a1 Université Paris-Sud, Laboratoire Ecologie, Systématique et Evolution, UMR 8079, Orsay F-91405, France, and CNRS, Orsay F-91405, France.
a2 Université Paris-Sud, Orsay, France, and Association RENATURA, Pointe-Noire, Congo.
a3 Association RENATURA, Albens, France and Pointe-Noire, Congo.
Six marine turtle species are reported from the coastal waters of the Republic of the Congo. Among them, nesting by the Critically Endangered leatherback Dermochelys coriacea and Endangered olive ridley Lepidochelys olivacea marine turtles occurs annually from September to April on Congolese beaches. We developed a methodology to model the nesting season of marine turtles and apply it to the time series of nest counts for six nesting beaches monitored over 2–4 years. There is a peak of nesting activity in early January for leatherback turtles and early December for olive ridley turtles. We show a decline of olive ridley nests during this period whereas leatherback nesting increased, and propose that differential threats for these two species explain such a contrasted pattern.
(Received September 18 2007)
(Reviewed December 03 2007)
(Accepted March 04 2008)
p1 Also at: Département de Systématique et Evolution, Muséum National d'Histoire Naturelle de Paris, Paris, France.
This paper contains supplementary material that can be found online at http://journals.cambridge.org