Some like it hot: Effect of environment on population dynamics of a small tropical seabird in the Caribbean region

Abstract

An understanding of how environmental changes affect life history traits and populatio dynamics is essential for predicting the effects of climate change, managing ecosystems, and determinin how species and habitats can best be preserved. This applies particularly to seabirds, which, as to marin predators, are often considered as indicators of marine ecosystem changes. Most studies have s far been conducted in polar or temperate regions. However, important changes in the functioning of tropica marin ecosystems have been reported, but the responses of top predators remain poorly known. Thi study focused on a tropical seabird, Audubon's shearwater Puffinus lherminieri, analyzing the relationship between climate change and the survival of adults, nesting success, and population dynamics. The populatio studied breeds in Martinique, in the south of the Caribbean region, which is strongly influenced by th Amazon and Orinoco rivers. A data set for the period 1995 to 2014 was used to estimate the survival by ag classes and breeding success and to determine which climate variables most affected demographic parameters The population dynamics were modeled to predict the future population growth rates in respons to climate change. The annual adult survival rate increased over the last 20 years, currently standing a 94% for adult birds more than 6 years old. Adult survival increased with sea surface temperature (SST during the nonbreeding season as well as with Amazon River discharge, although the latter with a lag o 1 year. The effect of SST was explained by the positive relationship between SST and chlorophyll a durin years of high discharge from the Amazon and Orinoco. The population decreased between 1995 and 200 at a rate of 3% per year and then increased between 2008 and 2014 at a rate of 7% per year. The increas in adult survival observed should continue as temperatures increase in the future, and the populatio models predicted a stable or increasing population over the next 50 years (λ = 1.018). These results contras with the negative effect of increasing SST on seabird populations found in temperate and polar regions emphasizing the need to study the impact of climate change on tropical seabirds. Copyright: