Camouflage in predators

Abstract

Camouflage – adaptations that prevent detection and/or recognition – is a key example of evolution by natural selection, making it a primary focus in evolutionary ecology and animal behaviour. Most work has focused on camouflage as an anti‐predator adaptation. However, predators also display specific colours, patterns and behaviours that reduce visual detection or recognition to facilitate predation. To date, very little attention has been given to predatory camouflage strategies. Although many of the same principles of camouflage studied in prey translate to predators, differences between the two groups (in motility, relative size, and control over the time and place of predation attempts) may alter selection pressures for certain visual and behavioural traits. This makes many predatory camouflage techniques unique and rarely documented. Recently, new technologies have emerged that provide a greater opportunity to carry out research on natural predator–prey interactions. Here we review work on the camouflage strategies used by pursuit and ambush predators to evade detection and recognition by prey, as well as looking at how work on prey camouflage can be applied to predators in order to understand how and why specific predatory camouflage strategies may have evolved. We highlight that a shift is needed in camouflage research focus, as this field has comparatively neglected camouflage in predators, and offer suggestions for future work that would help to improve our understanding of camouflage.

Towards an ecology of protective coloration

“…Many of the mechanisms that were proposed in the late 19th century by pioneers of the study of animal coloration have been validated in the last 25 years with studies providing 'proof of concept' (see Stevens & Merilaita, 2011;Cuthill et al, 2017;Quicke, 2017). Yet missing from this appreciation of the diversity of defence strategies involving coloration is a comprehensive understanding of the ecological, life-history and behavioural factors that promote the evolution of different forms of protective coloration (Ruxton et al, 2018) although progress is being made (Stevens & Ruxton, 2019;Pembury-Smith & Ruxton, 2020). We have only a weak understanding of why certain species or individuals have evolved, say, crypsis rather than aposematism or mimicry, or use deflective markings while others do not.…”

Habitat determines convergent evolution of cephalic horns in vipers

“…Ambush predators are known for using cryptic phenotypes to avoid detection, ensuring that prey move within striking distance to improve hunting success (Pembury Smith & Ruxton, 2020). Like vipers, the few snake lineages with cephalic appendages also employ ambush foraging.…”

“…Yet, there may be scenarios where disruption or deception by secondary appendages could reduce detection and increase fitness. For example, over evolutionary time predator or prey could adapt to the camouflage strategies of the other and thereby drive the evolution of improved crypsis (Pembury Smith & Ruxton, 2020). Crypsis can also evolve to enhance diurnal concealment or to the differential visual systems of specific organisms (Hughes et al ., 2019; Caro & Koneru, 2021).…”

Colour pattern variation forms local background matching camouflage in a leaf‐mimicking toad

“…margaritifera is highly toxic (Sinhorin et al, 2020), the toads do appear to be at risk from predators including birds, snakes and mammals (Gompper, 1996; Kollarits et al, 2013; McElroy, 2016; Oliveira et al, 2017; Toledo et al, 2007). Indeed, as the toads’ diet primarily consists of invertebrates, a large proportion of which are ants, it seems unlikely that high‐fidelity camouflage would evolve to aid in prey capture although the same principles of camouflage evolution would still apply (Almeida et al, 2019; Pembury Smith & Ruxton, 2020).…”