Why copy? the evolution of mimicry  (Page 4/7)

Caudal luring

One of the types of mimicry that is increasingly being studied within the past two decades is caudal luring. This is a form of aggressive mimicry where an individual uses its tail to mimic the shape and movements of a species eaten by their prey, most often worms or insect larvae, in order to attract a meal. This is done by the strategically moving its tail back and forth in a specific way meant to look like the mimicked species, often with their body hidden. Caudal luring is most well known among pit-vipers but has also been shown to happen in pythons and boas (Murphy, Carpenter,&Gillingham 1978) and colubrids (Tiebout 1997 and Barun, Perry, Henderson,&Powell 2007). In his paper, Tiebout explains that the occurrence of caudal luring in colubrid snakes that share ranges with rattlesnakes opposes the hypothesis that rattle snake rattles evolved from small nubs on snake tails used in caudal luring. He states that given this evidence, the other hypothesis for rattles: that they evolved from a hard tail nub used to rub against grass and leaves to ward off danger, is much more likely. A few interesting studies on the subject have shown that younger snakes are much more likely to caudal lure than adults (Rabatsky&Farrell 1996b and Rabatsky&Waterman 2005). However, the reasons for this are still somewhat unclear. It has been suggested that the type of prey has a significance caudal luring, where younger snakes generally eat lizards, frogs, and large insects that would likely prey on worms and larvae, but it was shown that pygmy rattlesnakes, Sistrurus miliarius , which still eat these prey items even as adults, also generally stop caudal luring upon reaching adulthood. In their 2005 paper, Rabatsky and Waterman also tested a hypothesis made by Neill that males of sexually dimorphic species that perform caudal luring, such as pygmy rattlesnakes, will have better success rates than females. The theory is that a longer tail segment in males compared to females will be better able to mimic movements of different types of organisms, and therefore will seem more desirable or more realistic to the intended prey. In support of the hypothesis, they found that it took juvenile males less than half the time it took juvenile females, on average, to lure prey within striking distance while caudal luring, as shown in [link] (although only one individual prey was attacked within a 30 minute trial period).