Poster presentation 12th International Mammalogical Congress

What nutrients do wild deer rely on for food selection at natural feeding stations in a warm-temperate forest? (#613)

Naoki Agetsuma 1 , Yoshimi Agetsuma-Yanagihara 2 , Takafumi Hino 3 , Tatsuro Nakaji 3
  1. Field Science Center for Northern Biosphere, Hokkaido University, Kozagawa, Wakayama, Japan
  2. Waku Doki Science Planning, Kozagawa, Wakayama, Japan
  3. Field Science Center for Northern Biosphere, Hokkaido University, Tomakomai, Hokkaido, Japan

Although various studies have investigated food selection by herbivores, there are few observations of wild ungulates actually selecting food items from the range of alternatives available in natural situations. In addition, although many studies of ungulates have examined the effects of key food constituents (e.g. protein, carbohydrate, fiber and secondary metabolites) on food selection, consistent results have not always been obtained. For understanding mechanism of their food selection, further studies are required on feeding behavior of wild ungulates in natural situations. We observed feeding behavior of wild Yaku sika deer (Cervus nippon yakushimae) by following them in a natural forest of Yakushima, Japan, and collected plant samples from 59 feeding stations across seasons. Deer fed on various plant species and parts at the feeding stations, including fallen leaves and fruits of woody plants, and intact woody leaves and herbaceous plants. We analyzed the key constituents of 62 food items and other 171 available plants at the feeding stations. Content of fat, protein and total phenolics showed significant positive effects on food selection by the deer, while lignin and condensed tannin showed significant negative effects. However, soluble carbohydrate and cellulose did not show any significant effects. The higher energy content of fat, compared with sugar or starch, may make it advantageous for the small-sized deer (adult body weight 20-30 kg) that have shorter gastrointestinal tracts to select foods that are relatively rich in fat. The positive effect of total phenolics suggested that non-tannin phenolics may have some beneficial functions.