Although numerous studies about camouflage have been conducted in the last few decades, there is still a significant gap in our knowledge about the magnitude of protective value of different camouflage strategies in prey detection and survival. Furthermore, the functional significance of several camouflage strategies remains controversial. Here we carried out a comprehensive meta-analysis including comparisons of different camouflage strategies as well as predator and prey types, considering two response variables: mean predator search time (ST) (63 studies) and predator attack rate (AR) of camouflaged prey (28 studies). Overall, camouflage increased the predator ST by 62.56% and decreased the AR of prey by 27.34%. Masquerade was the camouflage strategy that most increased predator ST (295.43%). Background matching and disruptive coloration did not differ from each other. Motion camouflage did not increase ST but decreases AR on prey. We found no evidence that eyespot increases ST and decreases AR by predators. The different types of predators did not differ from each other, but caterpillars were the type of prey that most influenced the magnitude of camouflage's effect. We highlight the potential evolutionary mechanisms that led camouflage to be a highly effective anti-predatory adaptation, as well as potential discrepancies or redundancies among strategies, predator and prey types.

The visual properties of the background occupied by organisms are a key aspect of visual camouflage. Changes in background coloration by fires may mediate the differential survival of prey against visually oriented predators and modify the prey camouflage strategy. This phenomenon may be common in environments where the fire is a continuous modulator of the community, such as Neotropical savannas. In this study, we investigated whether arthropods match burned and unburned trunks in coloration in order to camouflage relative to the visual system of potential bird predators. We also investigated in which type of the trunk the black and brown morphotypes of Ronderosia bergii (Orthoptera) preferentially occupy and whether the morphotypes present colour matching in the burned and unburned trunks. We recorded the arthropod community on backgrounds against which they had low contrast relative to other available backgrounds. We found that specimens of R. bergii preferentially occupy burned backgrounds. In addition, we also found that black morphotypes of R. bergii showed lower contrasts on burned trunks to the achromatic channel, while browner morphotypes showed lower contrasts on unburned backgrounds in the chromatic channel. We propose three explanations operating behind the observed pattern of the studied community: differential predation; background selection; and animal colour change.

Predation is one of the most important ecological factors determining the structure and functioning of ecosystems. Among the various strategies used by predators to obtain food, there are those in which they take advantage of the vulnerability of the prey during its foraging bouts. An unexplored example of this strategy is the interaction between vertebrate pollinators and ambush predators. Despite the reports of arboreal tarantulas preying on hummingbirds, little is known about the behaviour of these birds in the presence of their predators. Thus, our study sought to investigate hummingbird behaviour against potential opportunist predators during their search for food resources. We used Heliconia velloziana as a mutualist model, in which, we separated plant flowers in two groups – plants with predators and plants without predators – in order to observe the behaviour of pollinators during their foraging activity. The rate of visitation was also indirectly estimated based on residual nectar and pollen. Our results show that hummingbirds initially avoided contact with the predator, but later they visited both groups indiscriminately. The results suggest that these birds do not have counter‐adaptations to identify invertebrate ambush predators as a threat. Since such predators are generalists and the events of predation are sporadic, they do not exert selective pressures strong enough to lead to the development of evasive behaviours. We conclude that hummingbirds are potential prey for opportunistic ambush predators.