caa a22 4500 465782957 CHVBK 20180323112000.0 cr unu---uuuuu 170327e19900801xx s 000 0 eng 10.1007/BF00168457 doi (NATIONALLICENCE)springer-10.1007/BF00168457 Inadvertent errors and error-constrained optimization: fallible foraging by bluegill sunfish [Elektronische Daten] [P. Crowley, D. DeVries, A. Sih] Summary: When the expected reward rate is continuously reduced by foraging in a patch, foragers may adjust their patch persistence times to maximize the average long-term reward rate. The marginal-value model predicts the optimal persistence time for this situation. But real foragers may be unable consistently to achieve a precise persistence time. If the costs of under- and over-persistence differ, or if the resulting distribution of persistence times is skewed, a sufficiently broad persistence-time distribution can substantially shift the actual optimum. Moreover, this "error-constrained” optimum depends on the variable used by the forager to decide when to leave the patch (e.g., on persistence time per se, cumulative number of prey eaten, or instantaneous feeding rate). Here, we analyze laboratory data from bluegill sunfish (Lepomis macrochirus) foraging on larval-midge prey (Chironomus riparius) in patches of artificial vegetation, and we explore some wider implications of a model that seems to fit the data. The bluegills stayed 4%-157% longer in patches than predicted by the marginal value theorem. This behavior closely matched numerical solutions based on the observed variability of persistence times and the assumption that departures were cued by instantaneous feeding rate. On the other hand, the other two mechanisms that we investigated (i.e., persistence time per se and cumulative number of prey eaten) predict weak to moderate underpersistence relative to the marginal-value predictions, patterns quite unlike those observed. Surprisingly, the instantaneous-rate mechanism yields roughly a 10% lower over-all maximal reward rate than would either of the other two departure-cuing mechanisms. The modeling analysis documents the considerable sensitivity of our results to (1) the departure-cuing mechanism, (2) the shape of the frequency distribution of the departure-cuing variable, (3) the way that the shape of this distribution shifts as its mean changes, and (4) the magnitudes of the foraging parameters. Springer-Verlag, 1990 Crowley P. Behavioral and Evolutionary Ecology Research Group, T.H. Morgan School of Biological Sciences, University of Kentucky, 40506, Lexington, KY, USA aut DeVries D. Department of Zoology, The Ohio State University, 43210, Columbus, OH, USA aut Sih A. Behavioral and Evolutionary Ecology Research Group, T.H. Morgan School of Biological Sciences, University of Kentucky, 40506, Lexington, KY, USA aut Behavioral Ecology and Sociobiology Springer-Verlag 27/2(1990-08-01), 135-144 0340-5443 27:2<135 1990 27 265 https://doi.org/10.1007/BF00168457 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00168457 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Crowley P. Behavioral and Evolutionary Ecology Research Group, T.H. Morgan School of Biological Sciences, University of Kentucky, 40506, Lexington, KY, USA aut NATIONALLICENCE 700 1- DeVries D. Department of Zoology, The Ohio State University, 43210, Columbus, OH, USA aut NATIONALLICENCE 700 1- Sih A. Behavioral and Evolutionary Ecology Research Group, T.H. Morgan School of Biological Sciences, University of Kentucky, 40506, Lexington, KY, USA aut NATIONALLICENCE 773 0- Behavioral Ecology and Sociobiology Springer-Verlag 27/2(1990-08-01), 135-144 0340-5443 27:2<135 1990 27 265 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer