Nesting characteristics of olive Ridley turtles (Lepidochelys Olivacea) on El Naranjo Beach, Nayarit, Mexico

We analyzed relative abundance of nesting Olive Ridley Turtles, Lepidochelys olivacea, on El Naranjo beach, Mexico during 1993–2010, as well as seasonal and spatial distribution of nesting, size of nesting females, and hatching success of nests incubated artificially in polystyrene boxes. El Naranjo beach is located in Bahia de Jaltemba, Nayarit, Mexico where a local non-governmental organization protects a total of 8.3 km of coastline on the north side of the bay. A total of 2,571 nests were protected ex situ with a mean annual 144.5 ± 77.0 (mean ± SD) protected nests (range: 48–267), and 9,457 ± 5,424, hatchlings released (range: 1,850–23,467). During the months of beach monitoring (June-November) significant differences were observed in number of nesting events per month, with maximum nesting occurring between August–October. A total of 57 nesting females were measured during 2009 (n = 18) and 2010 (n = 39). Mean curved carapace length and width was 65.5 cm and 70.7 cm, respectively. Overall hatching success was a relatively high 74.7%. We recommend further research into artificial methods of incubation as this can be an important option in maintaining some populations of sea turtles.