Understanding the Role of Ecology in Saving the Orangutan from Extinction

在野外，猩猩正面临灭绝的危险，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，种群内部和种群之间都存在显著的生殖变异。居住在婆罗洲岛（Pongo pygmaeus）和苏门答腊岛（P. abelii）的猩猩之间的遗传差异可能解释了它们的多样性，但生态变异也可能起着重要作用。为了解决这个问题，来自婆罗洲和苏门答腊岛四个实地地点的研究人员将合作，对猩猩的生态学、能量学、生活史和激素生理学进行深入研究。一个主要目标是了解饮食的变化以及由此导致的体重增加或减少如何影响生殖功能。这将通过测量尿液中的激素来评估，并使记录生殖状态的变化成为可能，例如当一个人在分娩后开始骑车。这些生殖变化将与粮食供应和能量状况的变化联系在一起。尿液样本将用于验证非侵入性身体状况评估的创新技术，然后可以应用于其他物种。该项目的结果将对理解动物的生活史特征（如首次繁殖的年龄和生育间隔的长度）的进化具有潜在的重要影响。生活在稳定、低死亡率环境中的物种，生活史变异模型预测的是较慢、较长的生活史，生育间隔较长。一个来自生殖生态学领域的对比模型表明，在类人猿（包括人类）占据更高质量栖息地的种群中，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，前者生活在食物更多的环境中，而婆罗洲猩猩的食物波动更大。研究这两个物种之间的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。该研究的重点是跨现场合作，以最大限度地利用数据，并允许使用相同的方法在研究区域内复制研究结果，同时改善每个站点的基础设施和设施；这个过程将促进和提供机会训练学生的行为观察和实验室技术。猩猩在遗传和生理上与人类有很多相似之处，但其生育间隔却是人类的两到三倍，因此对猩猩繁殖的研究对理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，研究濒危物种的繁殖在量化生境退化对繁殖率的影响方面具有重要的保护应用价值。通过为保护管理提供必要的知识，阻止非法采伐，并通过参与周围社区的保护工作，该项目将使人们更多地关注仅存的猩猩种群，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策略之一。

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.