Nesting of Sea Turtles in the Gamba Complex of Protected Areas: First Monitoring of a Nesting Beach

Sea turtles have existed for more than 100 million years, since the Jurassic Era. The two existing families, Cheloniidae and Dermochelyidae, appeared in the Cretaceous period. Most existing species are spread over the tropical and subtropical areas of the world and play an important part in the social, cultural and economic life of numerous coastal human populations. Fossils of the family Dermochelyidae have been found dating back to the Eocene, a period of important diversity for this group. Over the last 50 million years, this diversity has been reduced and only one species has survived, the leatherback turtle (Dermochelys coriacea), with very limited geographic variation although it is the most widely-spread reptile species. As for the family Cheloniidae, five genera still exist today: the genus Natator, including one species only found in Australian waters, the flatback turtle (Natator depressus); the genus Caretta, represented by the loggerhead turtle (Caretta caretta); the genus Eretmochelys, with the hawksbill turtle (Eretmochelys imbricata); the genus Lepidochelys, with the Kemp's ridley turtle (Lepidochelys kempii), which nests exclusively in Mexico, and the olive ridley turtle (Lepidochelys olivacea); and the genus Chelonia, with the green turtle (Chelonia mydas).