Department of Environmental Studies, Antioch University New England, Keene, New Hampshire, United States of America.
PLoS One. 2012;7(10):e44601. doi: 10.1371/journal.pone.0044601. Epub 2012 Oct 5.
The approximately 300 (298, 95% CI: 152-581) elephants in the Lower Kinabatangan Managed Elephant Range in Sabah, Malaysian Borneo are a priority sub-population for Borneo's total elephant population (2,040, 95% CI: 1,184-3,652). Habitat loss and human-elephant conflict are recognized as the major threats to Bornean elephant survival. In the Kinabatangan region, human settlements and agricultural development for oil palm drive an intense fragmentation process. Electric fences guard against elephant crop raiding but also remove access to suitable habitat patches. We conducted expert opinion-based least-cost analyses, to model the quantity and configuration of available suitable elephant habitat in the Lower Kinabatangan, and called this the Elephant Habitat Linkage. At 184 km(2), our estimate of available habitat is 54% smaller than the estimate used in the State's Elephant Action Plan for the Lower Kinabatangan Managed Elephant Range (400 km(2)). During high flood levels, available habitat is reduced to only 61 km(2). As a consequence, short-term elephant densities are likely to surge during floods to 4.83 km(-2) (95% CI: 2.46-9.41), among the highest estimated for forest-dwelling elephants in Asia or Africa. During severe floods, the configuration of remaining elephant habitat and the surge in elephant density may put two villages at elevated risk of human-elephant conflict. Lower Kinabatangan elephants are vulnerable to the natural disturbance regime of the river due to their limited dispersal options. Twenty bottlenecks less than one km wide throughout the Elephant Habitat Linkage, have the potential to further reduce access to suitable habitat. Rebuilding landscape connectivity to isolated habitat patches and to the North Kinabatangan Managed Elephant Range (less than 35 km inland) are conservation priorities that would increase the quantity of available habitat, and may work as a mechanism to allow population release, lower elephant density, reduce human-elephant conflict, and enable genetic mixing.
沙巴州下京那巴当岸河管理大象栖息地的大约 300 头（298，95%置信区间：152-581）大象是婆罗洲大象总数（2040，95%置信区间：1184-3652）的重点亚种群。栖息地丧失和人象冲突被认为是婆罗洲象生存的主要威胁。在京那巴当岸地区，人类住区和油棕农业发展导致了强烈的破碎化过程。电围栏可以防止大象偷吃庄稼，但也会阻碍大象进入合适的栖息地斑块。我们进行了基于专家意见的最小成本分析，以模拟下京那巴当岸可获得的适宜大象栖息地的数量和配置，并将其称为“大象栖息地连接”。我们估计的可用栖息地面积为 184 平方公里，比下京那巴当岸管理大象栖息地的州大象行动计划中使用的估计面积（400 平方公里）小 54%。在高水位期间，可用栖息地减少到仅 61 平方公里。因此，在洪水期间，短期大象密度可能会飙升至每平方公里 4.83 头（95%置信区间：2.46-9.41），这是亚洲或非洲森林象中估计最高的密度之一。在严重的洪水期间，剩余大象栖息地的配置和大象密度的激增可能会使两个村庄面临与人象冲突加剧的风险。由于下京那巴当岸大象的扩散选择有限，它们容易受到河流自然干扰的影响。整个“大象栖息地连接”中有 20 个小于一公里宽的瓶颈，有可能进一步减少对适宜栖息地的获取。重建与孤立栖息地斑块和北京那巴当岸管理大象栖息地（内陆不到 35 公里）的景观连通性是保护重点，这将增加可用栖息地的数量，并可能作为一种机制，允许种群释放、降低大象密度、减少人象冲突，并实现基因混合。
