Interspecific synchrony of seabird population growth rate and breeding success
Article first published online: 30 MAY 2013
© 2013 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.
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Ecology and Evolution
Volume 3, Issue 7, pages 2013–2019, July 2013
How to Cite
Ecology and Evolution 2013; 3(7): 2013–2019
- Issue published online: 10 JUL 2013
- Article first published online: 30 MAY 2013
- Manuscript Accepted: 4 APR 2013
- Manuscript Revised: 3 APR 2013
- Manuscript Received: 18 JAN 2013
- European Research Council. Grant Number: 250189
- Community variability;
- environmental forcing;
- extreme events;
- positive correlation;
Environmental variability can destabilize communities by causing correlated interspecific fluctuations that weaken the portfolio effect, yet evidence of such a mechanism is rare in natural systems. Here, we ask whether the population dynamics of similar sympatric species of a seabird breeding community are synchronized, and if these species have similar exceptional responses to environmental variation. We used a 24-year time series of the breeding success and population growth rate of a marine top predator species group to assess the degree of synchrony between species demography. We then developed a novel method to examine the species group – all species combined – response to environmental variability, in particular, whether multiple species experience similar, pronounced fluctuations in their demography. Multiple species were positively correlated in breeding success and growth rate. Evidence of “exceptional” years was found, where the species group experienced pronounced fluctuations in their demography. The synchronous response of the species group was negatively correlated with winter sea surface temperature of the preceding year for both growth rate and breeding success. We present evidence for synchronous, exceptional responses of a species group that are driven by environmental variation. Such species covariation destabilizes communities by reducing the portfolio effect, and such exceptional responses may increase the risk of a state change in this community. Our understanding of the future responses to environmental change requires an increased focus on the short-term fluctuations in demography that are driven by extreme environmental variability.