Lizards we come across in the deserts of southeast Utah while doing our 'geologizing' and hiking usually scurry off when approached, so photos we take of them typically end up being from above and from a distance. But the yellow Great Basin Collared Lizard below was cooperative, climbing up on a rock and posing. These guys can be quick if they want to be, even running using only their hind legs.
Great Basin Collared Lizard (blue sky by Photoshop)
The spectucular small Greater Short-Horned Lizard below didn't run when approached and was nearly flattened under foot, initially unobserved.
Greater Short-Horned Lizard
Below is some detail (this rivals Hollywood, or maybe inspires).
Greater Short-Horned Lizard (detail)
Camouflaged on top to avoid predators (ravens?) but with an iridescent blue belly to catch the eye of potential mates (or scare off rivals?) is apparently the best arrangement for Eastern Fence Lizards, below.
Eastern Fence Lizard
The lizard below is on smooth slab of Navajo sandstone, and those spots are probably small concretions. Maybe it's a female Eastern Fence Lizard, or an Ornate Tree Lizard?
Female Eastern Fence Lizard, or Ornate Tree Lizard?
Below, another mystery lizard -- those blue specks ought to make it easy to identify but it's not in our field guide. This one was encountered in a wash near Murphy trail below the cliffs (ie., White Rim level) in the Island In The Sky area of Canyonlands. (Update, 2013: Zack Zdinak, at www.lifedraw.com, identifies this lizard as a male Common Side-Blotched Lizard, Uta stansburiana. This variant in Island of the Sky district is more subdued than those further west.)
Male Side-blotched Lizard
Male Side-blotched Lizard, detail
Small lizards routinely run up vertical sandstone walls when we approach them in slot canyons. What keeps their claws sharp? Maybe the claws are formed in cone-shaped layers.
Great Basin Collared Lizard, claws
Great Basin Collared Lizard, claws
The overhead view of the striped lizard below probably means that's as close as it'd let me come to it. Being cold-blooded, lizards are less frisky in the morning when temperatures are still low, but they aren't easy to see unless they move -- so a good time for photos is when it's warm enough that they move, but not so warm that they move a lot.
I think it's a Plateau Striped Whiptail.
Plateau Striped Whiptail
At most places in Utah, the elevation is about 1.5 or 2 kilometers higher than sea level (at that altitude, cars only need 85 octane fuel in Utah rather than the usual 87). The surface of Lake Powell is 1.1 kilometers above sea level, which we attained when hiking down to the lake at Hole-In-The-Rock, a gorge in the Navajo Sandstone used by a Mormons pioneer group to cross Glen Canyon. (Lake Powell isn't really a lake, it's a reservoir, created by damming the Colorado River at Page and flooding Glen Canyon.) On the hike down, which perhaps took us into a different climatic zone, we saw lots of Chuckwalla lizards basking in the sun. As you can see below, they're heavyweights, and big. Probably the vertical pose isn't their most flattering. They disappear into the rocks when approached (reminding me of mountain marmots).
The small lizard below Common Sagebrush Lizard, is indeed quite common in SE Utah. It likes to run a meter or so to get some distance and then stop to look back and do a couple quick 'push-ups' with its front legs. Here's a web page that describes research into what the push-ups might be about (I thought they might help with vision and range-finding via parallax, but apparently it's communication).
These lizards can run on a vertical sandstone wall -- up, down, or laterally -- at about twice walking speed. Here it is on a near-vertical sandstone face:
Common Sagebrush Lizard
Several lizards above have a change of colour and scale pattern where their tails connect to their body. Many lizards can shed their tails, and then even re-grow new ones. According to researchers (here) this helps them survive predation, especially snake attacks. It also stops me from trying to catch them, as I'd feel terrible if my trying to grab one caused it to drop its tail.
Once in a while we come across a snake. Here's one sunning itself in the morning, stretched out nearly straight (so it'll have to contract before it can go anywhere). I'd say it's a Gophersnake.
When backpacking, when it's windy, we want rocks to hold down our tent. Lifting up flat rocks often exposes scorpions. They are nocturnal and so hide during the day. When exposed they don't do much, so it was easy to put a reference scale next to the one below for the photo. The stinger is folded back over that white hemisphere on the end of its tail. When we find one, we typically put the rock back.
We leave shoes outside of our tent at night, and before putting them on in the morning, we check for inhabitants. I've never found anything but just imagining it keeps me checking.
Serradigitus wupatkiensis? Found at Navajo Point, high elevation (2.2 km).