How do tree-hugging lizards hang on during storms? With big toes

Tropical lizards have a stick-to-itiveness in high wind that puts TV weather reporters to shame. Now we know why, thanks in part to a high-powered leaf blower. 

Hurricanes Irma and Maria last year put a group of little tree-hugging lizards to the test, and scientists were perfectly positioned to see which reptiles survived and why. Then researchers cranked up the leaf blower to observe just how 47 of the Caribbean critters held onto a wooden rod. 

Under tropical storm-force winds, the lizards lounged. As the wind speed cranked up, they still held on, although it got tougher. 

[embedded content]

Even at 164 km/h, the lizards grasped the pole with two clingy front feet while their tails and back legs flapped in the wind like a flag. 

“All the lizard needs is an inside out umbrella and the image would be perfect,” said Harvard evolutionary biologist Colin Donihue.

But there’s only so much a little lizard can take. At 174 km/h, it was flying lizard time.

Don’t worry. No lizard was harmed in the lab test.

“They do go flying in the air, but it is softly into the net, and everybody was returned back home” unharmed, said Donihue, who led a team of researchers from Missouri, Rhode Island, California, Belgium and France.

‘Exciting insight’

The lizards’ secret weapon to surviving hurricanes? The survivors had six to nine per cent bigger toe pads, significantly longer front limbs and smaller back limbs, compared with the population before the storm, according to a study published in the journal Nature on Wednesday. Donihue said it’s the first study to show natural selection due to hurricane. 

By coincidence, Donihue and colleagues had been measuring and studying lizards just before the storms blew into the Turks and Caicos islands last September. They returned several weeks later to see if there was a difference in the surviving population. 

They found that the survivors were a bit lighter overall despite the bulked-up front. Key were those toe pads — they are, at most, about half the size of a pencil eraser — Donihue said. It also explains why island lizards have bigger toe pads than inland Central American lizards, a difference that had baffled scientists. 

Outside experts praised the study, especially the researchers’ luck of being in the right place at the right time. 

“This study provides exciting insight into the effects of extreme natural events,” said Pennsylvania State University biologist Tracy Langkilde, who wasn’t part of the study. ​

Source link

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.