Caudal luring
Encyclopedia
Caudal luring is the use of tail
movements employed by a predator to attract prey animals. It is a form of mimicry classified formally as aggressive mimicry
, but perhaps better described by the term feeding mimicry. The behavior is employed by a number of snake species and allegedly by two lizards, though other interpretations (e.g., distraction) seem more plausible for the lizards. Caudal luring also occurs in a shark, the tasselled wobbegong
, Eucrossorinus dasypogon.
The behavior is associated with sedentary predators whose diets include animals susceptible to a worm-like (or fish-like, in the case of Eucrossorinus) luring appendage. Snakes generally lure small ectotherms (e.g., frogs and lizards), although luring of birds has been demonstrated and luring of insectivorous mammals is suspected. Caudal luring occurs most often in juvenile snakes and is most prevalent in vipers and pitvipers, but it also occurs in boas, pythons, tropidophiids, colubrids, and elapids of the genus Acanthophis
.
Caudal luring has been used as an experimental paradigm to investigate stimulus control and visual perception in viperid snakes, and there appears to be much potential for future studies of cognition in both snakes and the animals that they dupe. It has been suggested that caudal luring was involved in the evolution of the rattlesnake
rattle. Attempts have been made to test this intriguing hypothesis, but the evidence is not yet convincing either way. Unfortunately, dubious reports of caudal luring and concomitant speculations have clouded thinking on this subject.
Prey luring in general is a field muddled by false identification. The difficulty is that there are a number of other behavioral interpretations for a wiggling appendage, and luring-like motions are associated with several other behavioral contexts (e.g., defense, stress, etc.). Caudal luring is thought to have evolved from a caudally localized intention movement (a behavior derived from locomotor movements). Essentially, the act of remaining stationary while sensing prey produces general nervous system excitation that gets released in the form of tail movements. Caudal luring is not merely tail undulations, but must specifically be attractive to prey. Caudal distraction is another behavior used by snakes, and the tail motions are very similar to caudal luring. The difference is in the snake's posture and especially in the nature and outcome of the behavior in reference to the encounter with prey. Other caudal luring-like movements occur as warning signals and are induced by stressful circumstances. Thus identifying caudal luring entails observing the effect that tail movements have on prey species, a burden of evidence that is woefully lacking in much of the literature on this intriguing behavior.
Tail
The tail is the section at the rear end of an animal's body; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, reptiles, and birds...
movements employed by a predator to attract prey animals. It is a form of mimicry classified formally as aggressive mimicry
Aggressive mimicry
Aggressive mimicry is a form of mimicry where predators, parasites or parasitoids share similar signals with a harmless model, allowing them to avoid being correctly identified by their prey or host...
, but perhaps better described by the term feeding mimicry. The behavior is employed by a number of snake species and allegedly by two lizards, though other interpretations (e.g., distraction) seem more plausible for the lizards. Caudal luring also occurs in a shark, the tasselled wobbegong
Tasselled wobbegong
The tasselled wobbegong, Eucrossorinus dasypogon, is a carpet shark in the family Orectolobidae, found in the western Pacific Ocean between latitudes 1° N and 23° S. It reaches a length of 1.25 m.Reproduction is ovoviviparous....
, Eucrossorinus dasypogon.
The behavior is associated with sedentary predators whose diets include animals susceptible to a worm-like (or fish-like, in the case of Eucrossorinus) luring appendage. Snakes generally lure small ectotherms (e.g., frogs and lizards), although luring of birds has been demonstrated and luring of insectivorous mammals is suspected. Caudal luring occurs most often in juvenile snakes and is most prevalent in vipers and pitvipers, but it also occurs in boas, pythons, tropidophiids, colubrids, and elapids of the genus Acanthophis
Acanthophis
Acanthophis is a genus of elapid snakes. Commonly called death adders, they are native to Australia, New Guinea and nearby islands, and are among the most venomous snakes in the world...
.
Caudal luring has been used as an experimental paradigm to investigate stimulus control and visual perception in viperid snakes, and there appears to be much potential for future studies of cognition in both snakes and the animals that they dupe. It has been suggested that caudal luring was involved in the evolution of the rattlesnake
Rattlesnake
Rattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae . There are 32 known species of rattlesnake, with between 65-70 subspecies, all native to the Americas, ranging from southern Alberta and southern British Columbia in Canada to Central...
rattle. Attempts have been made to test this intriguing hypothesis, but the evidence is not yet convincing either way. Unfortunately, dubious reports of caudal luring and concomitant speculations have clouded thinking on this subject.
Prey luring in general is a field muddled by false identification. The difficulty is that there are a number of other behavioral interpretations for a wiggling appendage, and luring-like motions are associated with several other behavioral contexts (e.g., defense, stress, etc.). Caudal luring is thought to have evolved from a caudally localized intention movement (a behavior derived from locomotor movements). Essentially, the act of remaining stationary while sensing prey produces general nervous system excitation that gets released in the form of tail movements. Caudal luring is not merely tail undulations, but must specifically be attractive to prey. Caudal distraction is another behavior used by snakes, and the tail motions are very similar to caudal luring. The difference is in the snake's posture and especially in the nature and outcome of the behavior in reference to the encounter with prey. Other caudal luring-like movements occur as warning signals and are induced by stressful circumstances. Thus identifying caudal luring entails observing the effect that tail movements have on prey species, a burden of evidence that is woefully lacking in much of the literature on this intriguing behavior.