Condition explains individual variation in mobbing behavior

Abstract

During mobbing, individuals approach predators with the apparent aim of reducing the risk of predation. The intensity of mobbing may depend on the costs and benefits of this behavior, which likely vary among individuals and between different social contexts. We studied whether Dark‐eyed junco male mobbing behavior is related to social environment, individual condition, and age during experimentally induced mobbing events. Based on risk‐taking theory, we predicted that individuals with high residual reproductive value—younger individuals and those in better condition—would show weaker mobbing behavior. We also expected to see weaker mobbing when the total number of individuals in the mobbing assemblage was small. All subjects were caught to assess condition and age. Focal males were then attracted to simulated mobbing events using heterospecific alarm calls. Social environment did not explain individual variation in mobbing behavior in focal juncos. Community‐wise, the relationship between the closest approach and group size was not significantly different from chance. Junco males in better condition approached the predator less closely and were less likely to give alarm calls. Age did not explain variation in mobbing. Both the mean approach and probability of giving alarm calls by junco males were repeatable, in contrast to the size and composition of mobbing assemblages in junco territories, which were inconsistent. Our results show that variation in mobbing can be linked to individual state, which likely affects the costs and benefits of mobbing.

Proximate predictors of variation in egg rejection behavior by hosts of avian brood parasites.

“…Mass has been associated with egg rejection in interspecific comparisons (Peer & Sealy, 2004), where larger species are more likely to reject parasitic eggs. At an intraspecific level, heavier females may have higher expected future reproductive success (Abolins-Abols & Ketterson, 2017; Blums, Clark, & Mednis, 2002), possibly leading to a reduced sensitivity to parasitic stimuli. More focal experimental work will be needed to assess the mechanisms behind this association.…”

Mobbing-like response to secondary predator cues is not a form of teaching in meerkats

“…However, the principal benefit of mobbing is thought to be predator deterrence, either by intimidating and driving away the predator, or by alerting it that it has been detected and thus reducing the chance of successful attack (Abolins-Abols & Ketterson, 2017;Caro, 2005).…”

Determinants of hyena participation in risky collective action

“…Interestingly, we also found that participation in mobbing was more sensitive to the potential costs of participation than the potential benefits of success, as hyenas were most likely to mob in sessions where risk was relatively low regardless of potential resource benefits. Studies of mobbing in other species similarly indicate that mobbing participants are often the group members with the lowest cost-benefit ratios [ 40 , 73 ].…”

“…We also predicted that hyenas would be more likely to participate when they are in top physical condition (i.e. prime-aged and good nutritional state), such that they can escape from lions more easily and thus bear a lower cost of participation [ 14 , 40 ]. Based on theoretical studies showing the importance of social networks to successful cooperation [ 16 , 17 ], we also predicted that hyenas would be more likely to participate when their social allies or kin are present, as occurs in other socially complex species [ 41 , 42 ].…”