Demographic routes to variability and regulation in bird populations

BE Saether, V Grotan, S Engen, T Coulson, PR Grant, ME Visser, JE Brommer, BR Grant, L Gustafsson, BJ Hatchwell, K Jerstad, Patrik Karell, H Pietiainen, A Roulin, OW Rostad, H Weimerskirch

Research output: Contribution to journalArticleScientificpeer-review

49 Citations (Scopus)

Abstract

There is large interspecific variation in the magnitude of population fluctuations, even among closely related species. The factors generating this variation are not well understood, primarily because of the challenges of separating the relative impact of variation in population size from fluctuations in the environment. Here, we show using demographic data from 13 bird populations that magnitudes of fluctuations in population size are mainly driven by stochastic fluctuations in the environment. Regulation towards an equilibrium population size occurs through density-dependent mortality. At small population sizes, population dynamics are primarily driven by environment-driven variation in recruitment, whereas close to the carrying capacity K, variation in population growth is more strongly influenced by density-dependent mortality of both juveniles and adults. Our results provide evidence for the hypothesis proposed by Lack that population fluctuations in birds arise from temporal variation in the difference between density-independent recruitment and density-dependent mortality during the non-breeding season.
Original languageUndefined/Unknown
Pages (from-to)
Number of pages8
JournalNature Communications
Volume7
DOIs
Publication statusPublished - 2016
MoE publication typeA1 Journal article-refereed

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