The Socotra Archipelago is a unique hotspot of biodiversity, particularly for terrestrial reptiles (28 endemic out of 31 native species) whose ecology is known only in general terms. We describe the ecological preference and the daily activity of 21 species of terrestrial reptiles, geckos, lizards, skinks, snakes and chameleon, from the largest island of the archipelago. The database includes 6950 records collected by 260 standardized transects from 2007 to 2013. The sister species Haemodracon riebeckii–H. trachyrhinus with very distinct body sizes, overlapped in their distribution but segregated by habitat and substrate. Three pairs of sister species with great phylogenetic affinity and similar morphology (Pristurus insignis–P. insignoides; Pristurus guichardi–P. obsti; Hemidactylus dracaenacolus–H. granti) were only partially segregated by distribution, habitat, substrate and body size, in the order of decreasing frequency. On the contrary, the other, phylogenetically more distant species of geckos, widely distributed and less similar in morphology, overlapped completely in their habitat use and distributional range. Such patterns suggest that strictly related species reduced their competition by segregation in different habitats and temporal niches and by non-overlapping distribution within the relatively small island of Socotra. On the other hand, the activity rhythm was similar within each genus. The unique biodiversity of Socotra endured up to present, thanks to a human impact lower than for most other inhabited islands, but the pace of change has accelerated recently. Conservation measures are urgent, particularly for the species of endemic geckos with a distribution range as small as 10 km².

中文翻译：

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索科特拉地方性爬行动物群落的生态偏好

索科特拉群岛是独特的生物多样性热点，特别是对于陆地爬行动物（31个本地物种中的28个地方性物种）而言，其生态学仅是众所周知的。我们描述了来自该群岛最大岛屿的21种陆地爬行动物，壁虎，蜥蜴，石龙子，蛇和变色龙的生态偏好和日常活动。该数据库包括2007年至2013年由260个标准化样面收集的6950条记录。其姊妹物种Haemodracon riebeckii – Hach trachyrhinus体型非常不同，分布重叠，但按栖息地和底物分隔。三对姐妹物种，具有很强的系统发育亲和力和相似的形态（Pristurus insignis –P. insignoides; Pristurus guichardi – P. obsti；Hemidactylus dracaenacolus – H. Granti）仅按分布，栖息地，基质和体型按频率递减的顺序部分隔离。相反，另一个在系统发育上距离较远的壁虎物种，分布较广，形态上不太相似，它们在栖息地的使用和分布范围上完全重叠。这种模式表明，严格相关的物种通过在不同生境和时空生态位中的隔离以及在相对较小的索科特拉岛中的非重叠分布而减少了竞争。另一方面，每个属内的活动节律相似。由于对人类的影响低于对其他大多数有人居住的岛屿的影响，索科特拉岛独特的生物多样性一直持续到现在，但变革的步伐最近有所加快。保护措施很紧急，²。