Phylogeography of the American crocodile, Crocodylus acutus (Crocodylia: Crocodylidae) in Colombia: a conservation perspective

Abstract

Abstract Crocodylus acutus is the most widely distributed crocodile in the Neotropics, playing a key role in the ecosystems it inhabits. However, unsustainable use and habitat degradation have depleted its populations across its range. In Colombia, it is classified as Endangered by local authorities, and a legislative framework for its protection has been created, implementing hunting bans and breeding programmes. Successful implementation of these programmes depends on the existence of baseline genetic information, which is currently insufficient for the species. We assess the genetic diversity, phylogeography, and demographic patterns of the American crocodile in Colombia based on three mitochondrial markers (cox1, cytb, and trnP/trnF/D-Loop) and propose actions for its management and conservation. We processed 33 American crocodile samples from both wild and captive populations and performed genetic variability, phylogenetic, phylogeographical, and neutrality tests, including previously reported sequences. We found evidence of high genetic variability in Colombia, the existence of clearly differentiated mitochondrial phylogenetic clades, and possible human-influenced or stochastic demographic variation events. We propose guidelines for the translocation of American crocodiles based on our findings and present evidence of possible dispersal events in the Caribbean and Magdalena regions. Finally, we suggest the implementation of management units and identify research priorities for future work.