| Common Name: | Desert tortoise |
| Scientific Name: | Gopherus agassizii and Gopherus morafkai |
| Life Span: | More than 20 years |
| Size: | 8 to 10 pounds for adults |
| Habitat: | Creosote bushes, grasslands with alluvial plains, and yucca trees |
| Country of Origin: | Southwestern United States to Northwestern Mexico |
Scientific Facts
Physical Description
The desert tortoise is a medium-sized tortoise species living in the South-western desert areas of Northern America and some portions of Northern Mexico. This kind of tortoise became widely known due to its high patterned shell, aside from the fact that it lives in an underground burrow.
Typically, a desert tortoise grows up to 14 inches long. The hatchlings are mostly 2 to 2 ½ inches long. When it comes to height, it stands from 4 to 6 inches from the floor.
Its upper shell or carapace has a distinct high-domed and circular appearance. It measures 9 to 15 inches long. The head of a desert tortoise is relatively narrow. Its upper jaw edges meet at the angular point.
Also, the eye rings of this animal are light. The iris can be greenish-yellow or yellowish. The beak of a desert tortoise protrudes out like other tortoises. The animal uses its beak in tearing the food.
Both male and female desert tortoises come with a gular horn that serves as the anterior extension of their lower shell. However, the gular horn of a male desert tortoise is larger and upturned. Every desert tortoise uses this horn in protection itself, especially when males are fighting during the mating season.
Also, a desert tortoise has a shorter tail. However, it comes with solid hind limbs, which are heavy and with 4 digits. The flat forelimbs are shovel-like with 5 digits.
Unlike other tortoises, a desert tortoise does not have webbed feet. Instead, its feet are wrapped with huge cone-shaped scales.
In general, a male desert tortoise is bigger than a female. To spot a female desert tortoise, look for the flat plastron in the lower shell that extends at the back.
Types
A desert tortoise can be classified into two: Gopherus agassizii and Gopherus morafkai. G. agassizii has been distributed in southeastern California, western Arizona, southern Utah, and southern Nevada. Its name “agassizii” is in honor of Jean Louis Rodolphe Agassiz, a Swiss-American zoologist.
In 2011, the researchers revealed that a desert tortoise exists in two species based on geographic, DNA, and behavioral differences. Today, a desert tortoise can be a Gopherus agassizii or Gopherus morafkai. G. morafkai originated in the east part of Colorado River in Arizona and the states of Sinaloa and Sonora in Mexico.
The new species name is also in honor of the late David Joseph Morafka, a professor of California State University in Dominguez Hills. This is to recognize his contributions to the research and conversation of the desert tortoise.
Life Span
On average, a desert tortoise can live for more than 2 decades. In most cases, it can reach the age of 35. However, there have been records showing that some of them had lived for 50 to even 100 years. A female desert tortoise often has a shorter life span than a male.
Habitat
The desert scrubs, foothills, thorn scrubs, and tropical deciduous forests are the most common natural habitats for a desert tortoise. Although, many of them prefer to live in the creosote bush scrub at 1,000 to 3,000 ft. above sea level.
Diet
The desert tortoise is an herbivore. It loves to eat a variety of plants in the forests. In captivity, the best diet for this animal includes a range of foods that meet its nutritional requirements to stay healthy and happy. Ideally, a captive tortoise must be able to graze on the grasses, flowers, and leafy plants.
Grass contributes a lot to your pet’s diet if you create a patch that is big enough. The one measuring 6 feet x 6 feet will be enough. Other plants that you can give to a desert tortoise include dichondra, native grasses, filaree, dandelion, spurge, hibiscus, mulberry, wild grape, and wildflowers like the globemallow. Your pet will enjoy the stems, leaves, and flowers of those plants.
Commercially produced foods for a desert tortoise are typically less nutritious than the organic plants mentioned above, mainly due to their lower fiber and higher water content. However, commercial produce can serve as the supplemental source of food if you can’t establish plants in the enclosure.
