Fear of predation shapes social network structure and the acquisition of foraging information in guppy shoals

Abstract

Spatio-temporal variation in predation risk is predicted to select for plastic anti-predator responses, which may in turn impact the fine-scale social structure of prey groups and processes mediated by that structure. To test these predictions, we manipulated the ambient predation risk experienced by Trinidadian guppy () groups before quantifying their social networks and recording individual latencies to approach and solve a novel foraging task. High-risk conditions drove the formation of social networks that were more strongly assorted by body size than those exposed to low ambient risk and promoted longer durations of contact between preferred partners. Additionally, high background predation risk reduced the probability individuals would approach and solve a novel foraging task. Network-based diffusion analysis revealed that while social transmission of the task solution from knowledgeable to naive individuals occurred at a higher rate within low-risk groups, individuals in high-risk groups were particularly likely to investigate the task while shoaling with preferred social partners. Taken together, our results suggest that the structure and functional importance of prey social networks may partly depend on local predation pressure. Furthermore, by influencing individuals' access to information, fear of predation may impact decision-making in a potentially wide array of behavioural contexts.

Network-based diffusion analysis reveals context-specific dominance of dance communication in foraging honeybees

“…NBDA estimates the social transmission rate, s, as the rate at which an individual acquires information per unit of network connection with informed individuals, relative to the rate of asocial learning 22,23 . In other words, s quantifies the extent to which observing or interacting with knowledgeable individuals accelerates learning-e.g., of a novel behavioural pattern 25,26,28 or foraging patch location 27,29 -beyond what is expected through individual exploration. Here, social transmission rates were estimated relative to the baseline feeder discovery rate for the average individual in trial 1.…”

“…Following dances is crucial for recruitment to novel sites. Across four trials, each conducted on a separate colony (Table 1), 190 marked bees were trained to one of two identical feeders (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) foragers per feeder per trial; colonies tested sequentially; Fig. 1).…”

“…To overcome this difficulty, we use network-based diffusion analysis (NBDA) 22,23 to tease apart the relative importance of dance-based communication networks, in relation to individual search and olfactory information transfer, in guiding honeybees to both novel and known foraging sites. NBDA has enabled indepth study of social transmission processes across a range of vertebrate taxa [24][25][26][27][28][29] . Its core assumption is that if a learnt behaviour or piece of information-such as discovery of a novel foraging site-spreads via social transmission, then its diffusion will follow a social network 30 .…”

Intraspecific variation in inhibitory motor control in guppies, Poecilia reticulata

“…Trinidadian guppies vary drastically in morphology, life history and behavioural traits due to variation in selection pressures such as predation levels (Devigili et al ., 2019; Endler, 1980; Handelsman et al ., 2013; Hasenjager & Dugatkin, 2017; Herbert‐Read et al ., 2017; Reznick, 1982), water turbidity (Borner et al ., 2015) or ambient light (Endler, 1991, 1993; Gamble et al ., 2003). Recently predation has also been linked to brain evolution in guppies (Kotrschal et al ., 2017; Mitchell et al ., 2020; Reddon et al ., 2018) and killifish ( Rivulus hartii ) (Walsh et al ., 2016) albeit showing contrasting effects for brain size or brain anatomy.…”

Females facilitate male food patch discovery in a wild fish population

“…Here, we performed a unique manipulation of the social environment using individually colour‐marked wild guppies, Poecilia reticulata , living in the rainforest streams of Trinidad. Guppies are a well‐established model to study the mechanisms underlying social foraging (Reader & Laland ; Day, MacDonald, Brown, Laland, & Reader, ; Swaney, Kendal, Capon, Brown, & Laland, 2001; Morrell et al ; Dyer, Croft, Morrell, & Krause, ; Hasenjager & Dugatkin, ). Wild guppies live in a fission–fusion society with adult sex ratios fluctuating heavily in time (i.e.…”