Foraging personalities modify effects of habitat fragmentation on biodiversity

Abstract

Habitat loss undeniably poses a substantial threat to biodiversity, but whether fragmentation per se drives the loss of species is still widely debated. While negative consequences from fragmentation are often anticipated, many empirical studies report positive effects. However, the intrinsic mechanisms governing species' persistence in fragmented landscapes are not yet understood. In this study we investigated consistent personality-dependent differences in foraging behavior among individuals as a possible mechanism underlying the discrepancy of reported fragmentation effects. We devised a mechanistic individual-based model simulating the home range behavior of a competitive small mammal community based on the availability of a shared resource. Thereby, an individual's risk-taking behavior dictates its foraging decisions at risky habitat edges, an inherent property of fragmentation per se. Our simulations show that differences in risktaking while foraging are potentially a further mechanism contributing to reconcile the fragmentation debate. The first scenario considering risk-seeking communities showed a neutral response towards fragmentation, while the second scenario featuring riskavoiding communities confirmed the negative effects of fragmentation. Notably, the third scenario, simulating behaviorally diverse communities including risk-avoiding and risk-seeking individuals, demonstrated a positive influence of fragmentation on biodiversity. Intraspecific differences in behavior could also enhance the temporal species coexistence (coviability) of communities threatened by an ongoing habitat loss. Our study highlights the importance of recognizing the behavioral composition of populations and communities for estimat®ing fragmentation effects, because differences in risk-taking can influence the coping abilities of animal communities in light of fragmentation.

Small‐scale heterogeneity shapes grassland diversity in low‐to‐intermediate resource environments

“…While increasing heterogeneity increases the potential number of species that may exist in a given area (as predicted by the niche theory), the simultaneous reduction in the amount of suitable area available for each species increases the likelihood of stochastic extinction (Kadmon & Allouche, 2007). Interestingly, these contrasting mechanisms are also found in the ongoing discussion on whether landscape fragmentation per se (i.e., the spatial pattern of habitat configuration independent of habitat amount) has positive, negative, or neutral effects on species diversity (Fahrig, 2003, 2017; Fletcher et al, 2018; Rohwäder & Jeltsch, 2022). While these mechanisms are typically related to the landscape scale, a more overarching perspective emerges when two distinct components of environmental heterogeneity are explicitly distinguished: the compositional and configurational heterogeneity (Palmer, 1992; Fahrig et al, 2011; Ben‐Hur & Kadmon, 2020).…”

Multi‐scale effects of habitat loss and the role of trait evolution

“…For example, genetic and phenotypic diversity tend to reduce the vulnerability of populations to environmental change (reviewed in Forsman & Wennersten, 2016), and diversity in individual behavioural traits (risk taking vs. avoiding) can promote species coexistence in communities experiencing HL (Rohwäder & Jeltsch, 2022).…”

“…Conversely, trait variation can play a role in mitigating the population‐dynamic consequences of HL and environmental change. For example, genetic and phenotypic diversity tend to reduce the vulnerability of populations to environmental change (reviewed in Forsman & Wennersten, 2016), and diversity in individual behavioural traits (risk taking vs. avoiding) can promote species coexistence in communities experiencing HL (Rohwäder & Jeltsch, 2022). Furthermore, when the trait variation is heritable, it can also help mitigate the effects of environmental change through ‘evolutionary rescue’ (Bell & Gonzalez, 2011; Boeye et al., 2013; Gonzalez et al., 2013), or conversely aggravate the negative effects through ‘evolutionary trapping’ (Ferriere & Legendre, 2013).…”

Multi-scale Effects of Habitat Loss and the Role of Trait Variation

“…Conversely, trait variation can play a role in mitigating the population dynamic consequences of HL and environmental change. For example, genetic and phenotypic diversity tend to reduce the vulnerability of populations to environmental change (reviewed in Forsman & Wennersten, 2016), and diversity in individual behavioural traits (risk taking vs avoiding) can promote coexistence in communities experiencing HL (Rohwäder & Jeltsch, 2022). Furthermore, when the trait variation is heritable, it can also help mitigate the effects of environmental change through "evolutionary rescue" (Bell & Gonzalez, 2011;Boeye et al, 2013;Gonzalez et al, 2013), or conversely aggravate the negative effects through "evolutionary trapping" (Ferriere & Legendre, 2013).…”