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Mojave desert tortoise
Gopherus agassizii
An iconic terrestrial tortoise native to the Mojave Desert of the United States, highly adapted to extreme arid conditions and protected under U.S. federal laws.
Class:Testudines
Order:Testudines
Family:Testudinidae
Genus:Gopherus
Species:Gopherus agassizii
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Environment
Terrestrial
Humidity
30 - 50 %
Day temperature
12 - 34 °C
Ambient temperature
12 - 34 °C
Night temperature
21 - 23 °C
Basking spot
32 - 35 °C
Adult size
36 cm
Minimum enclosure
>= 800 L
Brumation temperature
5 - 10 °C
UVB
High
Species description
Geographical Origin and Habitat: Gopherus agassizii, commonly known as the Mojave desert tortoise, is native to the desert regions of the southwestern United States, primarily within the Mojave and Colorado Deserts of southern California, southern Nevada, southwestern Utah, and western Arizona. It inhabits sandy flats, alluvial fans (bajadas), rocky hillsides, and desert canyons. Its natural habitat is characterized by extreme temperature fluctuations, ranging from sub-freezing winters to scorching summers, where creosote bush (Larrea tridentata) scrub dominates and provides crucial cover.
Taxonomy and Genetics: It belongs to the family Testudinidae. Previously classified as the same species as the Sonoran desert tortoise (Gopherus morafkai), detailed mitochondrial DNA analysis and morphological studies confirmed Gopherus agassizii as a distinct species, separated geographically by the Colorado River. It is listed as a threatened species under the U.S. Endangered Species Act. Conservation genetic programs are actively managed to monitor population fragmentation and prevent genetic bottlenecks.
Behavior and Habits: Diurnal and crepuscular, adapting its active hours depending on seasonal temperatures. To survive the extreme desert heat of summer (exceeding 45°C) and the freezing temperatures of winter, it excavates deep, extensive burrows that can reach up to 9 meters in length. It spends over 95% of its life underground within these thermal shelters. It enters a state of deep brumation during the winter months and may estivate during dry summer periods to conserve body water.
Morphology: It possesses a highly domed carapace that varies in color from brown and gray to dark yellow-orange, featuring distinct growth rings on the scutes. Adults typically reach a carapace length of 25 to 37 cm. The forelimbs are heavily scaled, flattened, and equipped with thick claws designed for heavy digging. The hind limbs are elephantine and cylindrical. Adult males are distinguished by a concave plastron and a long, upturned gular horn used to flip rivals during combat.
Care, breeding and tankmates
Terrarium Setup: Keeping this species indoors is only suitable for hatchlings or sick individuals, requiring a minimum enclosure size of 250-300 liters. Adults must be kept in large, secure outdoor pens that replicate their arid desert habitat. The substrate must consist of a deep, dry mix of topsoil and silica sand (50:50 ratio) that allows natural digging behavior. Provide sturdy, stable rock shelters and hollow logs that will not collapse.
Lighting and Heating: A strong thermal gradient is essential for indoor setups. Maintain a cool side at 24-26°C and a basking spot of 32-35°C using overhead basking lamps. A night drop to 18-20°C is required. High-output UVB lighting (10.0 or higher) must be provided for 12 hours daily, mounted at a safe distance to ensure sufficient UV radiation without risking thermal injury.
Humidity and Hydration: Maintain a dry overall environment with relative humidity between 30% and 50%. However, micro-humidity inside the burrows should be slightly higher. Provide a very shallow, wide water bowl for drinking and soaking, ensuring the water level does not exceed the bridge of the shell to prevent drowning. Change the water daily.
Feeding and Supplementation: Their diet must be strictly herbivorous, high in fiber, and very low in proteins and sugars. Feed a variety of wild desert grasses, weeds, dandelions, clover, hibiscus leaves, grass hay, and spineless prickly pear cactus pads (Opuntia). Never feed commercial canned foods or fruit. Dust food with calcium carbonate three times a week and vitamin D3 once a week.
Compatibility: Adult males are highly territorial and combative, especially during the breeding season. They must never be housed together to prevent fighting, which can result in injuries or a tortoise being flipped onto its back. A single male can be kept with one or two females in a very large outdoor pen with ample visual barriers.
Health and Common Diseases: Highly susceptible to Upper Respiratory Tract Disease (URTD), primarily caused by Mycoplasma, which is contagious and can be fatal. Poor lighting or diet leads to Metabolic Bone Disease (MBD) and shell pyramiding. Consult an experienced reptile veterinarian for any health concerns or quarantine protocols.
Geographic Origin and Distribution
Gopherus agassizii, commonly known as the Mojave desert tortoise, is native to the desert regions of the southwestern United States, primarily within the Mojave and Colorado Deserts of southern California, southern Nevada, southwestern Utah, and western Arizona. It inhabits sandy flats, alluvial fans (bajadas), rocky hillsides, and desert canyons. Its natural habitat is characterized by extreme temperature fluctuations, ranging from sub-freezing winters to scorching summers, where creosote bush (Larrea tridentata) scrub dominates and provides crucial cover.
Origin
North America
Reptile profile
- Diet
- No verified data available
- Life expectancy
- No verified data available
- Adult size
- 36 cm
- Lifestyle/Microhabitat
- No verified data available
- Activity cycle
- No verified data available
- Sociality
- No verified data available
- Reproduction
- No verified data available
- Handling tolerance
- No verified data available
- Brumation
- No verified data available
- Molting
- No verified data available
The catalog's scalar value is 36 cm. The ReptTraits v1.2 source reports a maximum adult measurement of 36 cm for this species, recorded as straight carapace length (SCL). These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
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