Experiencing El Niño conditions during early life reduces recruiting probabilities but not adult survival.

Sergio Ancona,J Jaime Zúñiga-Vega,Hugh Drummond,Cristina Rodríguez

doi:10.1098/rsos.170076

Abstract

In wild long-lived animals, analysis of impacts of stressful natal conditions on adult performance has rarely embraced the entire age span, and the possibility that costs are expressed late in life has seldom been examined. Using 26 years of data from 8541 fledglings and 1310 adults of the blue-footed booby (Sula nebouxii), a marine bird that can live up to 23 years, we tested whether experiencing the warm waters and food scarcity associated with El Niño in the natal year reduces recruitment or survival over the adult lifetime. Warm water in the natal year reduced the probability of recruiting; each additional degree (°C) of water temperature meant a reduction of roughly 50% in fledglings' probability of returning to the natal colony as breeders. Warm water in the current year impacted adult survival, with greater effect at the oldest ages than during early adulthood. However, warm water in the natal year did not affect survival at any age over the adult lifespan. A previous study showed that early recruitment and widely spaced breeding allow boobies that experience warm waters in the natal year to achieve normal fledgling production over the first 10 years; our results now show that this reproductive effort incurs no survival penalty, not even late in life. This pattern is additional evidence of buffering against stressful natal conditions via life-history adjustments.

Highlights

Early-life exposure to stressful conditions may have short- or long-term fitness consequences [1,2]
Impacts of early-life stresses after sexual maturity, are still seldom explored [7,10,11], and because the evidence for delayed costs of poor start in life comes mainly from relatively short-term experiments in captivity, we know little about how pervasive and important these impacts are in nature [9,12]
The model including the SSTA during the natal year (SSTAn) as the only predictor of recruitment was the second best fitting model and had 21% of relative support, this model differed by 2.54 AICc units from the top-ranked model

Summary

Introduction

Early-life exposure to stressful conditions may have short- or long-term fitness consequences [1,2]. Developing offspring can sometimes get over a poor start in life, yet pay delayed costs of initial setbacks or compensatory responses triggered by poor early-life conditions [4]. Recent long-term studies show that in nature early-life stresses can elicit changes in life-history traits that allow organisms to mitigate or neutralize their potential impacts on fitness [8,9]. Impacts of early-life stresses after sexual maturity, are still seldom explored [7,10,11], and because the evidence for delayed costs of poor start in life comes mainly from relatively short-term experiments in captivity, we know little about how pervasive and important these impacts are in nature [9,12]

Methods

Results

Discussion

Conclusion