The lizard had already been handled for 5 to 10 minutes and seemed to tolerate it, but this time it dropped its tail, apparently intentionally, though it might have been accidentally broken. This Woodland Alligator Lizard was found missing most of tailĪs we were photographing a Forest Alligator Lizard, my herping companion picked it up to get a better pose. (You can see the tail wriggling after it was detached in the video to the left.) This adult Desert Night Lizard detached its tail as a defensive measure. The video has been edited to show the wriggling tail as it slows down over about 4 minutes.) This video shows the detached tail of a Desert Night Lizard as it wriggles on the ground.
Bluetail lizard windows#
Lizards: windows to the evolution of diversity. (Much of this information here comes from this book: Eric Pianka and Laurie J. This should serve as a reminder that damage that can be done to a stressed lizard, even during careful handling, and a warning to always be careful of the tail when handling a lizard. They were all either intentionally released by a lizard that was stressed by capture or they were accidents of handling when the lizard's tail was pushed against a hard surface and it broke off, either intentionally or not. None of the detached tails shown below were broken off intentionally.
The needs of reprodution become more important to adults than the extra survival benefits of the tail loss defense. This is because adult females need the extra energy stored in the tail for the production of eggs or young, and adult males need the energy to court females and fight off other males. But the bright color on the tail often disappears when a juvenile becomes an adult. This helps the tail to be more visible to predators which lets the lizard use its tail loss defence. The tail of a juvenile skink is usually bright blue or bright pink. It is not uncommon to find lizards in the wild with no tail or with a partially regenerated tail, so tail autotomy apparently works. Regenerated tails are made of cartilage instead of bone, but they can also be broken off.
Tail loss in juveniles can also delay growth and sexual maturity.īroken tails do grow back, but these regenerated tails are often not as long as the original. it could impair the lizard's ability to run quickly or balance itself while climbing, and a male lizard's attractiveness to the opposite sex might diminsh along with its social standing. Losing the tail does not seriously harm a lizard, and may save its life, but the loss of a tail might have some negative effects besides a loss of stored energy. It's hard to know if a lizard is intentionally trying to detach its tail, but it often appears so. Sometimes a lizard will thrash around a damaged or partly-broken tail until it breaks off completely.
But often the tail loss is the result of a predator grasping the tail and breaking it. They accomplish this by contracting muscles at the base of the tail which break the vertebra. Some lizard species can voluntarily lose their tails even if little external force has been applied to the tail. Some lizards, such as skinks, are also known to eat their own severed tails for the energy stored in them. Since lizard tails are often used to store fat, they will provide some energy to a predator that eats it, and this might help the lizard by keeping the predator from searching for it again. This distraction allows the lizard to escape while the predator is left holding or trying to catch the detached tail. The broken part of the tail falls to the ground where it continues to wriggle like a living creature, distracting the predator away from the lizard's vulnerable body, sometimes for as long as five minutes. Tail loss is also called "tail autotomy" or "caudal autotomy" or "tail-shedding." Many species of lizards are able to lose part of their tail to help them escape from a predator.
Defensive Tail Loss as a Survival Strategy
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