Spotted a lizard doing push ups? Here's why they do it and why they don't get tired of doing it.

Lizards' push-up movements are actually a form of communication. Both male and female lizards can perform push-up displays.

Pick a sunny day. Drive down Mule Pass just outside of Bisbee. Go through the tunnel. Find the trail that starts under a tree. Trek up Mount Ballard 7,000 feet, and look carefully. There, in the ...

A genetically distinct population of Yarrow's spiny lizard in Arizona's Mule Mountains is facing local extinction due to climate change. Conservationists have petitioned to list the lizard as a ...