Altitudinal and seasonal variations in the diet of Japanese macaques in Yakushima.
Altitudinal and seasonal variations in the diet of Japanese macaques in Yakushima, southwestern Japan, were studied for 2 years by means of fecal analysis. The altitudinal range of fecal samples collected was 30 m to 1,203 m above sea level, and it was divided into three zones: low-zone forest (0-399 m), middle-zone forest (400-799 m), and high-zone forest (800 m-1,230 m). There was a considerable altitudinal and seasonal variation in the macaques' diet. Seed/fruit and animal matter were eaten more in the lower zones, whereas more fiber and fungi were consumed in the higher zones. In all of the zones, they ate seed/fruits the most in autumn (September-November) and the least in spring (March-April). They ate fibrous food the most in spring and the least in autumn. Macaques relied on seed/fruits heavily in the lower zone for a longer period than in the higher zones. Macaques in the high-zone forest ate almost no seed/fruit foods from March to May. Altitudinal variations in availability of seed/fruit foods seem to have influenced the altitudinal variations in diet. Total basal area of seed/fruit-food trees, species richness of seed/fruit-foods, main seed/fruit-food types available, and annual fleshy-fruit production all decreased with increasing altitude. Both interannual variation and annual cyclicity of diet were found in all zones.
Hanya
Goro
G
Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Japan. hanya@jinrui.zool.kyoto-u.ac.jp
Noma
Naohiko
N
Agetsuma
Naoki
N
D000531:Altitude; D000818:Animals; D004032:Diet; D005243:Feces / Q000737:chemistry; D005638:Fruit; D005658:Fungi; D007564:Japan; D008251:Macaca / Q000502:physiology*; D012621:Seasons; D012639:Seeds; D014197:Trees