A Quick Trip To The Desert
It's 0615 on a Sunday morning and I'm on a commuter flight to O'Hare, en route to a work-related conference in San Diego. The conference doesn't start until Monday, but I want to get out there as early as I can. I want to get one more herp trip in if it's possible. Responses to inquiries made to some herp newsgroups indicate that I may have a chance to observe some reptile life out in the desert to the east, even though it is the middle of November. I cannot pass up a chance to herp somewhere new and exciting, especially when the frost is on the pumpkin back at home.
Switching planes in Chicago, I arrive on the coast around 1030 AM, Pacific Time. I have my rental car by eleven and by noon I have left San Diego far behind as I head east on I-8. Pine-covered hillsides give way to rock-covered hillsides as I drop down into the low desert, heading towards the area south of the Salton Sea. It is a bright sunny day, the temperature in the mid-fifties, and I am heading for parts unknown and sights unseen.
Most of the hillsides are covered with large rocks, which are rounded smooth - there are few sharp edges or fracture planes to be seen. Thinking it over, I realize that cycles of heating and cooling are splitting these hills and mountains down to their very bones. The sand-laden winds scour away the evidence over time, smoothing away the rough work of fire and ice.
I'm still dropping down into the low desert when signs indicate a county park at the next exit, and public land is just what I'm looking for. When I reach the parking lot I find the park to be one of those boulder-strewn hillsides I saw from the highway, with hiking trails and a scenic overlook. Getting out of the car, a steady and brisk east wind hits me in the face, which is a bit dismaying, chilly wind not making for the best conditions for observing reptile life. Then again, the sun was bright and still high in the sky, so perhaps some creatures were basking in some nook out of the wind.
I made my way between jumbles of rocks and boulders, many of them larger than my rental car. Their rounded shapes made many interesting niches and hiding places where two or more rocks came together. Down in this rocky maze I realized I was sheltered from the wind, and I could feel the sun's warmth on the rock surfaces, which made me feel a little better about my chances this day.
Sure enough, I saw a flash of lizard as it disappeared around the curve of a boulder. I readied my camera and followed after, moving slowly and carefully. There it was! It was a fair sized Banded Rock Lizard, Petrosaurus mearnsi, basking on a near vertical surface. I managed to take a few photographs before the lizard decided to move into the safety of a deep crevice. There are several species of Petrosaurus inhabiting boulder piles from deep in Baja California up to here in Imperial County. P. mearnsi is one of several "Baja endemics" that range up into the southern tip of California. These lizards are two to three inches in length from snout to vent, seven to nine inches in total length. Their limbs are robust, and there are several long toes on each hind foot. The back legs are held out away from the body, which is kept low to the ground, giving the lizard a slow waddling gait when not frightened. It is hard for me to tell how they run, for they are a blur when they want to get away.
I conjured up an image of these boulder fields stretching south from here for hundreds of miles, down into the Baja peninsula. Down there somewhere warmer breezes blew, and Petrosaurus, Chuckwallas and other lizards bask in comfort all winter long.
Prowling further amongst the boulder piles I spotted several more Rock Lizards, all of them sunning in the lee side of boulders, out of the wind. They would move away quickly, but I noticed they never ran very far, either to some protective crevice, or far enough around a boulder to disappear from sight. In profile, the head and body of these lizards appear very flat, which I suppose allows them to take advantage of smaller cracks and crevices. Petrosaurus is a true saxicolous, or rock-dwelling, lizard. It lives in no other habitat other than the rock pile.
Somehow a couple of hours had passed, and I was very thirsty - the steady desert wind sucks the moisture right out of your body, it seems. The human form is not designed to retain water as well as Petrosaurus or some other lizard can. Having covered only a small section of the hillside, I headed back to my car for some water.
The afternoon was getting on, prompting me to move on. I wanted to check out a spot on the map called Fossil Canyon - how could I resist a name like that? I continued east, still shedding altitude, until I reached Ocotillo, a wide spot on the road down on the desert floor. I stopped for gas and more water, and then headed north for a few miles, turning off on the gravel road leading to Fossil Canyon. I ran out of road just short of a large upthrust cut by a narrow gap - Fossil Canyon, I guessed. The towering layers of pinkish rock were capped off with a thick brown sedimentary layer. As I walked along, small lizards skittered from rock to rock. I tried in vain to capture one, or at least get close enough for a positive identification or to take a picture. They were sceloporids at least; I suspected they were Yellow Backed Desert Spiny Lizards, Sceloporus magister uniformis, a species of the desert floor that hide and live amongst rock and brush. I kicked up a few more as I wandered up the canyon floor. Something different ran under a creosote bush, a bit larger in size. I ran it out of the bush - it was a Whiptail, with very faint broken stripes on its back, probably a Great Basin Whiptail, Cnemidophorus tigris tigris. I couldn't get close to this lizard either - it just wasn't my day! If I had someone with me, I might have been able to corner one.
I walked up the canyon a bit further, enjoying the scenery, but a turn of direction and the low angle of the late afternoon sun threw the canyon ahead into the shade. I doubted I would find much else in the cool darkness, so I turned back. I wanted to cruise the blacktop roads a bit before they cooled off, so it seemed like a good time to start.
I was soon heading north into the Anza Borrego Desert, on a two lane blacktop. At dusk I stopped the car and put my hand on the pavement - it didn't seem very warm. I guessed that the steady wind pulled the heat away, much like it pulled the moisture out of me. A couple of large black beetles bumbled across the road, looking much the beetles I'd seen crossing Texas roads at dusk. That was all I saw on the roads that night. The sun slid down, and I got lost in the dark, on the winding roads that switchbacked up and down the hills and valleys. I tried to bear west as best I could, and ended up near Escondido, north of San Diego. A long shortcut got me back to my hotel after midnight, to end a long day feeling smug at taking advantage of a small window of opportunity.
The conference hotel has a small creek running behind it, which I visited during lunchtime the next day, enjoying the warm sun. There is a flash of dark brown on the trunk of a willow tree that looks to be a small swift, a Great Basin Fence Swift to be precise. It looks just like the Northern Fence Lizards do back home, perhaps a shade darker. It too, is enjoying the sun, and is still on the tree trunk when I return from fetching my camera, along with several more swifts. Now I don't have to leave the hotel to find new species! I enjoyed their noontime company the rest of that week.
I'd like to come back out to southern California some day, at a better time of year, and see what else I could find - and preferable for more than six hours!