An ambusher's arsenal: chemical crypsis in the puff adder (Bitis arietans)

Abstract

Ambush foragers use a hunting strategy that places them at risk of predation by both visual and olfaction-oriented predators. Resulting selective pressures have driven the evolution of impressive visual crypsis in many ambushing species, and may have led to the development of chemical crypsis. However, unlike for visual crypsis, few studies have attempted to demonstrate chemical crypsis. Field observations of puff adders (Bitis arietans) going undetected by several scent-orientated predator and prey species led us to investigate chemical crypsis in this ambushing species. We trained dogs (Canis familiaris) and meerkats (Suricata suricatta) to test whether a canid and a herpestid predator could detect B. arietans using olfaction. We also tested for chemical crypsis in five species of active foraging snakes, predicted to be easily detectable. Dogs and meerkats unambiguously indicated active foraging species, but failed to correctly indicate puff adder, confirming that B. arietans employs chemical crypsis. This is the first demonstration of chemical crypsis anti-predatory behaviour, though the phenomenon may be widespread among ambushers, especially those that experience high mortality rates owing to predation. Our study provides additional evidence for the existence of an ongoing chemically mediated arms race between predator and prey species.

Naive tadpoles do not recognize recent invasive predatory fishes as dangerous

“…Also, siluriform fishes may have evolved stealth adaptations for inactivating prey‐borne cues during digestion (Feminella and Hawkins , Chivers and Smith , Miller et al. ), hence the inability of tadpoles to sense that conspecifics had been consumed and digested by siluriform predators. These are merely speculations and the lack of behavioral responses to siluriform predators requires further investigation.…”

“…Consequently, concentrations of capture-released, prey-borne cues may be higher in the presence of feeding perciform predators than in that of siluriform fishes, hence the stronger response to the former (sensu Ferrari et al 2007). Also, siluriform fishes may have evolved stealth adaptations for inactivating prey-borne cues during digestion (Feminella and Hawkins 1994, Chivers and Smith 1998, Miller et al 2016, hence the inability of tadpoles to sense that conspecifics had been consumed and digested by siluriform predators. These are merely speculations and the lack of behavioral responses to siluriform predators requires further investigation.…”

Foraging mode, relative prey size and diet breadth: A phylogenetically explicit analysis of snake feeding ecology

“…A corollary of this prediction is that—if ambush foragers are truly more opportunistic predators compared to active foragers—they should also feed on a wider range of prey types. Second, ambush foragers rely more on stealth than speed to catch prey and avoid predators (Miller, Maritz, McKay, Glaudas, & Alexander, ), releasing them from the constraints of a sleek body shape. This has allowed for the evolution of squat bodies and broad heads, which facilitate the ingestion of large meals.…”

The Snake with the Scorpion’s Sting: Novel Three-Finger Toxin Sodium Channel Activators from the Venom of the Long-Glanded Blue Coral Snake (Calliophis bivirgatus)

“…Considerations of the venom delivery system must also include the morphological features associated with prey contact. Ambush feeding snakes such as most viperids rely on camouflage, which itself may be both morphological (pattern) and chemical (control of smell emission) [64]. They typically have muscular builds that facilitate fast and powerful strikes capable of driving their large, flexible fangs deep into a prey item and delivering copious amounts of venom from their bulky venom glands.…”