Understanding the Role of Ecology in Saving the Orangutan from Extinction

猩猩在野外面临灭绝的危险，然而科学家们才刚刚开始了解影响它们繁殖的变量。现有证据表明，种群内和种群间的生殖差异都很大。居住在婆罗洲(Pongo Pigmaeus)和苏门答腊岛(P.abelii)的猩猩之间的遗传差异可能解释了很大程度上的多样性，但生态变异也可能起到重要作用。为了解决这个问题，来自婆罗洲和苏门答腊岛四个野外地点的研究人员将合作对猩猩的生态学、能量学、生活史和荷尔蒙生理学进行深入研究。一个主要的目标是了解饮食的变化以及由此导致的体重增加或减轻如何影响生殖功能。这将通过测量尿液中的激素进行评估，并可能记录生殖状态的变化，例如个体在分娩后开始循环的时间。这些生殖变化将与食物供应和能源状况的变化联系在一起。尿样将被用来验证创新的非侵入性身体状况评估技术，然后可以应用于其他物种。该项目的结果将对理解动物生活史特征的进化(如第一次繁殖的年龄和出生间隔的长度)产生潜在的重要影响。生活史变异模型预测，在生活在稳定、低死亡率环境中的物种中，生命历史更慢、更长，两次出生的间隔更长。生殖生态学领域的一个对比模型表明，在栖息地质量较高的类人猿物种(包括人类)中，发现更高的繁殖率和更快的生活史变量。因此，这两个模型对苏门答腊猩猩和婆罗洲猩猩的比较做出了不同的预测。苏门答腊猩猩生活在食物更易获得的环境中，而婆罗洲猩猩的食物波动更大。研究这两个物种生活史进化与共同生理反应的相对重要性，将为其他物种的比较研究提供一个模型。这项研究的重点是跨外地地点的协作，以最大限度地利用数据，并允许利用相同的方法在研究领域复制研究结果，同时改善每个地点的基础设施和设施；这一进程将促进和提供培训学生行为观察和实验室技术的机会。猩猩在遗传和生理上与人类有很大的相似性，但出生间隔是人类的两到三倍，因此研究猩猩的繁殖对于了解人类生活史的进化和生殖适应具有重要的应用价值。最后，濒危物种繁殖的研究在量化栖息地退化对繁殖率的影响方面具有重要的保护应用。通过提供保护管理所必需的知识，阻止非法采伐，并通过参与周边社区的保护工作，该项目将使人们更加关注最后剩下的猩猩种群，科学和保护目标的协同作用可能是拯救这些物种及其栖息地的最佳战略之一。

Orangutans are at risk of becoming extinct in the wild, yet scientists are only beginning to understand the variables that influence their reproduction. Existing evidence suggests significant reproductive variation both within and between populations. Genetic distinctions between orangutans inhabiting the islands of Borneo (Pongo pygmaeus) and Sumatra (P. abelii) may explain much of the diversity, yet ecological variation may also play a significant role. To address this, researchers from four field sites on Borneo and Sumatra will collaborate on an intensive study of ecology, energetics, life history, and hormonal physiology in orangutans. One major objective is to understand how variation in diet and resulting weight gain or weight loss influences reproductive functioning. This will be evaluated through measurement of hormones in urine and make possible the documentation of changes in reproductive status, such as when an individual begins cycling after giving birth. These reproductive changes will be linked to changes in food availability and energy status. Urine samples will be used to validate innovative new techniques for the non-invasive assessment of physical condition which can then be applied to other species. The results of this project will have a potentially important impact on understanding the evolution of life history traits (such as the age at first reproduction and the length of the interval between births) in animals. Models of life history variation predict slower, longer life histories, with longer intervals between births, in species living in stable, low mortality environments. A contrasting model, from the field of reproductive ecology, indicates that higher reproductive rates, and faster life history variables, are found within populations of great ape species (including humans) occupying higher quality habitat. Thus, these two models make different predictions for the comparison of Sumatran orangutans, who live in an environment of more food availability, compared to Bornean orangutans, where food fluctuates more. Investigating the relative importance of life history evolution versus shared physiological responses between these two species will serve as a model for comparative studies of other species. The study focuses on collaboration across field sites to maximize data and to allow for replication of findings across study areas utilizing identical methodologies while improving the infrastructure and facilities at each site; this process will facilitate and provide opportunities for the training of students in behavioral observation and laboratory techniques. Orangutans share substantial genetic and physiological similarities with humans, yet have inter-birth intervals two to three times as long, thus the study of orangutan reproduction has important applications to understanding the evolution of human life history and reproductive adaptation. Finally, the study of reproduction in endangered species has important conservation applications in quantifying the influence of habitat degradation on reproductive rates. By providing knowledge essential for conservation management, deterring illegal logging and through involvement in conservation efforts in surrounding communities, this project will bring increased attention to the last remaining populations of orangutans, and the synergy of scientific and conservation goals may be one of the best strategies at hand for saving these species and their habitats.