The Mojave Desert Tortoise is a species of tortoise that is native to the Mojave and Sonoran Deserts in the South-Western United States and North-Western Mexico.
This species of tortoise is often referred to simply as the Desert Tortoise for short. However, there are other ‘Desert’ tortoises so this can lead to confusion.
This is a medium to large sized tortoise that can grow to around a foot in length although this can vary by a couple of inches.
Mojave Desert Tortoise Taxonomy
In the Animal Kingdom, Taxonomy is used as the science and practice of classifying different species and sub-species based on their biological and genetic makeup.
Family
The Mojave Desert Tortoise belongs to the family Testudinidae. This is simply the family of tortoises. They are closely related to Pond Turtles and Asian Turtles.
Tortoises can vary greatly in size from the Galapagos Giant Tortoise that is over 1.2 metres to tiny tortoises that are only about 3 inches in length.
Most species of tortoise have a number of similarities. However, there are always a few exceptions to these rules.
In general, tortoises have a hard shell and they retract their head and neck directly backwards into the shell to protect them.
They are land animals that swim poorly or can’t swim at all. They typically move very slowly, with average speeds of less than 0.5km per hour.
There are 17 different genera of tortoises at the time of writing and over 60 recognised species.
Genus
The genus that the Mojave Desert Tortoise belongs to is called Gopherus. This is a genus of tortoise that are referred to as the Gopher Tortoises.
They are known as the Gopher Tortoises because they are fossorial. This means that they spend most of their life underground in burrows.
Some of the species in this genus dig burrows so large that they are often shared by other animals such as mammals, reptiles and birds.
There are currently 6 recognised species in this genus including the Texas Tortoise and the Gopher Tortoise.
Mojave Desert Tortoise Species
The scientific name for the Mojave Desert Tortoise is Gopherus agassizii. There are currently no recognised sub-species.
This tortoise was named after a Swiss-American zoologist named Jean Louis Rodolphe Agassiz.
Until 2011, the Morafka’s Desert Tortoise was considered to be the Mojave Desert Tortoise until DNA analysis got it elevated to full species status.
This separation severely reduced the range of the Gopherus agassizii in Mexico to the extreme North-Western portion of the country.
Mojave Desert Tortoise Description
The Mojave Desert Tortoise is a large species of tortoise that can grow to over a foot in length.
Most specimens typically fall within the range of between 10-14 inches. Males are typically larger than females.
These tortoises have a highly domed shell. The carapace or upper shell is brown, grey or black in color with lighter yellowish markings.
The plastron is lighter in color but still contains a mix of darker and light colors that have a washed-out appearance.
The skin of the Mojave Desert Tortoise is typically a brownish grey color while the scales of the feet are heavily keeled.
Natural Habitat and Distribution
The Mojave Desert Tortoise is native to the South-Western United States and a small part of North-Western Mexico.
In the United States, they can be found in parts of California, Nevada, Utah and Arizona. They like to live in very hot, arid environments.
In Mexico, their range is limited to a small area in the North-West in parts of Baja California and Sonora. They are found around the area of Mexicali.
This species credited with a much larger distribution in Mexico but the specimens further South were proven to be an entirely different species, the Morafka’s Desert Tortoise.
They can be found in a variety of different habitats such as arid sandy regions, rocky foothills and in canyons.
One of the most important factors that their habitat must possess is a suitable soil for them to make their burrows.
They share some of their range with species such as the California Mountain Kingsnake, the Ornate Box Turtle, the Sinaloan Milk Snake and the Rosy Boa.
Mojave Desert Tortoise Behaviour
The Mojave Desert Tortoise is an elusive animal that is rarely seen. This is because they spend around 90% of their life underground.
They will spend months at a time in their burrows and are typical only seen wandering around at certain times of the year while out foraging for food.
As can be expected, these tortoises are expert burrowers and will dig elaborate dens. They prefer certain types of soils to build these burrows.