Can temporal covariation and autocorrelation in demographic rates affect population dynamics in a raptor species?. Issue 4 (7th February 2020)

• Record Type: Journal Article
• Authors: Fay, Rémi; Michler, Stephanie; Laesser, Jacques; Jeanmonod, Jacques; Schaub, Michael
• Is Part Of: Ecology and evolution. Volume 10:Issue 4(2020)
• Page Start: 1959
• Page End: 1970
• Publication Date: 2020-02-07
• Subjects: covariance -- European kestrel -- Falco tinnunculus -- prey abundance -- reproduction -- serial correlation -- stochastic population growth rate -- survival; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.6027
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Theoretical studies suggest that temporal covariation among and temporal autocorrelation within demographic rates are important features of population dynamics. Yet, empirical studies have rarely focused on temporal covariation and autocorrelation limiting our understanding of these patterns in natural populations. This lack of knowledge restrains our ability to fully understand population dynamics and to make reliable population forecasts. In order to fill this gap, we used a long‐term monitoring (15 years) of a kestrel Falco tinnunculus population to investigate covariation and autocorrelation in survival and reproduction at the population level and their impact on population dynamics. Using Bayesian joint analyses, we found support for positive covariation between survival and reproduction, but weak autocorrelation through time. This positive covariation was stronger in juveniles compared with adults. As expected for a specialized predator, we found that the reproductive performance was strongly related to an index of vole abundance explaining 86% of the temporal variation. This very strong relationship suggests that the temporally variable prey abundance may drive the positive covariation between survival and reproduction in this kestrel population. Simulations suggested that the observed effect size of covariation could be strong enough to affect population dynamics. More generally, positive covariation and autocorrelation have a destabilizing effect increasing substantially the temporal variability of population size. Abstract : Empirical studies have rarely focused on temporal covariation and autocorrelation in vital rates limiting our understanding of these processes in natural populations. Our study in a kestrel population supported a positive covariation between survival and reproduction, with an age effect, but found weak evidence for temporal autocorrelation. Results suggest that prey abundance drives this positive covariation. Simulations show that the observed effect size of covariation is strong enough to increasing substantially the temporal variability of the population size.