Effect of human-mediated migration and hybridization on the recovery of the American crocodile in Florida (USA)

• Published in: Conservation genetics Vol. 12; no. 2; pp. 449 - 459
• Main Authors: Rodriguez, David, Forstner, Michael R. J, Moler, Paul E, Wasilewski, Joseph A, Cherkiss, Michael S, Densmore III, Llewellyn D
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.04.2011; Springer Netherlands; Springer Nature B.V
• Subjects: Animal Genetics and Genomics; Animal populations; Aquatic reptiles; Biodiversity; Biomedical and Life Sciences; Conservation Biology/Ecology; Crocodiles; Crocodylus; Crocodylus acutus; Ecology; Endangered & extinct species; Endangered species; Endangered species recovery; Evolutionary Biology; Genetic markers; Human-mediated migration; Hybridization; Life Sciences; Plant Genetics and Genomics; Population genetics; Population number; Population structure; Research Article; Wildlife conservation; ASW, USA, Florida; ASW, Caribbean Sea, Greater Antilles; Latin America; Endangered species recovery; Hybridization; Human-mediated migration; Population genetics
• ISSN: 1566-0621; 1572-9737
• DOI: 10.1007/s10592-010-0153-1

The American crocodile (Crocodylus acutus) is a large apex predator with an extensive but fragmented range. Crocodylus acutus suffered a population crash and was almost extirpated from Florida (USA) during the 1970s; however, in 2007 it was federally downlisted from endangered to threatened based on an increase of suitable habitat and a growing population. A genetic assessment of this population has not been performed even though foreign crocodiles have been released into Florida waters. Herein, we use mitochondrial and nuclear DNA markers to characterize relationships among American crocodiles along the southern coast of Florida and reference samples from other countries. We detected inter- and intra-specific hybridization and unexpected population structure attributed to human-mediated migration of crocodiles from Latin America and the Greater Antilles. Our results suggest that the population size of crocodiles actually native to Florida should be reevaluated, particularly in light of ongoing admixture in this population. We reemphasize the utility of genetic markers in conservation and management programs for endangered species; especially those that can hybridize with closely related congeners. The American crocodile in Florida has recovered owing to successful conservation initiatives, but a long-term management protocol that takes genetic data into account is still needed.