冬季来临时,一些恒温动物从高纬度地区迁徙到低纬度地区,一些从高海拔地带垂直迁徙到低海拔地带,还有一些选择了冬眠等。然而,世界上分布区海拔最高的非人灵长类动物——黑白仰鼻猴(滇金丝猴),却选择在多年家域的中高海拔段地带越冬。
针对黑白仰鼻猴的这一“反常”行为,中科院昆明动物研究所生态学与环境保护中心GIS小组与中科院西双版纳热带植物园热带森林生态学重点实验室动植物关系研究组等进行了合作研究,通过对藏东南小昌都黑白仰鼻猴群的跟踪调查,结合GIS分析,取得以下主要研究结果:1)虽然此猴群的多年家域范围在海拔3500-4500米之间,但其冬季利用的主要区域在较高的海拔4100-4400米之间;2)研究地点的气温虽然随着海拔高度的增加而降低,但太阳辐射强度和日照时长却随着海拔高度的增加而增加;3)黑白仰鼻猴冬季栖息地利用与太阳辐射强度和日照时长呈显着相关;4)黑白仰鼻猴在下雪后通常移动到太阳辐射较强和日照时间较长的高海拔地带,这里通常积雪融化快,其主要食物地衣也暴露的较早。研究结果证实了太阳辐射是影响黑白仰鼻猴小昌都猴群冬季家域选择的重要的因素之一,提出了解释黑白仰鼻猴冬季偏好在高海拔地带越冬的“光照假说”,这与此前人们用来解释野生动物季节性迁移模式的食物丰富度、温度、捕食者等假说有所不同。(生物谷Bioon.com)
doi:10.1371/journal.pone.0024449
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Why Does Rhinopithecus bieti Prefer the Highest Elevation Range in Winter? A Test of the Sunshine Hypothesis
Rui-Chang Quan1#, Guopeng Ren2#, Jocelyn E. Behm3, Lin Wang2, Yong Huang2, Yongcheng Long4, Jianguo Zhu2*
Environmental factors that affect spatiotemporal distribution patterns of animals usually include resource availability, temperature, and the risk of predation. However, they do not explain the counterintuitive preference of high elevation range in winter by the black-and-white snub-nosed monkey (Rhinopithecus bieti). We asked whether variation of sunshine along with elevations is the key driving force. To test this hypothesis, we conducted field surveys to demonstrate that there was a statistically significant pattern of high elevation use during winter. We then asked whether this pattern can be explained by certain environmental factors, namely temperature, sunshine duration and solar radiation. Finally, we concluded with a possible ecological mechanism for this pattern. In this study, we employed GIS technology to quantify solar radiation and sunshine duration across the monkey's range. Our results showed that: 1) R. bieti used the high altitude range between 4100–4400 m in winter although the yearly home range spanned from 3500–4500 m; 2) both solar radiation and sunshine duration increased with elevation while temperature decreased with elevation; 3) within the winter range, the use of range was significantly correlated with solar radiation and sunshine duration; 4) monkeys moved to the areas with high solar radiation and duration following a snowfall, where the snow melts faster and food is exposed earlier. We concluded that sunshine was the main factor that influences selection of high elevation habitat for R. bieti in winter. Since some other endotherms in the area exhibit similar winter distributional patterns, we developed a sunshine hypothesis to explain this phenomenon. In addition, our work also represented a new method of integrating GIS models into traditional field ecology research to study spatiotemporal distribution pattern of wildlife. We suggest that further theoretical and empirical studies are necessary for better understanding of sunshine influence on wildlife range use.