ESR prepress abstract  -  doi: 10.3354/esr00098

ABSTRACT: We used a long term tagging dataset to investigate alterations in the reproductive ecology of leatherback turtles Dermochelys coriacea in Pacific Costa Rica in response to changes in climatic conditions. We calculated the remigration interval and reproductive output of individual turtles to determine if these variables changed after a transition from El Niño-dominated to La Niña-dominated conditions. The reproductive schedule of turtles was changed after the end of El Niño conditions, such that the number of turtles nesting with short remigration intervals increased, but their reproductive output was unchanged. In addition, remigration intervals of individuals that nested before, during and after the transition were altered coincident with the oceanic productivity changes caused by the climatic events. We modelled this data to show that a dominance of ‘bad’ El Niño conditions reduces population feasibility through increases in the age at maturity and remigration interval, while a dominance of ‘good’ La Niña conditions causes the reverse. We propose that climate may similarly manifest in changes in the reproduction and migration of individual animals of other Pacific vertebrate predators to affect their population feasibility.