Abstract Crocodiles play important roles in many ecosystems, but their populations worldwide are threatened by human exploitation and habitat destruction. We studied ontogenetic changes in habitat use and seasonal activity patterns in a population of Nile crocodiles (Crocodylus niloticus) inhabiting the Lake Albert Delta Wetland System, a Ramsar Site of international importance in Murchison Falls National Park of western Uganda. A total of 186 crocodile observations were made from monthly surveys of five transects during October 2017 to September 2018. Crocodiles exhibited a marginally bi-modal seasonal pattern, with the fewest observations from July to August and October to November, and the highest observations from January to February and April to May. Crocodiles were most frequently encountered along the north shore of the delta, especially on riverbanks with woody vegetation, followed by Cyperus papyrus-Vossia dominated habitats, while crocodiles were infrequently observed on islands and muddy banks. Habitat niche breadth was narrowest in hatchlings and widest in sub-adults, with juveniles and large adults exhibiting intermediate values. Overlap in habitat resource use across size classes was generally high, with the lowest overlap between hatchlings and juveniles, and the highest between large and sub-adult crocodiles. Our study on Nile crocodiles in the Lake Albert delta provides insights into habitat partitioning among different demographic segments of this population that can be utilized to improve its management in one of Africa’s Great Lakes by spatially and temporally focusing conservation efforts on the most used habitats and seasonal aggregations, respectively.

中文翻译：

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东非艾伯特湖三角洲尼罗鳄（Crocodylus niloticus）的个体发育栖息地利用和季节性活动

摘要 鳄鱼在许多生态系统中发挥着重要作用，但它们在世界范围内的种群受到人类开发和栖息地破坏的威胁。我们研究了栖息在阿尔伯特湖三角洲湿地系统的尼罗河鳄鱼种群的栖息地利用和季节性活动模式的个体发生变化，该湿地系统是乌干达西部默奇森瀑布国家公园中具有国际重要性的拉姆萨尔湿地。2017 年 10 月至 2018 年 9 月对 5 个样带进行月度调查，共进行了 186 条鳄鱼观测。鳄鱼呈现出轻微的双峰季节性模式，其中 7 月至 8 月和 10 月至 11 月的观测最少，1 月的观测最多到二月和四月到五月。鳄鱼最常出现在三角洲的北岸，特别是在有木本植被的河岸上，其次是莎草纸莎草-Vossia 占主导地位的栖息地，而在岛屿和泥泞的河岸上很少观察到鳄鱼。生境生态位宽度在幼体中最窄，在亚成体中最宽，幼体和大型成体表现出中间值。不同体型的栖息地资源利用重叠度普遍较高，幼鳄鱼和幼鳄鱼之间的重叠度最低，大型鳄鱼和亚成年鳄鱼之间的重叠度最高。我们对艾伯特湖三角洲的尼罗河鳄鱼的研究提供了对该种群不同人口群体之间栖息地划分的见解，可用于通过在空间和时间上将保护工作重点放在最常用的栖息地和季节性地来改善其在非洲五大湖之一的管理聚合，分别。