Abstract Some of the most arid environments inhabited by the Eurasian otter (Lutra lutra) are the river systems draining the southern slopes of the High Atlas Mountains into the Sahara Desert, where we have studied otter distribution, habitat use and feeding ecology. We found signs of otter presence in 61% of 80 sampled sites. The species was widespread at intermediate elevations within the study area, being rarer at high altitudes (above 2000 m a.s.l.) and, especially, in the arid lowlands. The intensity of habitat use, estimated from spraint counts, also peaked at intermediate elevations. Otter diet, described through the analysis of 554 spraints, was dominated by fish in general (found in 97% of the spraints) and Luciobarbus barbels in particular (86% of spraints). The otter positively selected barbels of intermediate sizes (100–160 mm in length), avoiding the smallest size classes and consuming larger ones according to their availability. Our results suggest that otter may be vulnerable to the harsh environmental conditions in arid areas. This aridity-driven vulnerability is expected to increase in the area and to expand to other peri-Mediterranean regions in the future.

中文翻译：

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沙漠水獭：摩洛哥干旱河流的分布、栖息地利用和饲养生态

摘要 欧亚水獭 (Lutra lutra) 栖息的一些最干旱的环境是将高阿特拉斯山脉南坡排入撒哈拉沙漠的河流系统，我们在那里研究了水獭的分布、栖息地利用和摄食生态。我们在 80 个采样点中的 61% 发现了水獭存在的迹象。该物种在研究区内的中等海拔地区广泛分布，在高海拔地区（海拔 2000 米以上），尤其是在干旱的低地地区较为罕见。根据扭伤计数估计的栖息地使用强度也在中间海拔达到峰值。通过对 554 次扭伤的分析描述的水獭饮食主要以鱼为主（在 97% 的扭伤中发现），尤其是 Luciobarbus 触须（86% 的扭伤）。水獭积极选择中等尺寸（长度为 100-160 毫米）的触须，避免使用最小尺寸等级并根据其可用性消耗较大尺寸等级。我们的研究结果表明，水獭可能容易受到干旱地区恶劣环境条件的影响。预计这种干旱驱动的脆弱性将在该地区增加，并在未来扩展到其他地中海沿岸地区。