Protected areas provide some of the last refuges for Asian elephants in the wild. Managing these areas for elephants will be critical for elephant conservation. Scientists know little about elephant habitat use in Asia and how invasive species or livestock grazing influence habitat use. We studied these issues in two protected areas in Sri Lanka, Udawalawe National Park and Hurulu Eco-Park. These areas contain some of Sri Lanka's largest remaining grasslands. These grasslands are threatened by the invasive and toxic shrub, , and are used for illegal livestock grazing. To measure habitat use by elephants and livestock, we conducted dung surveys along over 50 km of transects stratified across grassland, scrub, and forest. We surveyed 159 vegetation plots along these transects to assess plant composition, and mapped habitat types based on satellite images. We used mixed-effect models to determine the relative importance of habitats, livestock presence, and plant associations for elephant use. Elephant presence was greatest in scrub and grassland habitats, positively associated with both livestock presence and short graminoids, and unaffected by , which was widespread but at low densities. Given the importance of these areas to elephants, we recommend a precautionary management approach that focuses on curbing both illegal grazing and the spread of .

中文翻译：

---

非法放牧和入侵马缨丹对亚洲象栖息地利用的影响

保护区为亚洲象在野外提供了最后的庇护所。管理这些大象区域对于大象保护至关重要。科学家们对亚洲大象栖息地的利用以及入侵物种或牲畜放牧如何影响栖息地的利用知之甚少。我们在斯里兰卡的两个保护区——乌达瓦拉维国家公园和胡鲁鲁生态公园——研究了这些问题。这些地区包含斯里兰卡现存最大的一些草原。这些草原受到入侵性有毒灌木的威胁，并被用来非法放牧牲畜。为了测量大象和牲畜对栖息地的利用情况，我们沿着横跨草原、灌木丛和森林的 50 多公里横断面进行了粪便调查。我们调查了这些样带沿线的 159 个植被地块，以评估植物组成，并根据卫星图像绘制了栖息地类型图。我们使用混合效应模型来确定栖息地、牲畜存在和植物关联对大象使用的相对重要性。大象在灌木丛和草原栖息地的数量最多，与牲畜的存在和短禾本科植物呈正相关，并且不受大象的影响，大象分布广泛，但密度较低。鉴于这些地区对大象的重要性，我们建议采取预防性管理方法，重点遏制非法放牧和大象传播。