Tinsman Jen, Volampeno Sylviane, Ganas-Swaray Jessica, Gann Daniel, Andrianirina Natacha, Chamizo Madison, Ralazampirenena Claude, Ranaivoarisoa Jean F, Ravaoarisoa Hasina, Rivero Josie, Zamora Andrew, Gomes Cristina M
Tropical Conservation Institute, Institute of Environment, Florida International University, Miami, Florida, USA.
Center for Tropical Research, Institute of the Environment & Sustainability, University of California, Los Angeles, USA.
Am J Primatol. 2022 Mar;84(3):e23362. doi: 10.1002/ajp.23362. Epub 2022 Jan 31.
Madagascar's lemurs are threatened by forest loss, fragmentation, and degradation. Many species use flexible behaviors to survive in degraded habitat, but their ability to persist in very small areas may be limited. Insular lemurs, like those found on Nosy Be, an island off the northwestern coast of Madagascar, are at heightened risk of sudden population declines and extirpation. Nosy Be is home to two Critically Endangered species-the endemic Nosy Be sportive lemur (Lepilemur tymerlachsoni) and Claire's mouse lemur (Microcebus mamiratra)-as well as the Endangered black lemur (Eulemur macaco). Most of the remaining forest on Nosy Be is protected by the 862-ha Lokobe National Park. To document how Nosy Be lemurs use their restricted habitat, we conducted vegetation and reconnaissance surveys on 53 transects in and around Lokobe. We collected data on tree size, canopy cover, understory visibility, and elevation for 248 lemur sightings. We used a spatially explicit, multi-species occupancy model to investigate which forest-structure variables are important to lemurs. Our results represent some of the first data on habitat use by insular lemurs. Black lemurs preferred significantly larger trees and areas with less dense understory. They also occurred significantly less outside of Lokobe National Park, even when accounting for sampling effort and geography. The distributions of the sportive and mouse lemurs were not related to the forest structure variables we documented, but they did negatively predict each other-perhaps because their habitat requirements differ. These results also underscore the importance of the national park to protecting the black lemur population on Nosy Be and raise questions about what factors do influence the distribution of Nosy Be's smaller lemurs. Close monitoring is needed to prevent these populations and the ecosystem services they provide from disappearing, as have other island lemurs.
马达加斯加的狐猴受到森林丧失、碎片化和退化的威胁。许多物种利用灵活的行为在退化的栖息地中生存，但它们在非常小的区域内持续生存的能力可能有限。岛屿狐猴，比如在马达加斯加西北海岸外的诺西贝岛发现的狐猴，面临着种群突然下降和灭绝的更高风险。诺西贝岛是两种极度濒危物种的家园——特有的诺西贝嬉猴（Lepilemur tymerlachsoni）和克莱尔倭狐猴（Microcebus mamiratra）——以及濒危的黑狐猴（Eulemur macaco）。诺西贝岛上剩余的大部分森林都受到862公顷的洛科贝国家公园的保护。为了记录诺西贝狐猴如何利用其有限的栖息地，我们在洛科贝及其周边的53个样带上进行了植被和勘察调查。我们收集了248次狐猴目击事件的树木大小、树冠覆盖、林下可见度和海拔数据。我们使用了一个空间明确的多物种占用模型来研究哪些森林结构变量对狐猴很重要。我们的结果代表了关于岛屿狐猴栖息地利用的一些首批数据。黑狐猴明显更喜欢更大的树木和林下植被较稀疏的区域。即使考虑到采样努力和地理位置，它们在洛科贝国家公园外出现的次数也明显更少。嬉猴和倭狐猴的分布与我们记录的森林结构变量无关，但它们确实呈负相关——也许是因为它们的栖息地需求不同。这些结果也强调了国家公园对保护诺西贝岛上黑狐猴种群的重要性，并引发了关于哪些因素确实影响诺西贝岛较小狐猴分布的问题。需要密切监测以防止这些种群及其提供的生态系统服务像其他岛屿狐猴那样消失。
