Understanding the Role of Ecology in Saving the Orangutan from Extinction

红毛猩猩在野外面临灭绝的危险，但科学家们才刚刚开始了解影响它们繁殖的变量。 现有的证据表明，人口内和人口之间的生殖差异显着。 居住在婆罗洲岛（Pongo pygmaeus）和苏门答腊岛（P. abelii）的红毛猩猩之间的遗传差异可以解释大部分的多样性，但生态变化也可能发挥重要作用。 为了解决这个问题，来自婆罗洲和苏门答腊岛四个实地考察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变化以及由此产生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，并有可能记录生殖状态的变化，例如分娩后个体何时开始骑自行车。 这些生殖变化将与食物供应和能量状态的变化有关。 尿液样本将用于验证非侵入性身体状况评估的创新技术，然后将其应用于其他物种。 该项目的结果将对理解动物生活史特征（如首次繁殖的年龄和生育间隔的长度）的演变产生潜在的重要影响。 生活史变异模型预测生活在稳定、低死亡率环境中的物种的生活史更慢、更长，生育间隔更长。 一个对比模型，从生殖生态学领域，表明更高的繁殖率，更快的生活史变量，发现在种群的大型类人猿物种（包括人类）占据更高质量的栖息地。 因此，这两个模型对苏门答腊猩猩的比较做出了不同的预测，苏门答腊猩猩生活在食物供应更多的环境中，而婆罗洲猩猩的食物波动更大。 调查这两个物种之间的生活史进化与共享的生理反应的相对重要性将作为其他物种的比较研究的模型。这项研究的重点是各实地地点之间的合作，以最大限度地利用数据，并利用相同的方法在各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备;这一进程将促进并提供机会，对学生进行行为观察和实验室技术方面的培训。 红毛猩猩与人类有着大量的遗传和生理相似之处，但生育间隔是人类的两到三倍，因此研究红毛猩猩的繁殖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，濒危物种的繁殖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，阻止非法砍伐，并通过参与周围社区的保护工作，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.