFI and stomach contents from 74 culled deer across varying densities, revealing that food selectivity, rather than body weight or age, drove individual differences in intake.

Kuroiwa, A., Kuroe, M., & Yahara, T. (2017). Effects of density, season, and food intake on sika deer nutrition on Yakushima Island, Japan. Ecological Research, 32(3), 369–378. Portico. https://doi.org/10.1007/s11284-017-1443-6