Among-individual differences in foraging modulate resource exploitation under perceived predation risk

Abstract

Foraging is risky and involves balancing the benefits of resource acquisition with costs of predation. Optimal foraging theory predicts where, when and how long to forage in a given spatiotemporal distribution of risks and resources. However, significant variation in foraging behaviour and resource exploitation remain unexplained. Using single foragers in artificial landscapes of perceived risks and resources with diminishing returns, we aimed to test whether foraging behaviour and resource exploitation are adjusted to risk level, vary with risk during different components of foraging, and (co)vary among individuals. We quantified foraging behaviour and resource exploitation for 21 common voles (Microtus arvalis). By manipulating ground cover, we created simple landscapes of two food patches varying in perceived risk during feeding in a patch and/or while travelling between patches. Foraging of individuals was variable and adjusted to risk level and type. High risk during feeding reduced feeding duration and food consumption more strongly than risk while travelling. Risk during travelling modified the risk effects of feeding for changes between patches and resulting evenness of resource exploitation. Across risk conditions individuals differed consistently in when and how long they exploited resources and exposed themselves to risk. These among-individual differences in foraging behaviour were associated with consistent patterns of resource exploitation. Thus, different strategies in foraging-under-risk ultimately lead to unequal payoffs and might affect lower trophic levels in food webs. Inter-individual differences in foraging behaviour, i.e. foraging personalities, are an integral part of foraging behaviour and need to be fully integrated into optimal foraging theory.

Fluctuations in Density-Dependent Selection Drive the Evolution of a Pace-of-Life Syndrome Within and Between Populations

“…Although empirical and experimental studies are an essential step to test predictions of the density-dependence POLS framework, exploring its utility first by resorting to modelling appears plausible to inform subsequent experiments. Here, we present a spatially explicit agent-based model that integrates two heritable traits: 1) the responsiveness (as reactivity towards environmental cues sensu Wolf et al 2008) to differences in resource extractability (harvest rates) in the landscape as a fundamental behavioral trait, which is testable in empirical studies (Oudman et al 2018;Eccard et al 2020) and relates to multiple behavioral traits associated with the POLS (Wolf et al 2008;Zwolak and Sih 2020), and 2) the reproductive investment threshold as a life-history trait representing capital breeding (Stephens et al 2009).…”

Seed predation and dispersal by small mammals in a landscape of fear: effects of personality, predation risk and land‐use change

“…A majority of the existing literature on landscapes of fear focuses on large mammals, invertebrates or birds (Gaynor et al 2019), and those that focus on small mammals almost exclusively examine giving‐up densities (reviewed by Bleicher 2017). Although very few studies address the role of individual variation in perceived predation risk (Eccard et al 2020, Steinhoff et al 2020), this is a crucial step towards understanding how the spatial variation in perceived predation risk may influence forest ecosystems via the foraging decisions of scatter‐hoarding small mammals.…”

“…In field experiments, Dammhahn and Almeling (2012) examined boldness on risk‐sensitive foraging of grey mouse lemurs Microcebus murinus under high and low predation risk, and Brehm et al (2019) demonstrated that personality affected how free‐living deer mice Peromyscus maniculatus and southern red‐backed voles Myodes gapperi interacted with and dispersed seeds of varying sizes (a proxy for risky behavior). Further, only a few studies address personality and foraging in the landscape of fear; Steinhoff et al (2020) examined how personality affected risk‐taking and foraging behavior of jumping spiders Marpissa muscosa , and Eccard et al (2020) explored how personality affected the response of common voles Microtus arvalis to either a safe or a risky food patch within an enclosure. While the aforementioned studies provide foundational evidence that personality affects the interaction of scatter‐hoarders with seeds, three critical knowledge gaps still exist.…”

Collective action or individual choice: Spontaneity and individuality contribute to decision-making inDrosophila

“…Inter-individual variability may arise either from consistent differences between individuals (i.e., 'individuality' (Beauchamp, 2001;Eccard et al, 2020;Gosling, 2001; Gosling and John, 1999;Hasenjager et al, 2020;Honegger and de Bivort, 2018;Massol and Crochet, 2008;Nettle, 2006;Réale et al, 2007;Sih et al, 2004;Verbeek et al, 1994;Wolf et al, 2007)), and/or by individuals generally behaving inconsistently over time (i.e., 'spontaneity'; (Brembs, 2011;De Felice and Holland, 2018;Lichtenstein et al, 2017;Maye et al, 2007;Morgan and Neuringer, 1990;Jensen, 2013, 2010)). Of course, individuals may also differ consistently in their variability (Hertel et al, 2020).…”