Dark green plants that are rich in vitamins and minerals like kale, collard, mustard greens, cilantro, turnip greens, and parsley can be the best short-term alternatives.
In giving acceptable produce and dark greens, make sure they are fresh, clean, and sliced into small pieces. Don’t feed your pet with iceberg lettuce as it contains fewer nutrients.
Also, you have to serve the foods on a feeding platform or dish to avoid ingestion of sand and gravel that can trigger gastrointestinal impaction or irritation.
Many tortoises eat unhealthy foods. These animals may look healthy for a long time despite having a poor diet. Foods that are high in sugars, such as fruits, animal fats, or protein will damage the functioning of the vital organs that can lead the tortoise to death.
Don’t feed your pet with cat or dog food, monkey chow, and any other food containing protein more than 15%. This will lead to kidney or liver damage and malformed shell growth.
Also, avoid giving sodium-rich foods or frozen vegetables, including dairy products, canned veggies, celery, and bread. Most importantly, keep your pet safe from toxic plants like chinaberry trees, oleander, toadstools, and tree tobacco.
To keep your pet healthy and active, be careful when you feed it. Always make sure that everything you give is nutritious and safe for a desert tortoise. If you are not sure, always seek advice from a professional desert tortoise breeder.
Moreover, the desert tortoise may also love fruits, but you should give them just when your pet deserves a treat. You can give fruits once a month or so. Give a tiny piece of fruit like a strawberry or a quarter slice of skinned watermelon.
Fruits can be nutritious, but they contain excess sugar and water. So, just give it to your pet in moderation. Starch and sugar disrupt digestion as it changes the bacteria living in the animal’s hindgut.
Likewise, make sure that water is always available within the enclosure. Change it a few days every week. Keep your water dish in a similar place so that your pet knows where it is. The desert tortoise depends on the food for its water needs, so you will not see your pet drinking frequently.
However, a desert tortoise enjoys soaking occasionally. Therefore, make sure your pet’s water dish is wide and deep enough for that purpose.
Hibernation
Since the desert tortoise lives in a desert, it’s not easy for it to have a consistent water supply or even getting exposed to moisture. Thus, the animal lives a torpid or dormant life of hibernation from late October until November or even February.
When hibernating, the desert tortoise typically lives inside the burrow to avoid losing the water in its body. Hibernation is also a way for this tortoise to stay protected from the burning heat of the summer season or the shivering cold during winter. When your pet enters this period, its heart rate, breathing, and other bodily processes will slow down.
You can help your pet undergo the hibernation process in various ways. Some areas with well-draining soils and of the desert kind allow the desert tortoise to hibernate outdoors in a burrow. If you’re okay with this, then just be sure the burrow is safe from the flood.
The other option is to use a dog loo or doghouse filled with straw and grasses. Again, be sure the animal stays dry within. Grasses and straw are prone to mold when wet, so check it when days and nights are damp, foggy, or rainy.
When using these housing methods, make sure they’re placed in the cool and shady areas far from direct sunlight to preserve the cool temperature. Likewise, make sure these areas are safe from predators like skunks, raccoons, rats, and coyotes.
Lifestyle and Behavior
The desert tortoise spends nearly 98% of its time underground. It tends to be most active during the rainy season and springtime to hunt for food. Male-to-male aggression is somewhat common, which happens more often during the mating season. A larger male desert tortoise dominates over the small one. During the breeding period, the male tortoise may show tumble and rough behavior. It may even use its gular horn in flipping and defeating the opponent.
What’s more interesting about the desert tortoise is that it can store water in its body. The animal recycles that water throughout those dry, hot summer months. Most of the water in its body came from the flowers and grasses it consumed during the springtime.
These tortoises show various body movements such as chin gland sniffing, circling to the other tortoise, biting, and head-bobbing. These moves are especially for exchanging pleasantries, courtship, and inter-species sociable behavior.
