Pokharel Manoj, Subba Asmit, Rai Dipa, Bhandari Simrik, Ghimirey Yadav
Department of Environmental Science Tri-Chandra Multiple Campus Kathmandu Nepal.
Central Department of Zoology Tribhuvan University Kathmandu Nepal.
Ecol Evol. 2022 Jan 13;12(1):e8512. doi: 10.1002/ece3.8512. eCollection 2022 Jan.
Once widespread throughout the tropical forests of the Indian Subcontinent, the sloth bears have suffered a rapid range collapse and local extirpations in the recent decades. A significant portion of their current distribution range is situated outside of the protected areas (PAs). These unprotected sloth bear populations are under tremendous human pressures, but little is known about the patterns and determinants of their occurrence in most of these regions. The situation is more prevalent in Nepal where virtually no systematic information is available for sloth bears living outside of the PAs. We undertook a spatially replicated sign survey-based single-season occupancy study intending to overcome this information gap for the sloth bear populations residing in the Trijuga forest of southeast Nepal. Sloth bear sign detection histories and field-based covariates data were collected between 2 October and 3 December 2020 at the 74 randomly chosen 4-km grid cells. From our results, the model-averaged site use probability ( ± ) was estimated to be 0.432 ± 0.039, which is a 13% increase from the naïve estimate (0.297) not accounting for imperfect detections of sloth bear signs. The presence of termite mound and the distance to the nearest water source were the most important variables affecting the habitat use probability of sloth bears. The average site-level detectability ( ± ) of sloth bear signs was estimated to be 0.195 ± 0.003 and was significantly determined by the index of human disturbances. We recommend considering the importance of fine-scale ecological and anthropogenic factors in predicting the sloth bear-habitat relationships across their range in the Churia habitat of Nepal, and more specifically in the unprotected areas.
懒熊曾广泛分布于印度次大陆的热带森林，但在近几十年里，其分布范围迅速缩小，局部地区灭绝。它们目前分布范围的很大一部分位于保护区之外。这些未受保护的懒熊种群面临着巨大的人类压力，但在这些地区的大部分地方，人们对它们的出现模式和决定因素知之甚少。这种情况在尼泊尔更为普遍，在那里，几乎没有关于生活在保护区之外的懒熊的系统信息。我们开展了一项基于空间重复迹象调查的单季占有率研究，旨在填补尼泊尔东南部特里朱加森林中懒熊种群的这一信息空白。2020年10月2日至12月3日期间，在74个随机选取的4公里网格单元中收集了懒熊迹象检测历史和基于实地的协变量数据。根据我们的结果，模型平均场地利用概率（±）估计为0.432±0.039，比未考虑懒熊迹象检测不完美的朴素估计（0.297）增加了13%。白蚁丘的存在和到最近水源的距离是影响懒熊栖息地利用概率的最重要变量。懒熊迹象的平均场地级可检测性（±）估计为0.195±0.003，并且显著地由人为干扰指数决定。我们建议在预测尼泊尔楚里亚栖息地整个范围内，更具体地说是在未受保护地区的懒熊与栖息地关系时，考虑精细尺度的生态和人为因素的重要性。
