The Mojave (Agassiz’s) Desert Tortoise
I’m lucky enough to live next to the threatened Red Cliffs Desert Reserve. The reserve, in southwestern Utah, covers a variety of beautiful terrain and contains a robust collection of desert animals. One of those is the threatened Mojave Desert Tortoise, also known more recently as the Agassiz Desert Tortoise. Due to cattle ranching, expanding cities, off road vehicle traffic and most recently a ballooning raven population the tortoise was listed as threatened by the end of the 1900’s. Then, in 2011 it was determined that the tortoises on the north and west sides of the Colorado River were actually a different species. This divided the population in half and resulted in two even more threatened species with the Agassiz Tortoise in Utah, Nevada and California, and the Morafka Tortoise in Arizona and Mexico.
They have dinosaur skin. I barely caught this photo of one munching a leaf. It had been casually strolling by when it suddenly lunged at the leaf like it was catching an antelope.
The Agassiz Tortoise spends up to 90% of it’s life underground, so many people live near them their whole lives without seeing one. I have spent enough time in the reserve to notice when they are active and have managed to see about 12 of them, enough to start seeing the differences in individuals. This past spring they seemed more active than in past years and I managed to find them a couple of days when I had my longer lens.
The tortoises live about as long as a human but only 2-5% of them survive to adulthood. Part of the reason for this is it can take up to 5 years for their shells to harden enough for full protection from predators. In recent years, Ravens have figured out that they can peck through the shells of the baby tortoises.
One day I came across this baby that was walking across the trail I was on. I had been walking for only a few minutes, so I ran back to my car and grabbed my camera even though I only had a wide angle lens that day. I was really surprised how far the little reptile had crawled by the time I got back. I almost didn’t find it because it didn’t leave any tracks. The other tortoises I’d encountered had easily tolerated my presence but I could tell the baby wasn’t going to get used to me, and I didn’t want to alert any birds, so I quickly left it alone.