A Burrow Builder
The desert tortoise is good at creating burrows. During the summer season, the temperatures of the soil surface can go as high as 140 degrees Fahrenheit. To escape the heat, the desert tortoise uses its strong forearms and nails to excavate and make burrows where it can hide from the burning sun rays.
This animal can make burrows that are up to 32 feet long. These holes can even become quite crowded throughout the summer season. Each burrow of that size can accommodate up to 25 tortoises.
Also, a desert tortoise digs grooves into the soil surface to collect rainwater. After the storm, it comes back to the holes and drinks the available rainwater. Once the desert tortoise gets the right amount of water it can store, it can move on and spend the rest of the year without feeling thirsty. The animal stores the water it drank in its bladder. When it needs to hydrate, the accumulated water in the bladder will simply return and circulate again throughout the body, making the desert tortoise feeling refreshed and energized.
Common Health Problems
The desert tortoise is subject to different diseases. These health issues are often due to opportunistic pathogens and parasites that attack a weak tortoise. These microorganisms cause disease when the animal is sick due to malnutrition, stress, and incorrect physical environment.
Preventing these diseases is possible to achieve by giving the necessary physical environment, caging features, and proper diet. All those things depend on the pet owner – you.
Respiratory Infections
These are the most common health issues associated with this reptile. Many experts say that the main culprit of these diseases is highly infectious viruses. Sometimes, a desert tortoise looks physically healthy, but in truth, it’s a disease carrier that can transmit the infection to any susceptible tortoise.
Once infected, the tortoise will manifest the symptoms of a minor upper respiratory disease like a runny nose. In worse cases, the animal suffers from serious systemic complications affecting the liver, kidneys, heart, and other vital organs, including the complications related to blood parasite diseases.
The desert tortoise is defenseless and extremely vulnerable to diseases. It may also struggle in combating the effects of a devastating disease or infection. There’s no specific treatment for respiratory diseases associated with this animal.
Therefore, you should bring your pet to a licensed veterinarian as soon as you notice any signs of respiratory disease. The sick animal needs thorough evaluation and close observation to know the most suitable treatment for its condition.
The assessment must entail the survey blood profile and antibiotic and culture sensitivity testing. The treatment for an infected tortoise is symptomatic and will emphasize supportive care such as vitamin injections, nasal flushes, fluid therapy, force-feeding, and immune-stimulating medicines. The topical antibiotics and antibiotic injections for sinuses and eyes are so important to prevent and treat secondary bacterial infections.
As a pet owner, you have to be more responsible in ensuring the health of your desert tortoise. If your pet is new, bring to a veterinarian for health assessment and quarantine that will last for 6 weeks. If the animal shows any symptoms of respiratory disease, then it should be separated from others for a while. If it recovers, the animal may remain as a carrier of the disease for the rest of its life.
Internal Infections
A wide array of bacterial infections can take place to a captive desert tortoise. These health issues affect different organs. Kidney and liver diseases such as chronic kidney disease and chronic hepatitis are more common due to the septic nature of those diseases and the filtering functions of these organs.
Mouth Rot or Infectious Stomatitis
This issue can be exactly the outcome of a mouth and lining injury or a complication of any other disease somewhere in your pet’s body. Mouth rot must be treated topically and systematically for internal abscess prevention. Jaw and beak deformation might require intermittent corrective trimming.
Another common health issue affecting the desert tortoise is a vitamin deficiency that can come in many forms. For instance, your pet may show the signs of vitamin A deficiency like nasal discharge and swollen eyelids.
Vitamin deficiency of any form is preventable by just giving the ideal diet for the animal. Fat-soluble vitamins are not good for a tortoise. Therefore, you must avoid giving them to your pet unless recommended by the veterinarian.
