A New Old Tortoise

My buddy Justin posted a link to a paper on Facebook yesterday:  “The desert tortoise trichotomy: Mexico hosts a third, new sister-species of tortoise in the Gopherus morafkai – G. agassizii group”. I’ve been waiting for this; it’s been known for some time that Gopherus populations in southern Sonora and northern Sinaloa are genetically distinct.  The tortoises that roam the thornscrub and tropical deciduous forest have finally been described as Gopherus evgoodei, and reading the paper brought back memories of my own encounters with this new species, on my first trip to Mexico with some friends back in 2011.

We spent a number of days herping in southern Sonora, and on one of them we visited a bio-preserve in the tropical deciduous forest above Alamos, with Gaby, our local guide who was involved with a tortoise tracking project on the preserve.  We were met at the gate by a trio of local guys with a beat-to-shit ranch truck.  We might have been in a bio-preserve, but we would be crossing through some private ranches, and these men were here to escort us.  We paid them nine pesos each for wristbands that marked us as visitors; I was sweating so much in the heat that the band wouldn’t stick together.   I put it in my pocket.  We had an ice chest full of water and gatorade, and the señors loaded it in the truck bed and offered us a ride, but we elected to walk and herp and perspire profusely.  Near the gate, a bright green juvenile ctenosaur basked in the road and proved our point.

It was a hot, sweaty, three mile walk, mostly uphill.  Both temperature and humidity were in the upper nineties, and we were around eighteen hundred feet above sea level, high enough to make hiking even harder.  To make up for it, the views of the hills and surrounding countryside were spectacular as we marched through the tropical deciduous forest.  Red-Spotted Toads (Anaxyrus punctatus) scuttled underfoot, and Barranca Whiptails (Aspidoscelis costata barrancorum) fled at our approach.

We took a break to rest and rehydrate at a shady spot under a fig tree, where a rocky wash crossed the road.  Off to one side, among a scattering of large boulders, was a waist-high pile of stones.  It wasn’t until I saw the small wobbly cross that I realized this was no public works project – either someone was buried underneath that pile, or it served as a roadside shrine.  My speculations as to who was possibly under the rocks was interrupted by a shout from one of our escorts, who had spotted a snake among the rocks in the wash.  We lurched upright and trotted over; sure enough, there was a yard-long Boa constrictor imperator stretched out in a cleft between two boulders.  The last third of its serpent form was in the sun, and an bright iridescence played over the dorsal scales.  Here was our first live boa of the trip!

After photographs, we put the boa back among the rocks were we found it, and moved on up the road.  I’ve made a lot of long walks in my time, but this was one of the most difficult.  The heat, humidity and the upward slope were kicking our butts.  Walking single file up a rocky trail, we reached a long, narrow structure at the top of the hill.  This building served as a field station for biologists from time to time, and the walls along the veranda were decorated with cow skulls, deer antlers, horseshoes, ranch tools, and the shells of two gopher tortoises.  The view of the valley below and the mountains beyond was spectacular; I thought this would be a cool place to stay, a perfect retreat for naturalists and biologists.  Up in the porch rafters I spotted a Mexican Gray Cracker (Hamadryas februa), a new species of butterfly for me, and the sharp smell coming from the thatched roof spoke of bats and their guano.  I could see myself kicking back in a chair on that veranda at sunset, watching the shadows grow long and the bats flitter after a hot day herping in the TDF.

Gaby and another man readied the radio tracking gear, and then we set off around the side of the hill, into an area of thick, second-growth forest.  The steep hillside was covered with boulders and rocks, and the understory was lush and green, in part from the late summer rains.  There were patches of ferns here and there among the rocks; any tortoises living here would have plenty to eat during the monsoon months.  Gaby’s associate was running the receiver and antenna, and he pointed to a car-sized rock resting on two smaller ones.  “There are two tortoises under there,” said Gaby.  There was a deep crevice underneath the rock, and crouching down I could see two tortoise-shaped lumps about six feet back.  The crevice didn’t have enough height to get flash penetration back to the tortoises – there would be no clear pictures of those animals.  It was a perfect refuge, and it looked as if tortoises and perhaps other animals had scraped much of the soil out from under the big rock.

At the same time, Tim was poking around nearby, and found a tortoise out in the open.  It was a large male, without a transmitter; Gaby said there were plenty of tortoises on the hill that were not part of the tracking study.  Unfortunately, this tortuga kept his head tucked in his shell, and would not come out even when we retreated some distance.  We marked the location in hopes of checking back later and getting a better look at him.  The radio tracker continued on around the hill, and while we were shaded from the sun somewhat, the woods were close and humid, and gnats and mosquitoes quickly found us.

“Escorpión!”  The tracker had found a Beaded Lizard, wedged into a crevice at the base of some large boulders.  One of the guys got a hook behind it and pulled it out, and we were able to get a good look at it and take some pictures, while our escorts looked on and shook their heads at the crazy gringos.

It turned out that no other turtles were out in the open, so we headed back to Tim’s tortoise for another look.  It was still where we left it, but we could only see a pair the of beady eyes peering out from behind two scaly fore-legs.  That was as good as it was going to get with this turtle, and I was very disappointed – seeing ninety per cent of any animal, sans head, is not very satisfying.  Resigned to a long walk back, we headed down the hillside, and there was a tortoise, an adult female, walking close to the trail and with her head out!  She seemed unconcerned with our presence, taking bites out of leaves as she walked about, and I was able to get photos and video as she went along.  Occasionally she would raise her head and watch me watching her, and then return to her grazing.

And so our long, hot, sweaty walk paid off with a close look at a potential new species.  I only had to wait 4.5 years to have a real name pinned on a leaf-chomping turtle peculiar to the TDF.  Welcome, Gopherus evgoodei – I hope we meet again someday.

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