Friday, October 7, 2011

Schuett/Repp Suizo Mountain - Crotalus scutulatus

Howdy Herpers, 5 October 2011

I got off to a bad start on the evening of 27 August. I hopped out of my truck, and prepared to open a data sheet by placing a thermometer in a nearby palo-verde tree. The fact that moments later, I forgot which palo-verde tree I thrust said thermometer into was the beginning of the bad start. Anybody who works after nightfall with various instruments of science scattered about knows the danger of not paying rapt attention to placement. The darkness that is often associated with nightfall can make even the simplest chore a nightmare in flandickery if full focus is not applied at all times.

As an amused Blake Thomason looked on, I walked in circles around the various pieces of surrounding shrubbery, muttering curses and bitch slapping myself incessantly. After about ten minutes of this, Blake took pity on me, and began to scour the area around our parking lot as well. About two minutes later, he called me over and said: "Hey Amigo--look what I found!"

Image 1: "Hey Amigos--look what Blake found!" It's a Mojave Rattlesnake (Crotalus scutulatus), only the second one ever found in the 10.5 year duration of the Schuett/Repp Suizo Mountain study. This is an in situ image of the snake as Blake found it--less than 20 feet from our parking spot!

The previous Mojave Rattlesnake was found 22 July 2009. At that point in time, we didn't have the means or desire to radiotrack a "scut." We were fearful that since they don't normally occur on our plot, we might have a wayward snakethat would wander well off plot and be lost.

Image 2: However, with the scut found on 27 August, we decided we'd try our hand at tracking him--regardless of any would-be wandering. This is obviously a posed image, taken the day following the capture.

In no time flat, we had a transmitter in him, and began tracking.

Image 3: In the early going, tracking good old Blake the snake went slicker than greased owl scat. On 7 September, he was found behaving very atrox-ish, coiled in prickly pear next to a pack rat midden. His total move was ~100 meters to the southeast of his capture spot. He had wrapped around to the south side of our hill. I expected him to move southward, out to the creosote flats by Park Link Drive.

Image 4: Knowing that this snake might just boogie right off the plot, staying with him became imperative. The next tracking session was on 11 September. He had shifted westward about 100 meters, and had actually crossed Main Street.

Image 5: I tracked him again on 13 September. He had shifted about 200 meters to the northwest. Thus far, there was nothing to indicate that there was trouble ahead. 

On 17 September, I could not get his signal from our normal parking spot. Blake the person and I took a drive to the top of Iron Mine Hill, and picked up a very faint series of blips. They were coming in from the north, and the weak blips indicated he was a LONG way out there. We drove back down the hill, (encountering my shadow, tortoise number 505 on the way down), and headed across Suizo Wash. We got the signal from the other side. At that point, as we had three other people waiting for us at the parking spot, we drove back and formed a two truck caravan to work the back roads that occur haphazardly around the countryside. We drove around for over an hour, the results being akin to the sound of one hand clapping. My companions were still gung ho to keep trying, but I pulled the plug on the effort. We were out there to find new snakes, (which we did-but that is another story), and I wasn't about to waste five pairs of eyeballs by driving around all night in no mans land looking for a lost child. (The thought of putting his image on a milk carton occurred to me. "Have you seen this child?")

On 24 September, the same scenario repeated itself. I drove to the top of the hill, once again freaking out poor old tortoise number 505, who was peacefully munching on some grass at the edge of the road. The signals came in ever-so-faintly, and I drove to the edge of the earth with zero luck again.

Great feats of deep thinking began. How did I do this back in the day when we had big male Black-tailed Rattlesnakes that would take off? Then it hit me. The next time I got the signal, I would make cock sure of which direction it was coming from, and hike him out. None of this driving wildly around on back roads hoping for a convenient parking place. Hiking them out is what I used to do with lost children in the past, before I got fat and lazy.

Thus it came to pass that on 28 September, I drove to the top of Iron Mine Hill. Once again, poor old 505 was choking down some dry grass at the edge of the road. This time, he paused long enough to give me a dirty look, and then continued to browse. Once again, a faint signal came in, this time from the northwest. I aligned my compass in the direction, and noted that I could get about 100 meters closer to him by driving to a place that was in direct line with the compass/signal.

I started the hike at 1715. I told myself that I would walk until 1810 before I threw up the white flag. At precisely 1800, the first faint blips appeared again. The crowd went wild!

Image 6: By 1815, I had tracked him down. He had moved an astounding 1,885 meters from his point of capture. As good fortune would have it, he followed the one road that leads in that direction. I could have driven and parked right beside him that night.

On 1 October, another drive to the top of our hill yielded no tortoise 505, and no signal. Off we went on a wild drive to try to find the signal, with no luck.

On 2 October, John Slone joined me for another attempt. At the last possible second, we caught a faint glimmer of a signal. It wound up being nearly an hour later, but we finally we tracked him down.
Image 7: He was now 4,280 meters northwest of his capture spot. That is over 2.6 miles!

Image 8: And of course, when we found him, he was traveling in that same northwest direction he has been heading since we first found him. Just after this image was taken, he exploded into a defensive posture, rattling and loudly hissing. He was not glad too see us! 


The paved road gradient that leads to our plot takes one through some changes in the landscape that in turn leads to changes in the herpetofauna that inhabit the region. To the west end of the road, Sidewinders, Mojave Rattlesnakes, and Desert Iguanas can be found. These all peter out together about one wile west of our plot. We knew when we installed the transmitter that we might be in for a difficult subject to track.

Blake the Snake is probably one of those rare individuals that cut loose from a smaller home range to check out the world around him. He found us at the eastern edge of his journey, and that was likely not a good experience for him. I speculate that he is now heading back to his home range. As one who has herped the whole length of the area, I have only once encountered a Mojave Rattlesnake once in November.
That means Blake the Snake is going to hibernate soon. If I can stay on top of him until that point, we probably will have him at the point where he is back home again.

Image 9, By Royce Ballinger. View from Iron Mine Hill looking northwest. To the left background, local herpers will recognize Picacho Peak. To the right, the Picaho Mountains. Smack dab in the middle of the two mountain ranges is the lone hill that is called "Huerfono" (The Orphan in Spanish). Blake the Snake is slightly past Huefono, and about 1/2 mile to the north. 

This here is Roger Repp, signing off from Southern Arizona, where the SNAKES are strong.......................

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