Influence of climate and tides on the nesting behaviour of sea turtles

Abstract

A combination of climatic and environmental factors influences, and potentially guides, certain life-history processes, such as breeding. Sea turtle females may wait offshore for the optimal conditions to nest, but these environmental cues remain mostly unknown. Our aim was to identify climatic and tidal influences on nesting for leatherback turtles (Dermochelys coriacea) and try to find any specific conditions that induced them to abort the nesting attempt. To assess these issues, the beach in Pacuare Nature Reserve, on the Caribbean Costa Rica, was monitored from 2010 to 2015. Models showed that high atmospheric pressure and wind speed favoured nesting but high rainfall discouraged successful nesting; high and low tides were negatively correlated with nesting, suggesting that turtles avoid nesting when tidal cycles reach their extremes. Overall, climatic features likely related to storm episodes, and extreme tidal ranges, appear to influence leatherbacks' nesting behaviour. Therefore, the steady increase in intense storm occurrence predicted by climatic projections might represent an additional obstacle to the survival of this species.