Exposure to predators reduces collective foraging aggressiveness and eliminates its relationship with colony personality composition

Abstract

Predation is a ubiquitous threat that often plays a central role in determining community dynamics. Predators can impact prey species by directly consuming them, or indirectly causing prey to modify their behavior. Direct consumption has classically been the focus of research on predator-prey interactions, but substantial evidence now demonstrates that the indirect effects of predators on prey populations are at least as strong as, if not stronger than, direct consumption. Social animals, particularly those that live in confined colonies, rely on coordinated actions that may be vulnerable to the presence of a predator, thus impacting the society’s productivity and survival. To examine the effect of predators on the behavior of social animal societies, we observed the collective foraging of social spider colonies (Stegodyphus dumicola) when they interact with dangerous predatory ants either directly, indirectly, or both. We found that when colonies were exposed directly and indirectly to ant cues, they attacked prey with approximately 40–50% fewer spiders, and 40–90% slower than colonies that were not exposed to any predator cues. Furthermore, exposure to predatory ants disassociated the well-documented positive relationship between colony behavioral composition (proportion of bold spiders) and foraging aggressiveness (number of attackers) in S. dumicola, which is vital for colony growth. Thus, the indirect effects of predator presence may limit colony success. These results suggest that enemy presence could compromise the organizational attributes of animal societies.

Intraindividual Behavioral Variability Predicts Foraging Outcome in a Beach-dwelling Jumping Spider

“…This suggests that behavioral inconsistency (IIV) can predict outcomes of predator-prey interactions that average behavior (personality) cannot. This suggests that numerous studies probing the role of personality in spider feeding behavior 38 – 40 may not have considered all relevant intraspecific behavioral variation. Notably, neither average activity level nor activity IIV predicted the number of prey that spiders consumed (Table 1 ), meaning that variation in activity level both within and across individuals is seemingly unrelated to prey capture success.…”

Repeatable group differences in the collective behaviour of stickleback shoals across ecological contexts

“…Most studies on collective behaviour have focused on a single biological context [ 30 ], and experimental tests of how the environmental context may result in group-level changes in behaviour have been limited (e.g. [ 35 , 36 ]). Whether animal groups exhibit repeatable behavioural differences across ecological contexts thus remains an open question.…”

Individual Thigmotactic Preference Affects the Fleeing Behavior of the American Cockroach (Blattodea: Blattidae)

“…For example, the fission–fusion dynamics of groups of bats ( Kerth 2010 ) and birds ( Aplin et al 2013 ) is influenced by the personality of each individual; the aggregation dynamics of Periplaneta americana (Linnaeus, 1758) (Blattodea: Blattidae) is influenced by individual and group personalities ( Planas-Sitjà et al 2015 ); and individual personality in stickleback fish strongly affected the group’s structure, movement dynamics, and foraging behavior ( Jolles et al 2017 ). Regarding fleeing behavior, different studies have found the existence of behavioral syndromes ( Carter et al 2010 , Niemelä et al 2012 , Seltmann et al 2012 , Cooper Jr and Blumstein 2015 ) and that some events, like an increase of risk or stress, might break apart individual personalities ( Niemelä et al 2012 , Cote et al 2013 , Wright et al 2017 ).…”