Do those eyes look sunken? Sunken eyes may signify dehydration. Swollen body tissues and liquid or pasty feces may indicate infection or malnutrition. Prolonged activity and tendency to keep its eyes closed might mean the animal is sick. However, a tortoise is normally inactive throughout the winter hibernation and dry, hot summer aestivation.
A sick tortoise usually refuses to eat and becomes emaciated. In that case, the animal should receive immediate care and assistance. If the veterinarian sees it abnormally light, it might have emaciation and dehydration. If the animal is too heavy, then it may have stones in the bladder. To be healthy, its head and legs must look symmetrical while the bones must not look too prominent.
Adaptations
A desert tortoise can live without water for more than one year. its shells are high-domed with ample space for its lungs. It can effectively carry on through thermoregulation in the heat of waterless deserts.
The female desert tortoise uses the hind limbs in digging and making a nest. It can tolerate high urea levels in its blood. For that, it can resist excess urine, thereby losing moisture or water from its body.
Since this type of tortoise is not a water creature, its burrowing habit is an adaptation. Living in a burrow mitigates the impact of desert heat and moisture extremes. At the same time, it’s one way of keeping the desert tortoise itself from predators.
Also, this tortoise is adapted to making holes in the soil that will catch and collect rainwater, which is so rare in the desert.
Predators
A desert tortoise can also become food for bigger animals. These predators may vary depending on the victim’s size, age, and habitat. Coyotes, kit fox, badger, and Gila monsters attack the eggs. The young tortoises are victims of some snakes, bobcats, ravens, roadrunners, badgers, coyotes, spotted skunk, and kit foxes.
Big tortoises can fight predation. However, they can still be preyed by badgers, bobcats, golden eagles, coyotes, and kit foxes.
Big mammals typically attack them just when there’s a scarcity of other sources of food like rodents and rabbits.
Courtship and Mating
Courtship and mating among desert tortoises happen in spring and summer. The male nods its head at the female while he approaches. It was usually circling the female before trying to mate. The female tortoise will typically snub the male but becomes interested in the male’s courting attitude.
Copulation could be extremely brief, or it may last for hours. Both genders can mate with other tortoises throughout the breeding season. Fighting between the male desert tortoises might happen wherein the males ram one another. At times, a male tortoise flips over the other, causing it to suffer internal damage and die only when it fails to flip itself back as quick as it can.
Incubation and Eggs
The female tortoises will lay their eggs in July soon before or after the first summer rain. They can lay fertile eggs up to 4 years with just one mating by retaining the sperm. In these cases, the number of fertile eggs for every clutch will reduce with time.
When it needs to lay the eggs, the tortoise will make a hole under the ground. Usually, a clutch contains 2 to 14 eggs. The age and size of a female desert tortoise is a determining factor for the clutch size.
After laying the eggs, the tortoise will fill in the hole. It may even protect the nest hole sometimes against the predators, though it doesn’t care for the babies. Hatchlings will come out between 80 and 120 days after the mother laid the eggs. The hatchlings will crack the eggshells with a momentary protrusion on the upper jaw known as the egg tooth, which disappears sooner after hatching.
Alternating between the periods of rest and activity, the hatchlings will emerge from the eggshells and dig their way to the surface. The hatchlings are about the circumference of a silver dollar. Their shells are somewhat pliable, and some yolk can still ben lingering to the plastron. The hatchlings might take 1 to 2 days to leave the eggshells.
Distribution
Desert tortoises are widely spread all over the Sonoran Desert and Mojave Desert of Northwest Mexico and Southwest US. They also exist in the Sinaloan thornscrub, southeastern California, western Arizona, southwestern Utah, and southern Nevada.
Ecosystem Role
The desert tortoise is a primary consumer and becomes prey for different avian, mammalian, and reptile predators. It also acts as an ecosystem engineer that digs burrows used as shelters by snakes, birds, lizards, rodents, javelinas, and insects.
