COS 106-2 - CANCELLED - Shifting environmental predictors of phenotypes under climate change: a case study of growth in high latitude seabirds

Background/Question/Methods

Climate change is altering numerous traits in species across the globe. To predict future changes and understand the demographic and evolutionary consequences of any trait change, we need to know the environmental drivers of phenotypic change. Environmentally induced changes in the early-life growth of organisms can be particularly concerning because phenotypes expressed during early-life often predict whether or not an individual survives to adulthood, and early-life environments can have cascading impacts on adult life-history traits. In the present study, we use decadal long seabird datasets to determine specific periods of environmental variation that predict the growth of three high latitude seabird species. Specifically we asked the questions, "What are the environmental determinants of growth, have they changed over time, and how will growth change for seabirds in the future?” If we want to determine the consequences of changing environmental conditions on wild populations, we need to determine the relationship between environmental features and the traits likely to impact species' survival. We identify specific windows that predict growth using a sliding window approach and then we evaluate whether these periods changed over time. Finally, we use our identified windows to predict growth under future climate change scenarios.

Results/Conclusions

We find that the timing and type of environmental variable that predicts growth changes throughout each long-term monitoring program. The detected shifts in windows of influence likely have implications for adaptation to continued warming as parents may use these windows to predict environmental conditions during growth. We can improve predictions of phenotypic change by considering that both: 1) the timing of predictive-environmental features can change over time, and 2) the type of predictive-environmental features can change over time. The windows we identify in our study predict that climate change will decrease growth rates and bird body sizes during early-life in some species (black-legged kittiwakes Rissa tridactyla and glaucous-winged gulls Larus glaucescens), but not others (thick-billed murres Uria lomvia). Consequently, climate change is likely to decrease fledging rates in the gulls and kittiwakes where we predict poorer growth under warmer conditions. Previous work has demonstrated that the cues used by a species can vary spatially among populations, but we find that predictors might also change over time within a population. Our study highlights a need to investigate whether purported environmental determinants of traits commonly shift in a changing climate and whether such changes have implications for adaptation to future novel environments.