Genetic diversity in Mexican wild populations of the Great Curassow (Crax rubra)

Abstract

Abstract The Great Curassow (Crax rubra) is a Neotropical bird with a wide distribution; it is classified under different threat categories and is listed as a vulnerable species by the IUCN. The Official Mexican Standard, the NOM-059-SEMARNAT-2010, indicates that the Great Curassow is a threatened species, and the subspecies Crax rubra griscomi, which is restricted to the island of Cozumel, is classified as critically endangered. Habitat loss and fragmentation, hunting, overexploitation, and illegal trade are among the main factors that have placed the bird at an endangered status. The objective of the present study was to determine the genetic structure and variation of the species within the Mexican populations of Crax rubra by using three mitochondrial markers, and one nuclear marker (COI, ND2, Cyt b, and MUSK). We used 47 samples obtained by noninvasive collection (feathers) including the two different color phases of the female plumage: dark brown and barred (rare in Mexico). Gene flow between the remaining populations is recent and extensive, even between the continental and the island population (C. r. griscomi). The results indicate that the subspecies C. r. rubra and C. r. griscomi do not present a marked genetic differentiation because the second exhibits an exclusive haplotype and a shared haplotype. With this study, we provide the first genetic-geographic approximation of the curassow in Mexico, where a gradual geographic differentiation is observed between the western and eastern populations of the Isthmus of Tehuantepec, and we provide a baseline for future studies. Finally, the information obtained indicates that important genetic diversity persists in the Mexican populations of the Great Curassow and that sufficient conservation within the ecosystems of these subspecies can be obtained by protecting them from overexploitation and by conserving and restoring their habitat.