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Behavioural trade‐offs between growth and mortality explain evolution of submaximal growth rates
Author(s) -
BIRO PETER A.,
ABRAHAMS MARK V.,
POST JOHN R.,
PARKINSON ERIC A.
Publication year - 2006
Publication title -
journal of animal ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.134
H-Index - 157
eISSN - 1365-2656
pISSN - 0021-8790
DOI - 10.1111/j.1365-2656.2006.01137.x
Subject(s) - predation , foraging , trout , biology , trade off , ecology , rainbow trout , growth rate , fishery , fish <actinopterygii> , geometry , mathematics
Summary1 The importance of body size and growth rate in ecological interactions is widely recognized, and both are frequently used as surrogates for fitness. However, if there are significant costs associated with rapid growth rates then its fitness benefits may be questioned. 2 In replicated whole‐lake experiments, we show that a domestic strain of rainbow trout (artificially selected for maximum intrinsic growth rate) use productive but risky habitats more than wild trout. Consequently, domestic trout grow faster in all situations, experience greater survival in the absence of predators, but have lower survival in the presence of predators. Therefore, rapid growth rates are selected against due to increased foraging effort (or conversely, lower antipredator behaviour) that increases vulnerability to predators. In other words, there is a behaviourally mediated trade‐off between growth and mortality rates. 3 Whereas rapid growth is beneficial in many ecological interactions, our results show the mortality costs of achieving it are large in the presence of predators, which can help explain the absence of an average phenotype with maximized growth rates in nature.