What is a Desert?

I've been writing about deserts for awhile, but it seems that it might be a good idea to define what a desert is. The most basic definition is that a desert is an area that is moisture deficient; more water evaporates than is received. Another definition, more quantitative in nature, says areas that receive no water for at least 12 consecutive months are extremely arid lands, those that receive less than 10 inches (less than 250 mm) a year are arid lands, and those that receive 10-20 inches (250-500 mm) a year are semiarid lands (steppes rather than deserts).

One of the characteristics of deserts is that they have large temperature fluctuations due to the lack of humidity. Daytime and nighttime temperatures may vary by over 50 degrees Fahrenheit (10 deg C). (Keep that in mind if you're packing for a trip to the desert!)

Deserts are not necessarily hot. Antarctica classifies as a desert because of the small amount of precipitation it receives. In fact, over one-third of the land masses on our planet are considered to be deserts. Sand covers only about 20 percent of deserts, with a variety of soils, bare rock, and even ice constituting the other desert bottoms.

The word desert is derived from the Latin desertum, which means "unpopulated place." That was largely true at one time, but due to humans creating diversions and developing the combustible engine that pumps groundwater up to the surface, over 500 million people live in the deserts. Desert cities include Phoenix, Arizona; Riyadh, Saudi Arabia; Greater Los Angeles area, California; Dubai, United Arab Emirates; Juarez, Mexico; and many others.

Although at first it might appear that few plants and animals live in deserts, biodiversity is often high. Animals might not be readily seen because some spend part of their lives in burrows to escape temperatures that are not conducive to their lifestyles, while others are primarily active at night. Some animals (like kangaroo rats) have evolved to be able to live without drinking water by creating water during metabolic processes when they digest food. Plants are often drought- or salt-tolerant to be able to withstand the harsh conditions. Some desert plants have long taproots to be able to reach underground water.

Humans have adapted to survive in the desert by being nomadic to find food and water sources. Traditional desert dwellers include the Bedouin, Tuareg Tribe, and Pueblo people, who live in hot deserts, and the Inuits, who live in a cold desert. Many more people have moved to the desert in the last 75 years due to the invention of air-conditioning and highly engineered water systems.

Common Lizards

A trip to the desert just doesn't seem complete unless you see some lizards. Lizards are reptiles, and are generally fairly easy to spot because they make a rustling sound as they move around on feet with five-clawed toes. Getting a good look at one can be difficult, though, because they move so quickly. So I've done the hard part for you. I've found some lizards, managed to photograph them, and spent hours flipping through my A Guide to Field Identification of Reptiles of North America and then went to the internet because the entries are much more interesting. Here's what I found out.
The desert horned lizard (Phrynosoma platyrhinos) is a pudgy-looking lizard, and because it's so cute I get more excited about seeing this one than most others. It has small horns on its head (imagine that), and cryptic coloring that allows it to blend in with its habitat. It's one of about seven horned lizards found throughout the deserts of North America.

With its orangish head, this lizard doesn't blend in as well with its surroundings. As best as I can tell (and if you're a herpetologist and know better, let me know), it's the orange-headed desert spiny lizard (Sceloporus magister cephaloflavus), which has a wide distribution throughout the North American deserts. One cool thing about this lizard is that if the temperature decreases, it can turn its dark spots even darker to soak up even more heat. 

This sagebrush lizard (Sceloporus graciosus) can be distinguished from its close relative the western fence lizard (Sceloporus occidentalis) by its longitudinal stripes that run parallel along its body. As you can probably guess, the sagebrush lizard likes to hang out in sagebrush habitats. What you might not guess is that this little guy is a voracious ant eater. It will also eat other insects and arachnids. 

Here's another view of the sagebrush lizard checking out its surroundings. (I can just tell it's thinking "How close should I let her come to take her freakin' photograph?") They are quick to frighten, and they take refuge under bushes, in burrows, or wherever they can get away from you. They mate in the spring, typically lay a clutch of four eggs in June and the eggs hatch in August. I will soon be on the lookout for them so I can show you. (Please pretend you care.)

I should mention that if you come out to the desert in really cold weather, you won't see any lizards. They aren't that dumb. They like to wiggle into loose soil or hide in other animals' burrows to keep a relatively constant temperature. If you are trying to find lizards in warm weather, one of the best techniques is to go to some lizard habitat (a golf course is not good habitat), and sit still. Eventually a lizard will run by. You don't have to do anything except sit there. See, I knew I could convince you to like lizards!

Please Practice Safe Eating

We're recovering from a stomach bug. Desert Boy managed to escape it, perhaps because he uses safe eating practices. 

Desert Destination: Zion National Park

Every Monday we visit a desert destination.

Located at the junction of the Mojave Desert, Great Basin Desert, and Colorado Plateau, Zion National Park preserves over 200 square miles of exceptional terrain. Nearly everywhere you go, the views are stupendous.

Last week, Desert Boy and I headed to Zion to meet up with Uncle Andrew and his friends. It was hot, so we decided that the best afternoon hike would be in the Virgin River.

The river was flowing 43 cubic feet per second (cfs), and there had been no recent storms, so the water was clear and usually about knee high. But in some places the water was shallower, and in others deeper.

We hiked upstream with some of the other 2.5 million visitors that Zion receives each year. Some of the footwear was quite interesting--and some people chose to wear no footwear at all--ouch!

After a couple hours we reached the junction with Orderville Canyon. That canyon was narrower and the water warmer, so we headed up it. It had some interesting obstacles to negotiate.

Desert Boy didn't mind getting his toes wet.
And he delighted in playing in the water and sand.

Eventually we got to a place where we could go no further. So we enjoyed the view and headed back downstream.
The crowds had thinned out and we had a few moments where we felt alone in the impressive canyon.

The entire hike took about 5 or 6 hours, including many stops. It was a tiring but fun hike. Most importantly, we all came back alive.

Surviving the Desert: Don't End up like This!

This is Bobby. He made the unfortunate mistake of going on a hike with my brother. This is how he ended up. Before long the turkey vultures came in and started nibbling on him. Then they became more voracious and pulled pieces of flesh from his hot body. Coyotes made off with the camera equipment. And at night scorpions came and picked away at what was left of him. The sad thing is that it didn't have to happen. Here's how he could have prevented this terrible accident:

1. Don't go hiking with my brother.

2. Take plenty of water. And drink it. In the desert your sweat contains lots of salt, so consume some salt in the form of electrolytes in a sports drink like Gatorade. Or eat Cheetos. Seriously, they will help you from becoming hyponutremic (salt deficient).  (Good word for the day, see if you can use it in a conversation today). 

3. Dress appropriately. Keep from getting sunburned with long pants, long-sleeved shirt, and a wide-brimmed hat. Wear ankle-supporting boots. Use sunglasses (you got this one right, Bobby).

4. Be in good physical shape. Overexertion in the desert heat can tire you out even faster. Know your limits and don't exceed them.

5. Have a plan. Know where you're going and how to get there. If you don't arrive within a certain time period, have a preplan that your contact will notify authorities and start searching for you. Trust me, helicopters are better than turkey vultures flying overhead when you think you might be dead.

6. Don't go hiking during the heat of the day. Seek shade and do your hiking during the cooler hours.

7. Don't go hiking with my brother.

Memorials can be sent via the comment section of this blog. I'll be sure that they get passed on to Bobby's friends and family.