Eyes predator vs prey4/18/2024 ![]() ![]() Alternatively, concentric circles with either a bright or dark central region, and the opposite value in its surround may be particularly effective at stimulating vertebrate visual systems and associated brain regions (e.g., the optic tectum Mey and Thanos, 2000). ![]() This may well be due to the radial development of pigmented cells from each eyespot’s center ( Monteiro, 2015). However, many (although by no means all) eyespots consist of multiple concentric rings of contrasting colors ( Skelhorn et al., 2016). There are lots of ways to be conspicuous and several ways to resemble eyes. The specific design of eyespots has received much less attention (though see: Stevens et al., 2008 Blut et al., 2012 Hossie et al., 2015 Kjernsmo and Merilaita, 2017 and related papers on responses of birds and reptiles to eye-like stimuli, e.g., Gagliardi et al., 1976 Hennig, 1977). Eyespots appear to exploit predators’ innate or learned aversions to conspicuously colored prey ( Stevens et al., 2008, 2009), and mimic the eyes of the predators’ own predators ( Blut et al., 2012 De Bona et al., 2015 Kjernsmo and Merilaita, 2017). However, there is now evidence for two non-exclusive explanations. The question of why predators should find eyespots aversive has caused considerable debate ( Stevens, 2005 Stevens and Ruxton, 2014 Mukherjee and Kodandaramaiah, 2015). Larger eyespots such as those of the peacock butterfly Aglais io elicit an aversive response in predators ( Vallin et al., 2005, 2010, 2011 Kodandaramaiah et al., 2009). The eyespots are thought to draw predators’ attention, causing them to direct their attacks toward dispensable areas (e.g., wing margins), enhancing the chances that prey will survive the attack ( Blest, 1957 Kjernsmo and Merilaita, 2013 Prudic et al., 2015). Peripherally positioned eyespots, such as those of the squinting bush brown ( Bicyclus anynana) and the woodland brown ( Lopinga achine) butterflies, can deflect attacks to non-vital body parts ( Olofsson et al., 2010 Skelhorn et al., 2014). They are among the most studied wing color pattern elements in lepidoptera ( Stevens, 2005 Kodandaramaiah, 2011), and their antipredator benefits have been predicted or established in various taxa ( Stevens, 2005) including Lepidoptera ( Lyytinen et al., 2004 Vallin et al., 2005, 2011 Wiklund, 2005 Olofsson et al., 2010, 2012 Merilaita et al., 2011 Ho et al., 2016 Halali et al., 2019 Chan et al., 2021), Orthoptera ( Steiner, 1981 Castner, 1995), Coleoptera ( Buschman, 1988), and fishes ( Altbäcker and Csányi, 1990 Meadows, 1993 Gagliano, 2008 Kjernsmo and Merilaita, 2013 Kjernsmo et al., 2016 Hemingson et al., 2021).Įyespots reduce the chance of being eaten in a number of ways. Whilst in some species eyespots appear to play a role in mate choice ( Robertson and Monteiro, 2005 Huq et al., 2019), one of their key functions is to protect prey from predators ( Blest, 1957 Stevens, 2005 Kjernsmo and Merilaita, 2013 Prudic et al., 2015). These are known as eyespots and are conspicuous circular or quasi-circular markings ( Mukherjee and Kodandaramaiah, 2015). Many prey species possess markings that subjectively appear to resemble vertebrate eyes ( Janzen et al., 2010). They are also consistent with the idea that eyespots are mistaken for eyes, and are perceived to pose a lesser risk when their “gaze” is averted from the approaching predator. These findings suggest that eyespots composed of concentric circles may protect prey against predators approaching from a wider range of directions than eyespots composed of eccentric circles. Chicks that approached from either the left or the right, were slower to attack prey in which the central circle of the eyespot was centrally placed or shifted in the direction of the chick’s approach, compared to prey in which the central circle had been shifted away from the direction of approach. We found that when chicks approached prey straight on, eyespots configuration did not influence attack latency. ![]() Here we used naïve domestic chicks as predators of artificial moth-like prey to test the hypothesis that both eyespots configuration and predator approach direction affect the antipredator efficacy of eyespots. Predators are wary of such prey because eyespots are conspicuous and/or mistaken for vertebrate eyes. Many prey species possess eyespots: paired markings that often consist of two or more concentric circles.
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