Lizards' foraging techniques influence their ability to walk, run

Washington, Apr 22 : Researchers studying animal behaviours have revealed that lizard's hunting styles affect their ability to walk and run.

Doctoral student Eric McElroy along with his team studied the mobility of 18 different species of lizards, such as skinks, iguanas and monitor lizards, as they walked or ran, to understand the link between their foraging styles and their biomechanics.

They found that lizards used two basic hunting approaches. The first approach was sit-and-wait where the lizards spend most of their time resting on one location waiting for their prey to pass. Then, with a quick burst of speed, they run after their prey, snatching it up with their tongues.

The second approach is known as wide or active foraging, where they moved constantly but very slowly in their environment, using their chemosensory system to stalk their prey.

Stephen Reilly, co author of the book Lizard Ecology and professor of biological sciences said that some wide foragers are moving about 80 percent of the time while sit-and-wait foragers may move only about 10 percent of the time.

While all lizards have the ability to run, the study found that sit-and-wait lizards didn't walk. Lizards that use the sit-and-wait method of foraging use running mechanics even when moving at slower speeds.

However, wild foragers involved their walking mechanism. They must move at slower speeds in order to use their advanced chemosensory system to locate their prey.

For the study, the researchers used a race-track and high-speed video camera to record the forces generated by the lizards and record their movement at various speeds.

They later collected the data and analyzed the video to determine whether the lizard was using running or walking mechanics.

The researchers said that foraging and locomotion are so closely linked, in fact, that three groups of wide foragers that used the sit-and-wait approach actually lost the ability to walk.

"The most interesting aspect of this research is that it demonstrates a clear link between animal behaviour and functional morphology," said McElroy.

"It's quite amazing and surprising that the behavioural diversity that everyone knows about and is inspired by is grounded in form, function and physiology," said McElroy.

ANI