Journal Article

Micro-evolutionary response of spring migration timing in a wild seabird

Haest, Birgen, Bouwhuis, Sandra, Teplitsky, Céline, Moiron, Maria, Charmantier, Anne

2024

Overview

In the context of rapid climate change, phenological advance is a key adaptation for which evidence is accumulating across taxa. Among vertebrates, phenotypic plasticity is known to underlie most of this phenological change, while evidence for micro-evolution is very limited and challenging to obtain. In this study, we quantified phenotypic and genetic trends in timing of spring migration using 8,032 dates of arrival at the breeding grounds obtained from observations on 1,715 individual common terns (Sterna hirundo) monitored across 27 years, and tested whether these trends were consistent with predictions of a micro-evolutionary response to selection. We observed a strong phenotypic advance of 9.3 days in arrival date, of which c. 5% was accounted for by an advance in breeding values. The Breeder’s equation and Robertson’s Secondary Theorem of Selection predicted qualitatively similar evolutionary responses to selection, and these theoretical predictions were largely consistent with our estimated genetic pattern. Overall, our study provides rare evidence for micro-evolution underlying (part of) an adaptive response to climate change in the wild, and illustrates how a combination of adaptive micro-evolution and phenotypic plasticity facilitated a shift towards earlier spring migration in this free-living population of common terns. Lay Summary Empirical evidence for evolutionary change underlying vertebrate adaptation to current global change is very rare. This may be due to phenotypic plasticity being the main mechanism underlying adaptation, or to challenges associated with the empirical testing of genetic changes in the wild, in particular data limitations. In this study, we tested whether an observed phenotypic advance in the timing of arrival from spring migration in a wild seabird population was due to an evolutionary response (i.e., genetic change) and/or to phenotypic plasticity or other non-genetic effects. To do so, we applied a bivariate “animal model” to a 27-year data set from a pedigreed population of common terns located at the North Sea coast of Germany. We found an evolutionary response to selection favoring earlier arriving individuals. Additionally, we could show that two different theoretical models predict a qualitatively similar evolutionary response as the one we estimated, both in terms of direction and magnitude. As such, our study provides a rare empirical case where estimated and predicted evolutionary responses agree, and suggests an evolutionary response in the timing of avian spring migration, although it played a smaller role than phenotypic plasticity in the common tern response to rapid climate change. Overall, these findings show the use of disentangling the relative, and often complementary, contributions of plastic and evolutionary changes to better understand adaptive processes and predict responses to future changes.

• Publisher: Oxford University Press,Wiley Open Access ; Oxford University Press
• Subject: Animal biology / Bioclimatology / Biodiversity / Climate change / Ecology, environment / Evolution / Life Sciences / Phenotypic plasticity / Populations and Evolution / Trends / Vertebrate Zoology