The tail lizard to become an acrobatic actor

If you've ever tried to catch a lizard, you'll find it a difficult task because the animal has an emergency self-defense system to hide. They simply break their tail to distract predators while they flee. According to Gary Gillis of Mount Hokyoke School, USA, about 50% of lizard individuals are able to trade a part of their tail to escape.

This caused Gillis to wonder if this loss had any effect on the lizard's ability to function and survival. Especially the lizards that live on trees how to deal with this loss. Collaborating with university student Lauren Bonvini, Gillis studied the lizard dance activities to observe their adaptability without tails.

Setting up a jumping box with boxes and newspapers, the two researchers gently encouraged the lizard Anolis carolinensis to jump from the 11cm high pedestal while they returned to the scene. The lizards perform this movement quite well, they jump by pushing their hind legs and landing gently. The measuring distance ranges from 14.9 to 29.9 cm.

When lizards break their tails to escape predators, its speed and agility are reduced. (Photo: High on Mount Holyoke).

However, how these animals perform jumping without a tail. Bonvini stimulated the lizards to break their tails by grasping them, like the predator's actions, and then acted to make these tailed reptiles dance. Meanwhile, Gillis recorded everything on the camera. As soon as the first lizard jumped, Gillis noticed something different. He said: 'It looks very strange, the animal suddenly becomes unclear when they dance. I called Lauren again and said 'you can't believe this' . Slowing down the animal's jump, the two found that the animal fell backwards and the rest of the body fell in many directions. Observe the other tailless lizards, there are 3 more upside down, though the other 2 seem to be able to control their movements.

In collaboration with Duncan Irschick to analyze lizard jumps, the team found that when lizards jumped, everything was the same as before they lost their tails. Things start to deviate when they finish the jump phase. The lizards began to roll backwards more than 30 degrees, some turned upside down so they landed on their backs. The team also found that when the animals jumped, they lifted the end of the tail, while the rest dragged on the ground as if trying to keep balance.

Gillis said: 'If jumping and landing are important for lizards, they are really badly damaged. Landing down a tree is completely impossible when they are turned upside down. To escape the enemy, lizards pay a heavy price. '

So how does this animal use its tail to ensure safe grounding? Gillis is not sure if the lizards turn their tails when jumping to avoid being turned around, or dragging the tail on the ground to help stabilize the ground. He also wanted to learn more about how this animal adjusts to live without a tail, and after the tail has grown back.

Refer:
Gillis, GB, Bonvini, LA and Irschick, DJ Losing stability: tail loss and jumping in the arboreal lizard Anolis carolinensis.Journal of Experimental Biology, 2009;212 (5): 604 DOI: 10.1242 / jeb.024349