ESR 29:103-116 (2015)  -  DOI: https://doi.org/10.3354/esr00695

Population trends and survival of nesting green sea turtles Chelonia mydas on Aves Island, Venezuela

Marco A. García-Cruz1, Margarita Lampo1,*, Claudia L. Peñaloza2,*, William L. Kendall3, Genaro Solé4, Kathryn M. Rodríguez-Clark1

1Centro de Ecología, Instituto Venezolano de Investigaciones Científicas, Apdo. 20632, Caracas 1020-A, Venezuela
2Colorado Cooperative Fish and Wildlife Research Unit, Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, Colorado 80523, USA
3US Geological Survey, Colorado Cooperative Fish and Wildlife Research Unit, Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, Colorado 80523, USA
4FUDENA - Fundación para la Defensa de la Naturaleza, Apdo. 70776, Caracas 1071-A, Venezuela
*Corresponding authors: , ­

ABSTRACT: Long-term demographic data are valuable for assessing the effect of anthropogenic impacts on endangered species and evaluating recovery programs. Using a 2-state open robust design model, we analyzed mark-recapture data from green turtles Chelonia mydas sighted between 1979 and 2009 on Aves Island, Venezuela, a rookery heavily impacted by human activities before it was declared a wildlife refuge in 1972. Based on the encounter histories of 7689 nesting females, we estimated the abundance, annual survival, and remigration intervals for this population. Female survival varied from 0.14-0.91, with a mean of 0.79, which is low compared to survival of other populations from the Caribbean (mean = 0.84) and Australia (mean = 0.95), even though we partially corrected for tag loss, which is known to negatively bias survival estimates. This supports prior suggestions that Caribbean populations in general, and the Aves Island population in particular, may be more strongly impacted than populations elsewhere. It is likely that nesters from this rookery are extracted while foraging in remote feeding grounds where hunting still occurs. Despite its relatively low survival, the nesting population at Aves Island increased during the past 30 years from approx. 500 to >1000 nesting females in 2009. Thus, this population, like others in the Caribbean and the Atlantic, seems to be slowly recovering following protective management. Although these findings support the importance of long-term conservation programs aimed at protecting nesting grounds, they also highlight the need to extend management actions to foraging grounds where human activities may still impact green turtle populations.


KEY WORDS: Chelonia mydas · Survival · Open robust design model · Population trends


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Cite this article as: García-Cruz MA, Lampo M, Peñaloza CL, Kendall WL, Solé G, Rodríguez-Clark KM (2015) Population trends and survival of nesting green sea turtles Chelonia mydas on Aves Island, Venezuela. Endang Species Res 29:103-116. https://doi.org/10.3354/esr00695

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