This reptile takes advantage of the packrat houses for shelter. In a study, researchers found that desert tortoises were living with a big colony of Africanized honeybees. It’s a strong and effective defense against the predators. Finally, the desert tortoise has some external parasites, but it can also be a host to duodenal pinworms.
Economic Significance for Humans
Before, the indigenous people in Southwest America used the desert tortoises for medicine and food. They used their shells in making bowls, shovels, and ladles. These animals were central figures within the region’s folklore. Still, these animals are used for food in some areas in Mexico.
In Arizona, more and more people started keeping desert tortoises as pets. As of now, there were no reported bad effects of desert tortoises on people.
Housing
The desert tortoise thrives well if you keep it outdoors as it gives a much more comfortable and appropriate environment, including:
- UVB rays from the sun
- Natural ability to self-regulate temperature
- Natural forage of foodstuffs
These things are hard to provide to them indoors. However, if the outdoor accommodations are impractical, not safe from predators, and environmentally unsuitable, indoor facilities might become necessary.
Some type of predator-proof outdoor housing, particularly during the summer, is better than the indoor kind. Since a desert tortoise loves to burrow, the walls must be sunk well underneath the surface. At the same time, it must be at least 1 ½ times higher because these animals are long.
They are not okay with heavy rainfalls and high humidity. If these conditions prevail, care should be provided. A large part of their habitat should stay dry by using proper landscaping or giving proper drainage.
Don’t allow the water to stand within the enclosure. Instead, use the sprinklers when giving water to tortoises. Do it once or twice every week and let the animals drink. This will naturally trigger them to excrete the old water stored in their bladders and replace it with the freshly provided.
Caging
Experts recommend keeping the desert tortoise outdoors as much as possible. You can make pens with solid and sturdy walls where your pet can’t see through. Tortoises would try hopelessly to walk over the fences if you leave the sides uncovered. The walls must extend under the ground surface for at least 6 to 12 inches to discourage your pet from excavating underneath the walls. Also, the enclosure should give the tortoise protection against the predators and other pets you have like dogs that can harm it.
Indoor housing is appropriate only for sick and small tortoises. The young tortoises must be housed in the enclosures with the opaque sides for a similar reason. Solid fencing is highly suitable for outdoor pens.
Commercially available enclosures for tortoises work well. On the other hand, a large and wide storage container can also be an alternative. When choosing the best enclosure for your pet, you should consider the following:
Cage Size
An outdoor enclosure must be minimally 18 sq. ft. in size for the adult tortoise.
Substrate
Natural soil outdoors and compacted natural topsoil are advisable. Alternatively, you can use a combination of coconut fiber sheet and cypress mulch. Don’t use reptile banks, sand, wood shavings, and gravel as your pet may ingest them by accident. Also, they may get covered with dust that can trigger respiratory irritation. You can use rabbit pellets but be careful because it is very susceptible to mold. Substrates must be at least 3 to 5 inches deep or more to let the tortoise burrow.
Cage Furnishings
A shelter must be provided like a cave or hide when keeping a desert tortoise indoors. You can also use artificial burrows when keeping it outdoors. If water is available, use a wide and shallow dish that is big enough so that your pet can fully climb within.
You can also give it water by flooding a part of the pen. Or, you can put a bowl with warm water and soak the tortoise in it for 15 to 30 minutes. Do it several times a week. However, it is much better not to give water to your pet from time to time. Intermittent water availability will encourage it to drink well, and empty the bladder fully, refilling it with fresh water. Also, don’t forget to use a patio stone or flat dish to prevent your tortoise from ingesting the substrate when giving it food.
Temperature
In the daytime, the temperature should be between 85 to 88 degrees Fahrenheit. At night, it should be anywhere between 75 and 80 degrees Fahrenheit. When it basks, the temperature should stay between 95 and 100 degrees Fahrenheit.
