High-predation habitats affect the social dynamics of collective exploration in a shoaling fish

Ioannou, Christos C.; Ramnarine, Indar W.; Torney, Colin J.

doi:10.1126/sciadv.1602682

Cited by 76 publications

(69 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ing group are most at risk from predation (11)(12)(13)(14)(15)(16). This provides the missing empirical evidence for this central expectation that was limited to potentially confounded observations within a single prey and predator species pair (17,18).…”

Section: Discussionmentioning

confidence: 98%

“…While there are clear benefits to leading, this strategy is widely assumed to be inherently riskier than following, presumably because the front of moving groups could encounter predators first or because individuals in lead positions are easier to target. This spatial pattern of predation risk within groups has been assumed to apply to groups of animals as diverse as monkeys (11), meerkats (12), coatis (13), muskoxen (14), starlings (15), and guppies (16). However, despite the importance of this assumption for our understanding of the diversity of social strategies, no experimental (i.e., manipulative) tests have been performed to identify whether the risk of leadership can be sep-arated from other confounding factors.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Predators attacking virtual prey reveal the costs and benefits of leadership

Ioannou

Rocque²,

Herbert‐Read

et al. 2019

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

A long-standing assumption in social behavior is that leadership incurs costs as well as benefits, and this tradeoff can result in diversified social roles in groups. The major cost of leadership in moving animal groups is assumed to be predation, with individuals leading from the front of groups being targeted more often by predators. Nevertheless, empirical evidence for this is limited, and experimental tests are entirely lacking. To avoid confounding effects associated with observational studies, we presented a simulation of virtual prey to real fish predators to directly assess the predation cost of leadership. Prey leading others are at greater risk than those in the middle of groups, confirming that any benefits of leading may be offset by predation costs. Importantly, however, followers confer a net safety benefit to leaders, as prey leading others were less likely to be attacked compared with solitary prey. We also find that the predators preferentially attacked when solitary individuals were more frequent, but this effect was relatively weak compared with the preference for attacking solitary prey during an attack. Using virtual prey, where the appearance and behavior of the prey can be manipulated and controlled exactly, we reveal a hierarchy of risk from solitary to leading to following social strategies. Our results suggest that goal-orientated individuals (i.e., potential leaders) are under selective pressure to maintain group cohesion, favoring effective leadership rather than group fragmentation. Our results have significant implications for understanding the evolution and maintenance of different social roles in groups.

show abstract

Section: Discussionmentioning

confidence: 98%

mentioning

confidence: 99%

Predators attacking virtual prey reveal the costs and benefits of leadership

Ioannou

Rocque²,

Herbert‐Read

et al. 2019

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…A heavier brain may also allow individual guppies to better address social demands, such as group cohesion or coordination with conspecifics (Dunbar & Shultz, ). Guppies from high‐predation populations do form more cohesive and coordinated groups (Ioannou, Ramnarine, & Torney, ), and group cohesion has antipredator benefits in prey fishes (Ioannou, Guttal, & Couzin, ; Krause & Ruxton, ). Interestingly, predation seems to select for a reduction in brain size in some other fish species, and the putative advantages of increased brain size in the face of predation risk thus certainly merit closer examination (Samuk et al., ; Walsh et al., ).…”

Section: Discussionmentioning

confidence: 99%

“…A heavier brain may also allow individual guppies to better address social demands, such as group cohesion or coordination with conspecifics (Dunbar & Shultz, 2017). Guppies from high-predation populations do form more cohesive and coordinated groups (Ioannou, Ramnarine, & Torney, 2017), and group cohesion has antipredator benefits in prey fishes (Ioannou, Guttal, & Couzin, 2012;Krause & Ruxton, TA B L E 4 Estimates and standard error of fixed parameters and their interaction for the linear model with log-transformed brain mass for the guppy laboratory developmental study. Estimates represent the difference in log-transformed brain mass between the level of a factor (identified in parenthesis) and the reference level for the categorical factor (the predator cue treatment) and are mean-centred for covariates.…”

Section: Discussionmentioning

confidence: 99%

Wild and laboratory exposure to cues of predation risk increases relative brain mass in male guppies

et al. 2018

View full text Add to dashboard Cite

There is considerable diversity in brain size within and among species, and substantial dispute over the causes, consequences and importance of this variation. Comparative and developmental studies are essential in addressing this controversy. Predation pressure has been proposed as a major force shaping brain, behaviour and life history. The Trinidadian guppy, Poecilia reticulata, shows dramatic variation in predation pressure across populations. We compared the brain mass of guppies from high and low predation populations collected in the wild. Male but not female guppies exposed to high predation possessed heavier brains for their body size compared to fish from low predation populations. The brain is a plastic organ, so it is possible that the population differences we observed were partly due to developmental responses rather than evolved differences. In a follow‐up study, we raised guppies under cues of predation risk or in a control condition. Male guppies exposed to predator cues early in life had heavier brains relative to their body size than control males, while females showed no significant effect of treatment. Collectively our results suggest that male guppies exposed to predation invest more in neural tissue, and that these differences are at least partly driven by plastic responses. A http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.13128/suppinfo is available for this article.

show abstract

“…There is a relationship between shoal size and trophic level. Fish that use more available resources often form bigger shoals, which can influence vigilance time reflecting on FID Rieucau, Fernö, Ioannou, and Handegard (2015) Habitat use Goldenberg, Borcherding, and Heynen (2014); Ioannou, Ramnarine, and Torney (2017) We controlled for non-independence of effect sizes within studies by including "study identity" as a random factor in the body size-FID model (Appendix 3). Data could exhibit non-independence caused either by phylogenetic inertia or by multiple estimates per species, and the model selection showed that inclusion of "phylogeny" and/ or "species identity" as additional random effects did not improve the model (Appendix 3).…”

Section: Species' Body Sizementioning

confidence: 99%

A meta‐analysis of fish behavioural reaction to underwater human presence

et al. 2019

View full text Add to dashboard Cite

In an increasingly anthropic world, humans have profound impacts on the distribution and behaviour of marine fishes. The increased human presence has modified fishes’ antipredator behavioural responses, and consequently flight decisions, as a function of their changed perceptions of risk. Understanding how fish react to human presence can help identify the most vulnerable functional groups/species and estimate impacts caused by human disturbance. Shoal and body size are known to influence fish flight initiation distance (FID; the distance between the predator and prey when the prey begins to escape); however, few studies attempt to test the moderators of these relationships. Here, we present a comprehensive meta‐analysis evaluating FID of fish in response to human presence. Specifically, we investigated six candidate moderators that could influence the relationship between FID with shoal and body size. Our results showed that individual fish size was strongly and positively correlated with FID and the most important moderator that explained the variance in individual body size‐FID relationship was shoaling behaviour. However, and somehow surprisingly, we detected no significant relationship between shoal size and FID. We discuss how these results can inform the development of fish conservation strategies and ultimately assist in the management of marine protected areas.

show abstract

High-predation habitats affect the social dynamics of collective exploration in a shoaling fish

Abstract: Comparing across populations, we show that predation has multiple effects on collective exploration in groups of guppies.

Cited by 76 publications

References 61 publications

Predators attacking virtual prey reveal the costs and benefits of leadership

Predators attacking virtual prey reveal the costs and benefits of leadership

Wild and laboratory exposure to cues of predation risk increases relative brain mass in male guppies

A meta‐analysis of fish behavioural reaction to underwater human presence

Contact Info

Product

Resources

About