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LINKING PATCH‐USE BEHAVIOR, RESOURCE DENSITY, AND GROWTH EXPECTATIONS IN FISH
Author(s) -
Persson Anders,
Stenberg Marika
Publication year - 2006
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1890/0012-9658(2006)87[1953:lpbrda]2.0.co;2
Subject(s) - foraging , optimal foraging theory , ecology , predation , benthic zone , resource (disambiguation) , infinity , territoriality , biology , mathematics , computer science , computer network , mathematical analysis
Optimality theory rests on the assumptions that short‐term foraging decisions are driven by variation in environmental quality, and that these decisions have important implications for long‐term fitness. These assumptions, however, are rarely tested in a field setting. We linked behavioral foraging decisions in food patches with measures of environmental quality covering larger spatial (resource density) or temporal (growth parameters) scales. In 10 lakes, we measured the food density at which benthic fish give up foraging in experimental food patches (giving‐up density, GUD), quantified the biomass of benthic invertebrates, and calculated the maximum individual size ( L ∞ ) of bream ( Abramis brama L.), a typical benthivore in these lakes. We found positive relationships between resource density and both GUD and L ∞ , and a positive relationship between L ∞ and GUD. Prey characterized as vulnerable to predation contributed most to the relationships between resource density and either GUD or L ∞ . A path analysis showed that resource density and L ∞ directly explained 54% and 28%, respectively, of the variation in GUD, whereas 86% of the variation in L ∞ was explained by resource density, with mostly indirect contribution from GUD. We conclude that the short‐term foraging behavior of benthivores matched our expectations based on optimality theory by being positively linked to variables on environmental quality operating at both a larger spatial scale and a longer temporal scale.