Anza Borrego Field Herping

I was listening to the weather report on the news with only half an ear on my way to work, until they mentioned we were about to experience a record heat wave. My adrenaline and my interest piqued suddenly and I was instantly glued to the radio. Why anyone would get excited about record-breaking heat is no doubt beyond some people’s idea of a good thing. For me and other field herpers, it is just the opposite. It meant that the Anza Borrego Desert would get into the 100˚F range during the day and then drop to about the 70˚ mark at night, which are perfect “road cruising” weather conditions. “Road cruising,” for those unfamiliar with the term, means driving (typically at night) searching for herps on the road who have come to soak up the earlier day’s heat.

Just about anyone interested in “field herping” who lives in San Diego has traipsed out in the middle of the night to stalk the lonely highway leading to Scissors Crossing on the Western entrance to Anza Borrego Desert State park. The lone desert highway I refer to is the S2 County highway. The S2 is part of the Great Southern Overland Stage Route of 1849. Scissors Crossing is known to most field herpers as a place to experience reptiles that are indigenous to that area. Scissors Crossing Kingsnakes Lampropeltis getula californiae and Barefoot Geckos Coleonyx switaki are both found there and have been documented. The patterns of the Scissors Crossing Kings are said to be interesting and have been bred in regular numbers in captivity so collecting in the wild is no longer needed. Personally, they looked like a striped Desert California Kingsnake and really have no distinction from other forms that I can see.

I have yet to see a Barefoot Gecko Coleonyx switaki in the wild but that wasn’t our target species on this trip. We were after geckos, but one of the more “common” species that is found within the Anza Borrego Desert. We were searching for Coleonyx variegatus variegatus, which is known commonly as the “Desert Banded Gecko” and is found throughout the Anza Borrego Desert. Seeing them in the wild, while not as rare as the Barefoot Gecko Coleonyx switaki is still somewhat difficult.

Imagine if you will, driving at a speed of 25 to 30 mph down a desert highway and spotting a cigarette butt lying in the road, colored pale yellow with dark brown bands that run horizontally. Now you have an idea of what it’s like to try to see a Desert Banded Gecko while road cruising. Adults average two to three inches in total length and the males are easily distinguished because of spurs on two obvious bulges just after the cloaca and before the tail. As I said earlier, they are a pale yellow ground color with a brown horizontal banding very reminiscent of baby Leopard geckos Eublepharis macularius.

I came home from work and asked my wife if she’d like to go herping. She agreed it would be fun and called in sick to work (hope they don’t read this article) then began packing water, snacks, etc. meanwhile I packed up the snake hooks, tongs, and field guides. We made our way into the desert and began our search of the S-2 with vigor, our eyes wide with anticipation. Driving along some of the few “residential” roads, we came across a couple of Western Shovel-nosed snake Chionactis occipitalis about six to 8 inches in total length.These snakes are reportedly hard to catch if they are in the sand. We were lucky enough to catch ours basking in the road. They are one of the few insect-eating snakes and mainly feed on scorpions, centipedes, and moth pupae. As the name might imply they are a burrowing snake. While this was a great find that added to the trip, we still had yet to find our target.

We drove for almost an hour seeing various species of stick snakes (otherwise known as branches) and rubber snakes (otherwise known as radiator hoses/fan belts). We drove about half of the length of the S-2 when I spo tted a dark round shape on the road. I couldn’t identify it with any certainty so we turned around to figure out exactly what it was just as we had been doing all night. When we were about two car lengths away, I could establish that the color was grey and almost matched the asphalt of the road itself.

We stopped the car within about six feet or so, all the doors came open simultaneously as if by a single motion, we all got out with flashlights, and I with a snake hook. In seconds, I called out “Sidewinder”. I could tell just by the look of the overall snake that it was indeed a Sidewinder! From later use of the Peterson Field guide, we identified it as a Crotalus cerastes laterorepens, which is known as the Colorado Desert Sidewinder.

The Sidewinder Crotalus cerastes, when compared to other Rattlesnake Crotalus sp. I have encountered, is never shy about showing its displeasure of being discovered. This one in particular rattled continuously from the time it felt the approaching footsteps, to long after we re-entered the car and ceased moving. The car was not running, but it seemed as if the snake could still sense us there, even though it exhibited no tongue flicking activity. We found two more of Sidewinders and apparently all of them were the same subspecies because they all had the black basal segment said to identify the Colorado Desert Sidewinder Crotalus cerastes laterorepens. One in particular showed its displeasure in the usual way of tongue extension. This is typical Rattlesnake Crotalus sp. behavior. When severely agitated they will push out their tongue and hold them out either curled over the top of the face or downward towards the lower jaw.

About this time, I am thinking that we should be encountering the Desert Banded Gecko C.v.variegatus that we had originally come out for. My family and I were about to leave the desert for the night and head back home for some rest, happy, but still disappointed we had not seen our target species. It was at this time that I noticed a vehicle following us. Now in case anyone is unaware, it is illegal to collect anything in most state parks. My family and I are aware of this and do not collect, but simply go and photograph those species that we are searching for.

As is usually the case whenever I go out to the S-2 to photograph at night, I see the all too familiar red and blue lights of the Border Patrol flashing in the rear-view mirror. Since I have been going out to Anza Borrego every spring for several years, I am quite used this. The Border Patrol finds that slow-moving vehicles, which seemingly stop at random occasions to be somewhat suspicious. Which given our proximity to the border is quite understandable. As always, I await their approach and answer the same question that they always ask. “What are you folks doing out here?” I explain the officer that I am out here with my family photographing snakes and other reptiles that we find on the road. Previous experience proves that the officer unbelievingly asks that I repeat myself and runs the licens e plate and my drivers’ license then tells me to have nice night. This occasion was not one of those.

This officer runs the plate and drivers’ license and then asked me to wait one moment. He called to the other officer on his radio, and asked the other officer where he had seen a snake earlier, and came back and relayed the information to me!

After this, we of course went in search of this snake knowing it was probably fruitless but trying nonetheless. As is usually the case in many herping adventures, the best occurs when you least expect it. We never did find the mystery snake the Border Patrol officer referred, to but in the same area we did find our target species Desert Banded Gecko C.v.variegatus. Four of them actually, along a short stretch of the S-2. It would seem that the males were out looking for females this night, because within a 1 mile or so stretch we find four separate males all on the road seeming to soak up the left over desert heat. We photographed them and then watched them scurry off into the desert night, going on about their business. A strange night to say the least, but one that I will not soon forget. Another eventful mission, this time a splendid success.