A lure at both ends: aggressive visual mimicry signals and prey-specific luring behaviour in an ambush-foraging snake

Abstract

Aggressive mimic species use signals typically resembling an attractive or harmless model to deceive other organisms in order to increase foraging success. With the exception of a few brood parasitic birds that combine two signals, most known cases of aggressive mimicry involve only a single signal. Here, we used fixed videography, a technique which consisted in setting up continuously recording videocameras focused on ambushing animals, to describe—for the first time—the use of two clearly distinct aggressive visual mimicry signals in the same organism, the puff adder (Bitis arietans). Our observational data collected in South Africa revealed that puff adders extended their tongues (lingual luring) and waived their tails (caudal luring), presumably mimicking an invertebrate model, in order to lure prey within striking range. Lingual luring occurred only in the presence of amphibian prey, indicating discrimination between prey types. Our study reveals the diverse predatory strategies and complex decision-making process used by ‘sit-and-wait’ predators, such as ambush-foraging snakes, to catch prey, and indicates that snakes may have higher cognitive abilities than those usually afforded to them. Predators exhibit various strategies to increase rates of prey capture. One strategy involves the use of luring behaviours, which are signals designed to attract prey within striking range. Using remote videocameras focused on ambush-hunting puff adders (Bitis arietans) in the field, we report—for the first time—the use of two clearly distinct luring behaviours in the same organism: puff adders extended their tongues and waived their tails, which presumably resemble invertebrate prey, to draw prey within striking range. Tongue-luring behaviour was solely used in the presence of amphibian prey, which indicates that puff adders distinguished between prey types. Our research underscores that the predatory decisions made by ambush-foraging snakes are diverse and context-dependent and further demonstrates that these predators possess higher cognitive abilities than first expected.