Why do sika deer, Cervus nippon, debark trees in summer on Mt. Ohdaigahara, central Japan?

抄録

Bark stripping by sika deer, Cervus nippon, causes severe damage to forests. The seasonality of bark stripping by deer and tree selection were examined on Mt. Ohdaigahara in central Japan. The chemical content and physical properties of the bark were analyzed. About 60% of all tree species suffer various degrees of seasonal bark stripping. Bark stripping is most intensive during summer when the deer's main forage, Sasa nipponica, is abundant, suggesting that bark stripping is not due to food shortages. The bark physical properties seem to affect barking selection among three coniferous species, but not its seasonality. The nutritive value of bark is lower than that of S. nipponica, which has high crude protein and hemicellulose contents in summer but an inadequate mineral balance in summer, suggesting that sika deer eat the bark either to balance the digestible nutrients of summer forage and/or to attain a proper mineral balance in summer.