Nesting of green turtles (Chelonia mydas) at Ascension Island, South Atlantic

Abstract A detailed survey of the nesting by green turtles ( Chelonia mydas ) on Ascension Island (7°57′ S, 14°22′ W) was conducted between 1 December 1998 and 1 October 1999. During this period there was a total estimate of 36,036 marine turtle nesting activities, resulting in the deposition of an estimated 13,881 clutches (95% confidence limits 13,092–14,660). These data suggest that 2–3 times more turtles nested than when previous detailed surveys were undertaken in the 1970′s. The peak of nesting was in March, with 95% of nesting activity being recorded between 4 January and 18 May. Possible reasons for the evolution of the seasonality of nesting are discussed. Individual beaches varied greatly in density of nesting activities (range=534–10,001 activities/km; mean=6204 activities/km), density of nests (range=213–5200 nests/km; mean=2390 nests/km) and the proportion of nesting activities resulting in nests (nesting success; range=0.13–0.52; mean=0.39).

[1]  J. Mortimer.  The Influence of Beach Sand Characteristics on the Nesting Behavior and Clutch Survival of Green Turtles (Chelonia mydas) , 1990 .

[2]  M. Miyamoto,et al.  Phylogeography and population structure of the Atlantic and Mediterranean green turtle Chelonia mydas: a mitochondrial DNA control region sequence assessment , 1996, Molecular ecology.

[3]  J. Mortimer,et al.  Twenty‐Six Years of Green Turtle Nesting at Tortuguero, Costa Rica: An Encouraging Trend , 1999 .

[4]  Christine M. Bunck,et al.  Fifty-year trends in a box turtle population in Maryland , 1999 .

[5]  C. Limpus,et al.  GLOBAL POPULATION STRUCTURE AND NATURAL HISTORY OF THE GREEN TURTLE (CHELONIA MYDAS) IN TERMS OF MATRIARCHAL PHYLOGENY , 1992, Evolution; international journal of organic evolution.

[6]  M. Marcovaldi,et al.  Marine turtles of Brazil:the history and structure of Projeto TAMAR-IBAMA , 1999 .

[7]  K. Bjorndal.  Biology and Conservation of Sea Turtles , 1982 .

[8]  J. Mortimer,et al.  Reproduction and migrations of the Ascension Island green turtle (Chelonia mydas) , 1987 .

[9]  G. Hays,et al.  Inter- and Intra-Beach Thermal Variation for Green Turtle Nests on Ascension Island, South Atlantic , 1995, Journal of the Marine Biological Association of the United Kingdom.

[10]  R. Marsh,et al.  The navigational feats of green sea turtles migrating from Ascension Island investigated by satellite telemetry , 1998, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[11]  B. Schroeder,et al.  Population Surveys (ground and aerial) on Nesting Beaches , 1999 .

[12]  A. Carr.  The Ascension Island Green Turtle Colony , 1975 .

[13]  R. Ackerman.  The Nest Environment and the Embryonic Development of Sea Turtles , 1997 .

[14]  Peter L. Lutz,et al.  The Biology of Sea Turtles , 1998 .

[15]  P. Ponganis,et al.  Diving and foraging behavior of leatherback sea turtles (Dermochelys coriacea) , 1989 .

[16]  R. A. Luxmoore,et al.  The green turtle and hawksbill (Reptilia: Cheloniidae) : world status, exploitation and trade , 1990 .

[17]  G. Hays,et al.  Long-term thermal conditions on the nesting beaches of green turtles on Ascension Island , 1999 .

[18]  A. Carr,et al.  The ecology and migrations of sea turtles 5:Comparative features of isolated green turtle colonies , 1962 .

[19]  P. Pritchard.  Post-Nesting Movements of Marine Turtles (Cheloniidae and Dermochelyidae) Tagged in the Guianas , 1976 .

[20]  A. Meylan,et al.  THE ECOLOGY AND MIGRATIONS OF SEA TURTLES , 7 . THE WEST CARIBBEAN GREEN TURTLE COLONY , 2004 .

[21]  M. Miyamoto,et al.  Genetic composition of a green turtle (Chelonia mydas) feeding ground population: evidence for multiple origins , 1998 .

[22]  N. Nicholls,et al.  The Southern Oscillation regulates the annual numbers of green turtles (Chelonia mydas) breeding around Northern Australia , 1988 .

[23]  James D. Lawrey,et al.  Statistical Methods in Biology , 1996 .

[24]  K. Eckert,et al.  Research and Management Techniques for the Conservation of Sea Turtles , 1999 .

[25]  B. Godley,et al.  Population and nesting ecology of the Green Turtle, Chelonia mydas, and the Loggerhead Turtle, Caretta caretta, in northern Cyprus , 1996 .

[26]  J. P. Schulz.  Sea turtles nesting in Surinam , 1975 .