Body downsizing caused by non-consumptive social stress severely depresses population growth rate
Edeline, Eric; Haugen, Thrond O.; Weltzien, Finn-Arne; Claessen, David; Winfield, Ian J.; Stenseth, Nils Chr.; Vollestad, L. Asbjorn. 2010 Body downsizing caused by non-consumptive social stress severely depresses population growth rate. Proceedings of the Royal Society of London, B, 227 (1683). 843-851. 10.1098/rspb.2009.1724Before downloading, please read NORA policies.
Chronic social stress diverts energy away from growth, reproduction and immunity, and is thus a potential driver of population dynamics. However, the effects of social stress on demographic density dependence remain largely overlooked in ecological theory. Here we combine behavioural experiments, physiology and population modelling to show in a top predator (pike Esox lucius) that social stress alone may be a primary driver of demographic density dependence. Doubling pike density in experimental ponds under controlled prey availability did not significantly change prey intake by pike (i.e. did not significantly change interference or exploitative competition), but induced a neuroendocrine stress response reflecting a size-dependent dominance hierarchy, depressed pike energetic status and lowered pike body growth rate by 23 per cent. Assuming fixed size-dependent survival and fecundity functions parameterized for the Windermere (UK) pike population, stress-induced smaller body size shifts age-specific survival rates and lowers age-specific fecundity, which in Leslie matrices projects into reduced population rate of increase (λ) by 37–56%. Our models also predict that social stress flattens elasticity profiles of λ to age-specific survival and fecundity, thus making population persistence more dependent on old individuals. Our results suggest that accounting for non-consumptive social stress from competitors and predators is necessary to accurately understand, predict and manage food-web dynamics.
|Programmes:||CEH Topics & Objectives 2009 onwards > Water > WA Topic 2 - Ecohydrological Processes > WA - 2.4 - Quantify the importance of food web structure and trophic interactions ...|
|Additional Keywords:||community interactions, corticosteroids, hypothalamo–pituitary–adrenal axis, Leslie matrix, thyroid hormones, trait-mediated interactions|
|NORA Subject Terms:||Ecology and Environment|
|Date made live:||24 Feb 2010 10:20|
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