When taking care of a desert tortoise indoors, be sure you give it a heat lamp to maintain the ideal temperature inside the enclosure. Put the lamp off to a side of the cage to form a temperature gradient. Use a thermostat and a thermometer to ensure the temperature is within the recommended range.
Lighting
If you keep the tortoise indoors, then the enclosure should have artificial UVB lights that can help its body absorb the calcium content of every food you gave to it. You can use a fluorescent or mercury vapor reptile light designed for this purpose. Follow the instructions provided by the manufacturer regarding bulb placement.
Generally, the bulbs require the tortoise to get into the covered space for ample UVB exposure. This area usually measures 12 to 18 inches. Replace the bulbs every 6 to 12 months, but this may still depend on the recommendations of the manufacturer. These bulbs will stop emitting UVB light sooner before they halt producing visible light.
However, if you prefer keeping your pet outdoors, you don’t need to provide it with UVB lights. Instead, it will depend on the sun for the needed exposure to UVB light.
Cleaning and Disinfection
For an indoor enclosure, you can eliminate the droppings but minimally each day. Replace the substrate once or twice every month. Do it more often if necessary. Use a freshly made diluted bleach solution when cleaning the furnishings and enclosure at least once in a month by.
After that, rinse well the enclosure to remove dirt and the used disinfectant. Make sure the enclosure is clean and smell-free. Put the cleaned enclosure under the sun to make it more sterilized.
For an outdoor enclosure, keep it clean and remove the feces as often as you can. Clean the water bowl and sanitize it every 2 to 4 weeks.
Safety
Your desert tortoise should not gain access to spas, swimming pools, stairs, and ponds. If you own a young tortoise and you have a cat, protect it from your other pet.
A male tortoise should be separated from other males. If not, they may fight against each other. Sometimes, a male could be too aggressive even if you put it together with a female tortoise.
Availability – Where to Get One?
For some people, the desert tortoise can be good pets. With the Tortoise Adoption Program, one can adopt a captive desert tortoise and be its caregiver. The tortoises can’t be obtained from the forest. Instead, they should come from another “adopter” through this program.
The desert tortoise is an endangered species. In California, people who want to own a desert tortoise should secure a special permit. The US federal and state laws do not allow anyone to buy or sell this animal.
How to Care for a Desert Tortoise?
Your pet will need a big outdoor space with ample space for its digging habit. Also, it should have quick access to water and vegetation. Also, it should have a den as a safe shelter.
Pay attention to your pet’s diet. Give it nutritious foods rich in vitamins and minerals for growth and strong immunity.
Fun Facts about Desert Tortoise
- The shell of a desert tortoise has protruding growth lines on the shields of the upper and lower shells.
- The top shell of this tortoise is brown while the bottom is yellow.
- The female desert tortoise can lay eggs for years even with just single mating.
- The desert tortoise remains inactive most of the time.
- It stays more often in a burrow or rock shelters to lessen water loss and regulate its body temperature.
- The front legs of a desert tortoise have rough scales that make it invulnerable.
FAQ
What temperature is too cold for desert tortoises?
Anything below 50 degrees Fahrenheit or 10 degrees Celsius is too cold for the desert tortoise. The case, however, is different during the hibernation period, when you need to closely monitor and regulate the temperature for your pet.
How much does the desert tortoise eat?
The desert tortoise needs around 20 to 30 days to digest the consumed food. It will spread the seeds from its meals across its enclosure as it poops.
Are desert tortoises aggressive?
The desert tortoise does not show aggression to humans, except when you hurt them. It likes to live on its own, but it will look for a company during the breeding season.
Do desert tortoises love being touched?
Tortoises, including the desert tortoises, can feel your hands touching their shells. You can rub, pet, and scratch their neck, which they enjoy.
Do desert tortoises bite humans?
The desert tortoises may bite humans to defend themselves when feeling threatened. They bite using their beaks, which can be painful and may cause bacterial infection when left untreated.
