Behavioural variability contributes to over-staying in patchy foraging

Abstract

Foragers often systematically deviate from rate-maximizing choices in two ways: accuracy and precision. That is, they use suboptimal threshold values and also show variability in their application of those thresholds. We hypothesized that these biases are related and, more specifically, that foragers' widely known accuracy bias––over-staying––could be explained, at least in part, by their imprecision. To test this hypothesis, we analysed choices made by three rhesus macaques in a computerized patch foraging task. Confirming previously observed findings, we found high levels of variability. We then showed, through simulations, that this variability changed optimal thresholds, meaning that a forager aware of its own variability should increase its leaving threshold (i.e. over-stay) to increase performance. All subjects showed thresholds that were biased in the predicted direction. These results indicate that over-staying in patches may reflect, in part, an adaptation to behavioural variability.

The size dependency of foraging behaviour: an empirical test performed on aquatic amphipods

“…New experiments involving accurate measurements of the individual forager's metabolic rate are needed to better understand the relationship between body sizes, energy requirements, and patch exploitation behaviour. In addition, the role of individual personality (i.e., consistent difference between individuals in their behaviour across time and context, Dingemanse et al 2010) should be investigated, because it could modulate the effect of size on resource exploitation (Cash-Padgett and Hayden, 2020;Cornwell et al 2020) and foragers' movement patterns (DiNuzzo and Griffen 2020;Milles et al 2020).…”

Quitting while you’re ahead: Patch foraging and temporal cognition.

“…Recently, Cash-Padgett and Hayden (2020) have generalized the idea of overstaying as a compensatory strategy for minimizing the cost of irreducible behavioral variability—whatever the cause of that variability might be. Results from timing experiments support the idea that subjects alter their behavioral strategies in response to how costly errors in timing are.…”

Sex differences in patch-leaving foraging decisions in rats

“…Patch foraging decisions have been studied in the laboratory in species including humans (Constantino & Daw, 2015; Hall-McMaster et al, 2021, 2021; Heron et al, 2020; Kolling et al, 2012), non-human primates (Barack et al, 2017, 2022; Blanchard & Hayden, 2015; Cash-Padgett & Hayden, 2020; Eisenreich et al, 2019; Hayden et al, 2011; Turrin et al, 2017), and rodents (Cazettes et al, 2022; Kane et al, 2017, 2019, 2022; Lottem et al, 2018; Vertechi et al, 2020). Frequently, such studies simulate foraging decisions in ways that require relatively little movement from subjects.…”

“…To optimize food intake rate, foragers must select patch residence time between the extremes of remaining in patches for too long (thereby enduring low rates of reward when replete patches exist elsewhere) and leaving patches too quickly (thereby spending most available foraging time travelling between patches). Patch foraging decisions have been studied in the laboratory in species including humans (Constantino & Daw, 2015;Hall-McMaster et al, 2021Heron et al, 2020;Kolling et al, 2012), non-human primates (Barack et al, 2017(Barack et al, , 2022Blanchard & Hayden, 2015;Cash-Padgett & Hayden, 2020;Eisenreich et al, 2019;Hayden et al, 2011;Turrin et al, 2017), and rodents (Cazettes et al, 2022;Kane et al, 2017Kane et al, , 2019Kane et al, , 2022Lottem et al, 2018;Vertechi et al, 2020). Frequently, such studies simulate foraging decisions in ways that require relatively little movement from subjects.…”