Hanya Goro, Kiyono Mieko, Hayaishi Shuhei
Primate Research Institute, Kyoto University, Inuyama, Aichi, Japan.
Am J Primatol. 2007 Jul;69(7):802-15. doi: 10.1002/ajp.20397.
We studied the behavioral thermoregulation of Japanese macaques in two troops that live in the coniferous (1,000-1,200 m in elevation) and coastal forests (0-200 m in elevation) of Yakushima. Frequency of sunbathing, huddling, and microhabitat selection during inactivity was compared. The difference in mean annual air temperature between the forests was more than 7 degrees C. In both forests, when the weather was clear, macaques spent more time being inactive in the sunshine in winter than in autumn. In winter, they huddled more often when it was clear than when cloudy. Microhabitat selection to stay in the sunshine during winter differed between the two forests. In winter, macaques spent more time inactive in open habitats in the coniferous forest and in the trees in the coastal forest than in autumn, respectively. This difference is related to the lower crown height in the coastal forest and the large open habitats (logged area) available only in the coniferous forest. In winter, skin temperature measured by temperature-sensitive transmitters was 1.32-1.71 degrees C higher when sunbathing, and 0.83-4.75 degrees C higher when huddling than staying in the shade without huddling. In winter, the proportion with which they stayed in the sunshine or huddled in winter did not differ between the two forests, in spite of the difference in air temperature. This suggests that Japanese macaques respond to seasonal changes in air temperature, not the absolute temperature, and that they acclimatize themselves to thermal conditions that require behavioral thermoregulation only during the season when thermoregulation is most costly.
我们研究了生活在屋久岛针叶林（海拔1000 - 1200米）和沿海森林（海拔0 - 200米）的两群日本猕猴的行为体温调节。比较了不活动期间晒太阳、聚堆以及微生境选择的频率。这两片森林的年平均气温差异超过7摄氏度。在两片森林中，天气晴朗时，猕猴在冬季晒太阳不活动的时间比秋季更多。冬季，天气晴朗时它们聚堆的频率高于多云时。冬季在阳光下停留时的微生境选择在两片森林之间存在差异。冬季，猕猴在针叶林的开阔栖息地以及沿海森林的树上不活动的时间分别比秋季更多。这种差异与沿海森林较低的树冠高度以及仅在针叶林存在的大片开阔栖息地（砍伐区域）有关。冬季，通过温度敏感发射器测量，晒太阳时皮肤温度比不聚堆待在阴凉处高1.32 - 1.71摄氏度，聚堆时高0.83 - 4.75摄氏度。尽管气温存在差异，但冬季两群猕猴在阳光下停留或聚堆的比例并无不同。这表明日本猕猴对气温的季节性变化而非绝对温度做出反应，并且它们仅在体温调节成本最高的季节适应需要行为体温调节的热条件。
