Confirmed Nesting of the Loggerhead Turtle in Corsica Michel Delaugerre1 & Cathy Cesarini2 1
Muséum national d’Histoire naturelle, Département d’Ecologie et de Gestion de la Biodiversité. Reptiles et Amphibiens. Present address: Conservatoire du littoral 3, rue Luce de Casabianca F20200 Bastia, France. (E-mail:
[email protected]) 23bis, Place Padoue 20250 Corte, France.
In the Mediterranean, loggerhead turtle (Caretta caretta) nesting sites are concentrated in the Eastern and Central basins, whereas the waters of the western basin host large number of turtles for feeding activities in oceanic and coastal habitats (Margaritoulis et al. 2003). The possibility of historic nesting of the loggerhead turtle in Corsica has been investigated by Delaugerre (1987). According to information from the Monaco Oceanographic Museum and from oral testimony, it is thought that some marine turtle nesting may have occurred on the eastern sandy coast in the first half of the 20th century. Despite a review of literature and field oral inquiries, no substantiating evidence could be unearthed. On the 20th of November 2002, local resident Eva Poli found 4 shell remains and 2 eggs scattered along 200 m of the seashore at “Plage des Lumières” on Palombaggia beach south of Porto Vecchio, southeastern Corsica. One shell was floating, the other shells and eggs were lying amongst fresh Posidonia leaves on the strandline. A turtle embryo could be seen in one of the open eggs. One egg and two shells were subsequently collected and sent to the Paris Natural History Museum for verification by Roger Bour. The egg contained an advanced stage loggerhead embryo (photograph available from the author or can be found in the SEATURTLE.ORG Image Library ). Specimens are registered in the collections of the Paris Museum: MNHN 2002-0181 (egg containing the embryo); MNHN 2002-0182 (shells). Considering their disposition, the eggs and shells probably came from a clutch deposited on the Palombaggia beach or its close surroundings even though no nest or tracks were reported. It is likely that the nest contents had been washed away by the sea from this narrow beach (15-20m wide) and some of the eggs drifted back onshore. The timing of the laying of the clutch is unknown as no reports of turtles or turtle tracks in the area were made despite the fact that the area is visited by large numbers of tourists. The site is within the border of a natural protected area (Réserve Naturelle des Bouches de Bonifacio) and part
of the future International Marine Park of CorsicaSardinia. This is the first documented evidence of a loggerhead turtle nesting both for Corsica and metropolitan France. It supports the speculation that Corsica may have once hosted a nesting population of loggerhead turtles (Delaugerre 1987). This Corsican record is one of the very rare nesting occurrence in the Western Mediterranean (Llorente et al. 1993; Tomàs et al. 2002) and the northernmost recorded nesting locality in the Mediterranean. Acknowledgements: We would like to acknowledge the assistance of R. Bour, D. Margaritoulis, L. Laurent and the Editors. DELAUGERRE, M. 1987. Status of marine turtles in the Mediterranean (with particular reference to Corsica). Vie et Milieu 37: 243-264. LLORENTE, G.A., M.A. CARRETERO, X. PASCUAL & A. PEREZ 1993. New record of a nesting Loggerhead turtle Caretta caretta in Western Mediterranean. British Herpetological Society Bulletin 42: 14-17. MARGARITOULIS, D., R. ARGANO, I. BARAN, F. BENTIVEGNA, M. N. BRADAI, J. A. CAMINAS, P. CASALE, G. DE METRIO, A. DEMETROPOULOS, G. GEROSA, B.J. GODLEY, D.A. HADDOUD, J. HOUGHTON, L. LAURENT & B. LAZAR, 2003. Loggerhead turtles in the Mediterranean Sea: present knowledge and conservation perspectives. pp 175-198 In Loggerhead Sea Turtles (A.B. Bolten and B. E. Witherington Ed.) Smithsonian Books, Washington DC. 319 pp. TOMÀS J., J.L. MONS, J.J. MARTIN, J.J. BELLIDO & J.J. CASTILLO, 2002. Study of the first reported nest of Loggerhead sea turtle, Caretta caretta, in the Spanish Mediterranean coast. Journal of the Marine Biological Association UK 82: 1005-1007.
Marine Turtle Newsletter No. 104, 2004 - Page 12
