Reproductive and ecological similarity between Caretta caretta (Linnaeus, 1758) and Eretmochelys imbricata (Linnaeus, 1766) in southern Bahia (Brazil)

Abstract

Abstract This study evaluates the reproductive and ecological similarity between loggerhead sea turtle (Caretta caretta) and Hawksbill sea turtle (Eretmochelys imbricata) two species of sea turtles on the southern coast of Bahia (Brazil) during two breeding seasons (October to April 2013 to 2015). The study covers a 10-km area composed of three beaches, Pompilho, Itacarezinho and Patizeiro beach, which are 5, 3, and 2 km long, respectively. Daily field surveys were performed for 102 days to assess patterns between the studied species, using the non-metric multidimensional scaling order and the Spearman correlation analysis to obtain the oviposition pattern of the two species. Moreover, Kruskall-Wallys tests were performed to review the differences in the number of hatchlings on the three beaches. The NMDS proved the species are very similar from an ecological perspective since as there were three clear groupings in terms of the number of hatchlings on the three beaches. With reference to the number of nests, a negative correlation was observed in the two species. Regarding the hatching activity of both species on the three beaches studied, a larger amount of C. caretta and E. imbricata hatchlings was found on Pompilho beach, followed by Patizeiro and Itacarézinho. These findings influence management strategies to reduce anthropogenic impact and contribute to the conservation of these two endangered sea turtle species.