Although the Chinese government and international organizations have spent millions of dollars estimating the population size of giant pandas (Ailuropoda melanoleuca), the outcomes of such surveys have been debated be...
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Although the Chinese government and international organizations have spent millions of dollars estimating the population size of giant pandas (Ailuropoda melanoleuca), the outcomes of such surveys have been debated because the methods used had uncertain ability to differentiate individuals. Our work in Wanglang Reserve was the first attempt at using fecal microsatellite analysis to enumerate giant pandas (Zhan et al. 2006), and we found the molecular enumeration for the reserve more than doubled that estimated in the third National Survey. Recently, Garshelis et al. (2008) challenged our DNA estimate on the grounds that our study lacked geographic closure and that genotyping errors confounded our results. We challenge both assertions. First, we realize the violation of the assumption of geographic closure is a common problem for noninvasive genetic capture-recapture studies;therefore, we tried in our methodology to minimize geographic closure effects. We conclude that immigration did not greatly affect our main conclusions because of a geographic barrier circling the study area, the limited mobility of giant pandas, and the same sampling intensity was applied to the whole study area. Second, internationally accepted standards were applied to our molecular analysis and appropriate laboratory procedures were taken to produce reliable genotypes. Although we did not report an estimate of genotyping error in our previous work (Zhan et al. 2006), genotyping error rates have now been estimated, but are still pending publication. Based on the Wanglang result, we raised the possibility that there might be more giant pandas in the wild than previously thought. If our prediction is shown to be correct, we do not believe the new estimate will serve to downgrade current endangered status of the giant panda, because population numbers remain very low and panda habitats are fragmented (even more so since the 2008 earthquake). For future conservation of giant pandas, we suggest mor
Only a few primate species thrive in temperate regions characterized by relatively low temperature, low rainfall, low species diversity, high elevation, and especially an extended season of food scarcity during which ...
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Only a few primate species thrive in temperate regions characterized by relatively low temperature, low rainfall, low species diversity, high elevation, and especially an extended season of food scarcity during which they suffer from dietary stress. We present data of a case study of dietary strategies and fallback foods in snub-nosed monkeys (Rhinopithecus bieti) in the Samage Forest, Northwest Yunnan, PRC. The snub-nosed monkeys adjusted intake of plant food items corresponding with changes in the phenology of deciduous trees in the forest and specifically showed a strong preference for young leaves in spring. A non-plant food, lichens (Parmeliaceae), featured prominently in the diet throughout the year (annual representation in the diet was about 67%) and became the dominant food item in winter when palatable plant resources were scarce. Additional highly sought winter foods were frost-resistant fruits and winter buds of deciduous hardwoods. The snub-nosed monkeys' choice of lichens as a staple fallback food is likely because of their spatiotemporal consistency in occurrence, nutritional and energetic properties, and the ease with which they can be harvested. Using lichens is a way to mediate effects of seasonal dearth in palatable plant foods and ultimately a key survival strategy. The snub-nosed monkeys' fallback strategy affects various aspects of their biology, e.g., two- and three-dimensional range use and social organization. The higher abundance of lichens at higher altitudes explains the monkeys' tendency to occupy relatively high altitudes in winter despite the prevailing cold. As to social organization, the wide temporal and spatial availability of lichens strongly reduces the ecological costs of grouping, thus allowing for the formation of "supergroups." Usnea lichens, the snub-nosed monkeys' primary dietary component, are known to be highly susceptible to human-induced environmental changes such as air pollution, and a decline of this critical resourc
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