Conservation efforts have allowed American crocodile (Crocodylus acutus) populations to recover to the point that dispersal movements are beginning to be documented. The environmental authority of San Andres Island in Colombia reported, for the first time, the arrival of two C. acutus from unknown localities in 2012 and 2018. The former was sacrificed, and the latter was captured and kept in captivity to determining its potential origin. We used wildlife forensics to establish the origin of the animal that arrived in 2018 based on two mitochondrial genes (COI and Cytb). Additionally, five other samples from Tayrona National Natural Park (TNNP), and Salamanca Island Road Park (SIRP) were sequenced for molecular attribution of these populations to the currently described lineages. Phylogenetic and phylogeographic analyses showed that the American crocodile found in San Andrés belongs to a continental evolutionary lineage endemic to Colombia, showing also a strong genetic similarity with animals from SIRP. Thus, the most likely origin for this individual was not the nearest continental area but somewhere around the central Colombian Caribbean, located ~700 km from the island. We discuss the implication of our findings in the systematics and conservation of the species and the potential of mitochondrial DNA analysis to identify such migrants.

中文翻译：

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追踪航海者：线粒体DNA分析揭示了美洲鳄鱼（Crocodylus acutus）在整个加勒比海地区的向岛内扩散

保护工作使美洲鳄（Crocodylus acutus）种群得以恢复到开始记录分散运动的程度。哥伦比亚圣安德列斯岛的环境主管部门首次报告说，2012年和2018年有两个不知名地方的尖吻鳄到达。前者被牺牲，后者被俘虏并被囚禁以确定其潜在来源。我们使用野生动物取证法根据两个线粒体基因（COI和Cytb）确定了2018年到达的动物的起源）。此外，对来自塔罗纳国家自然公园（TNNP）和萨拉曼卡岛公路公园（SIRP）的其他五个样本进行了测序，以将这些种群的分子归因于当前描述的血统。系统发育和系统地理学分析表明，在圣安德烈斯发现的美洲鳄属于哥伦比亚特有的大陆进化谱系，也显示出与来自SIRP的动物具有很强的遗传相似性。因此，此人最有可能的起源不是最近的大陆地区，而是在哥伦比亚中部加勒比海附近某处，距该岛约700公里。我们讨论了我们的发现在该物种的系统和保护中的意义以及线粒体DNA分析识别此类移民的潜力。