The effects of familiarity on escape responses in the Trinidadian guppy (Poecilia reticulata)

Abstract

Predation is the main cause of mortality during early life stages. The ability to avoid and evade potential threats is, therefore, favoured to evolve during the early stages of life. It is also during these early stages that the process of familiarization occurs. It has long been recognized that associating with familiar individuals confers antipredator benefits. Yet gaps in our knowledge remain about how predator evasion is affected by social experience during early stages. In this study, we test the hypothesis that familiarization acquired during early life stages improves escape responses. Using the guppy Poecilia reticulata, we examine the effect of different recent social conditions in the three main components of predator evasion. Using high-speed motion analysis, we compared the number of individuals in each test group that responded to a visual stimulus, their reactive distance and magnitude of their response (maximum speed, maximum acceleration and distance) in groups composed either of familiar or non-familiar individuals. Contrary to the prediction, groups composed of familiar individuals were less responsive than groups of unfamiliar individuals. Reactive distance and magnitude of response were more dependent on individual size rather than on familiarity. Larger individuals reached higher maximum speeds and total distances in their escape response. Our result indicates that familiarity is likely to affect behaviour earlier in a predator-prey interaction, which then affects the behavioural component of the response. Taken together, our study contributes to previous ones by distinguishing which components of an escape response are modulated by familiarity.

Maternal predator‐exposure affects offspring size at birth but not telomere length in a live‐bearing fish

“…First, females responded to predator models and to the alarm cue by showing the typical antipredator behavior observed in natural conditions and as found in previous laboratory experiments (Evans et al, 2007;Heathcote et al, 2017). Second, we found a significant reduction of offspring size at birth, which suggests that the stress experienced by the mothers during the gestation negatively impacted offspring as a reduced size constrains escape performance (Dial et al, 2016;Wolcott, Ojanguren, & Barbosa, 2017) and survival (Henrich, 1988) in fishes. Our result aligns with previous evidence in fishes in which the exposure to glucocorticoids (such as the cortisol) in the mother, and in turn in their eggs (Hwang, Wu, Lin, & Wu, 1992), was followed by the production of smaller offspring compared with offspring produced by undisturbed mothers (Eriksen et al, 2006;McCormick, 1998).…”

Group composition and its ontogenetic changes in marine pelagic fishes

“…For example, the anti-predator benefits of grouping can be enhanced by associating with individuals of the same phenotype (e.g., colour, size, shape, and sex) to reduce a predator’s capture success rate due to the confusion effect (Krakauer, 1995; Landeau & Terborgh, 1986) and to reduce predation risk via the oddity effect (Landeau & Terborgh, 1986; Ohguchi, 1978; Theodorakis, 1989). In addition, grouping benefits can be enhanced by associating with kin and/or familiar individuals (Hamilton, 1964; Ward & Hart, 2003), for example, by increasing reciprocity and behavioural synchronization within a group (e.g., Davis et al, 2017; Hesse et al, 2015), leading to enhanced predator avoidance and evasion (e.g., Chivers et al, 1995; Nadler et al, 2021; Wisenden & Smith, 1998; Wolcott et al, 2017).…”