Tail-ing lizards can be frustrating experience for predators

February 13th, 2009 - 5:40 pm ICT by IANS  

Washington, Feb 13 (IANS) Ever tried cornering a lizard, you’ll know they can easily give you the slip by detaching their tails and scampering to safety.
Gary Gillis from Mount Holyoke College, said up to half of some lizard populations seem to have traded some part of their tails in exchange for escape.

This made Gillis wonder how this loss may impact on a lizard’s mobility and ability to survive. Specifically how do branch hopping, tree dwelling lizards cope with their loss.

Teaming up with undergraduate student Lauren Bonvini, the pair began encouraging lizard leaps to see how well the reptiles coped without their tails

But how well would the animals perform without their tails? Encouraging the lizards to drop their tails by holding them, just like a hungry predator would, Bonvini then persuaded the tailless reptiles to jump while Gillis filmed them.

As soon as the first animal took to the air, Gillis knew something was different. ‘It looked weird’ says Gillis, ‘the animals became blurred as they jumped. I called Lauren over and said “you’re not going to believe this.”‘

Replaying the animal’s jump in slow motion, the team could see that the animals were tumbling backwards uncontrollably as their tail stump flailed around. Filming other tailless anoles, three more backflipped out of control, although two others seemed to manage their trajectories better.

Teaming up with Duncan Irschick to analyse the reptiles’ leaps, the team could see that everything about the tailless lizards’ take off was exactly the same as it had been before they lost the appendage.

Things only started to go wrong as they left the jump stage. The lizards began flipping back by more than 30 degrees; some tumbled so far that they landed on their backs. The team also realised that as the animals took off, they raised the base of their tails as the rest of the appendage trailed along the ground, as if it was somehow stabilising the take off.

‘If jumping and landing are important for lizards, they are really compromised,’ says Gillis. ‘Coordinated landing on a branch is out of the question when spinning backwards,’ he adds. Escaping lizards probably pay a significant ecological cost for their life saving quick release system, said a Holyoke release.

These results were published on Friday in The Journal of Experimental Biology.

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