Dissertation Research: The Ecological Influences on Activity Cycle in Two Cathemeral Lemurid Primates, Eulemur mongoz and Eulemur fulvus fulvus

绝大多数灵长类动物，包括人类，在解剖学和行为学上都适应于夜行（夜间活动）或昼行（白天活动）的生活方式。然而，马达加斯加的一群原猿灵长类动物表现出明显不同的活动周期，在白天或晚上的任何时候都有可能活动。尽管这种24小时的活动在其他哺乳动物中很常见，但在灵长类动物中却极为罕见。因此，在本论文的研究中，将收集15个月的数据来研究两种狐猴物种，猫鼬狐猴（Eulemur mongoz）和普通棕色狐猴（Eulemur fulvus fulvus）的24小时活动。这项研究将在马达加斯加西北部Ankarafantsika自然保护区的热带干燥森林进行。具体来说，这项研究将试图确定这些灵长类动物的24小时活动是否受到诸如食物供应、捕食者压力和气候等自然环境特征的驱动。此外，这项研究将检查狐猴白天和夜间的行为是否存在差异。这项研究的结果将用于生成一个模型来解释为什么24小时的活动周期对这些灵长类动物是适应性的，并更好地理解活动周期在人类和非人类灵长类动物进化史中的重要性。

The vast majority of primates, including humans, possesses anatomical and behavioral adaptations for either a nocturnal (night-active) or diurnal (day-active) lifestyle. A group of prosimian primates in Madagascar, however, displays a distinctly different activity cycle where there is a potential for activity at any time of the day or night. Although such 24-hour activity is common among other mammalian species, it is extremely unusual in primates. Therefore, in this proposed dissertation study, fifteen months of data will be collected to examine the 24-hour activity in two lemur species, the mongoose lemur (Eulemur mongoz) and the common brown lemur (Eulemur fulvus fulvus). The research will be conducted in the tropical dry forest of Ankarafantsika Nature Reserve in northwest Madagascar. Specifically, this study will attempt to determine whether 24-hour activity in these primates is driven by such features of their natural environment as food availability, predator pressure, and climate. In addition, this study will examine whether any differences exist between the lemurs' daytime and nighttime behavior. The results of this research will be used to generate a model explaining why a 24-hour activity cycle is adaptive for these primates, and to also reach a better understanding of the importance of activity cycle in the evolutionary history of human and non-human primates.