User:Aennis15/Caudal luring

A baby coastal carpet python, Morelia spilota mcdowelli, demonstrating use of its tail as a lure for prey.

Caudal luring is a form of aggressive mimicry in which a predator uses tail movements to attract prey animals. The prey animal misinterprets the tail as a worm-like species or another smaller prey. Once the prey animal is within striking range, the predator attacks. Snakes, more often juvenile snakes, and some types of shark are the main species that practice caudal luring.

The mimicry was initially interpreted as a warning sign which the species displayed under stressful circumstances. The study of the tail movements suggested that the caudal luring behavior evolved from tail vibration. Researchers have also used different experiential paradigm for caudal luring to investigate stimulus control and visual deception in snakes.

Mimicry

The tail of a species may serve various functions, such as aggression, defense and feeding.  The caudal luring behavior was first recorded in 1878 and is a form of mimicry known as aggressive mimicry.  Predators attract their prey by moving their caudal section in a way that mimics the victim’s potential prey. The predator’s potential prey is intrigued by caudal behavior and will investigate assuming it is their own prey. Once the potential prey is in avulnerable position, the predator has an opportunity to strike and consume the lured prey.

Species

Snakes

The caudal luring behavior is observed in over 50 different snake species. It is most common in boas, pythons, thropidopiids, colubrids and elapids of the genus Acanthosis. It is, however, the most obvious in vipers and pit vipers, which are better known as rattlesnakes. As the snake is waiting for its prey, it is coiled up and has its distinctively marked tail elevated, visible and moving in a way that captures the attention of its prey. Once the prey is in striking range, the snake captures the prey. Due to the tail resembling a writhing caterpillar and another worm-like insect larvae, the tail of the snake is often referred to as a vermiform. Snakes usually prey on small ectotherms such as frogs and lizards.

Juvenile Snakes

Caudal luring is more frequently observed in juvenile snakes. Of the snakes that practice the caudal luring behavior, 80% of the snakes are juvenile. The tails of juvenile snakes are often a vibrant color, making them difficult to ignore. As the juvenile snakes mature into adulthood, their tail color will become consistent with the rest of their body.

Juvenile snakes have a smaller lure compared to the size of an adult's lure. Studies show that a smaller lure is more effective in attracting prey, as it is closer to the size of the worm-like prey. This may explain why caudal luring is more often seen and successful in younger snakes.

Sharks

Caudal luring is also observed in some species of sharks. It is common among three shark species: Alopias valpinue, Alopias superciliosus and Alopias pelagicus Nakamura. Even though they have many structural differences, it has been proposed that the three alopiids species use their elongated dorsal lobe of the caudal fin to lure the prey before it is eaten. Similarly to snakes, the operational role of the shark's caudal fin is to both seek and immobilize the prey so they can attack and feed themselves. More research is needed with the caudal luring behavior in sharks

Caudal luring behavior also is noticed in tasselled wobbegong (Eucrossorhinus dasypogon) which is a species of carpet shark .Its caudal fin resembles a small fish with a small dark spot that resembles an eye . When the tasselled wobbegong targets its prey, it waves, its caudal fin slowly to attract prey, similar to other caudal luring species, and then captures them.

Other

Caudal luring behavior is highly likely in some eel species, more specifically pelican eels.

Research

Experimental Paradigm

There is an incomplete understanding of the cognitive dynamics of caudal luring in snakes. This is because most studies are not hypothesis-based and include a small number of subjects. Experimental paradigms with multiple subjects for caudal luring have been used to investigate theses cognitive dynamics, such as stimulus control and visual perception in viperid snakes.

Evolution

It has been suggested that caudal luring was involved in the evolution of the tail vibration rattle of rattlesnakes, a warning signal and a way of auditory communication. Attempts have been made to test this hypothesis; however the evidence is controversial. There have been questionable accounts of caudal luring and concomitant speculations.

Interpretation

Prey luring, in general, is confounded by false interpretation. The difficulty is that there are several other behavioral interpretations for a wiggling appendage, and luring-like motions are associated with several other behavioral contexts. Other functions of caudal luring can be related to aposematic and a defensive mechanism, or it can also be a nervous release.

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, something that has rarely been achieved.