And what do all these hikes have in common? Good exercise, fantastic views, sweat, dirt, and lizards.
Have you ever been hiking and noticed that sometimes lizards do these weird displays which involve push-ups and displaying their dewlap (that colored sack of skin usually below the chin that many animals - birds, frogs, lizards - have and often puff out)? Ever wondered why they do that?
Imagine being a lizard, and trying to communicate to other lizards. There's lots of background movement outside - other animals, plants swaying in the wind, hikers - so how does one lizard know to pay attention to another lizard?
It's like this: you're at a party, there is a lot of ambient noise, and the party host wants to get everyone's attention. When does he do? He doesn't launch directly into his speech; he taps his fork against his glass. Then everyone directs their attention to him.
Researchers Terry Ord and Judy Stamps (of Harvard and UC Davis, respectively) wondered if those strange lizard push-ups serve a similar function. They speculated that only in situations when it is tough to get the attention of other lizards - in dim light, or when lizards are farther away, for example - would lizards use the push-ups to alert other lizards around that an important message is coming.
So how did they investigate this? Robot lizards. Obviously. Robot lizards doing push-ups in dim light.
And they confirmed their hypothesis: in poor light, lizards paid attention to the robot more quickly when the display was preceded with the push-up alert. Under bright light, there was no difference between displays with or without the preceding push-ups. (For you scientific types, here's the in depth research explanation)