Desert Tortoise

Gopherus agassizii

Order: Testudines

Husbandry Information

Housing Requirements

  • Temperature, Humidity, & Lighting:
    • Temperature:
    • Humidity:
    • Lighting:
  • Substrate:

Diet Requirements

Veterinary Concerns

  • Zoo America: Upper respiratory infections tend to be a problem.

Notes on Enrichment & Training

Other

Colony or Breeding Management

Notes species is housed or managed socially or for breeding purposes.

Individual Identification

Dimorphism or practiced ways to individually mark species (such as those in colonies, like giant millipedes).

Programmatic Information

Transportation

Temperature Guidelines

 

Crating:

    • Brandywine Zoo: small reptiles travel in a Coleman “Party Stacker” type cooler that has been amended with extra ventilation holes on the lid (with a wood-burning tool). The cooler is lined with newspaper and, during cool weather (under 65°F), supplemental heat is provided with a hot water bottle (wrapped in newspaper)

    cooler     hot water bottle

Tips on Presentation

Touching Techniques

Tips on Handling

 

Potential Messaging

  • In general, animals seen at the zoo do not make good pets. Most have specialized dietary, veterinary, housing, and social needs that are difficult or impossible for even dedicated pet owners to meet. Always ensure that your future pet has not been taken from the wild. Capture of wild animals for the pet trade has significantly damaged the survival prospects of species such as sloths, tamanduas, and many parrots. Captured animals are typically mistreated by profit-motivated traffickers and dealers, resulting in many animal deaths; well-meaning animal lovers may feel like they are rescuing animals by purchasing them but are really perpetuating the cruelty. In addition, many exotic pets are released by their owners when they become too dangerous or demanding, often with devastating effects on local ecosystems. Animals that should never be kept as pets include all bats, primates, and exotic carnivores. Birds, fish, and reptiles have specialized needs, are frequently wild-caught, and damage the local environment if released; guests should be advised to educate themselves and proceed with caution. Domestic dogs and cats are almost always the best option! Many deserving animals are available for adoption at animal shelters. http://www.philadelphiazoo.org/Save-Wildlife/Images/PetWalletBro2012.aspxhttp://pin.primate.wisc.edu/aboutp/pets/index.html
  • Desert and Dryland species have specific adaptations for the temperature and water availability in their natural habitat and may not be able to adjust to the drying effects of climate change. Hotter conditions promote wildfires. More extreme drought conditions kill plants that hold the soil in place and occasional extreme rain events wash that soil away preventing them from growing back in a process called desertification. Greenhouse gas emissions from burning fossil fuels contributes to climate change by trapping heat in the atmosphere. Please ask guests to walk, bike, or take public transportation when possible and to reduce their use of fossil fuels when they do drive by buying a fuel economic car, carpooling, combining errands, and keeping vehicles properly tuned up and their tires properly inflated. At home and work, purchase Energy Star appliances, turn off lights when they are not in use, and use heaters and air conditioners sparingly. The principles of reduce, reuse, and recycle will also help by decreasing greenhouse gas emissions involved with the manufacture and disposal of unnecessary goods. http://www.unep.org/geo/gdoutlook/045.asphttp://www.epa.gov/climatechange/wycd/https://biomesfirst09.wikispaces.com/Desert+Conservationhttp://www.wildlifeadaptationstrategy.gov/pdf/Desert_Ecosystems_Paper.pdf

Acquisition Information

 

Comments from the Rating System

Natural History Information

Range and Habitat

Found in semi-arid grasslands, sandy or gravelly desert areas, canyon bottoms, and rocky hillsides in the Sonoran and Mojave deserts of southwestern United States and northern Mexico.

Physical Description

The desert tortoise is a medium-sized tortoise with a high-domed shell. The shell can be light or very dark brown, and the center of each scute is usually yellowish. The eyes are greenish-yellow. The skin is dry with enlarged, armor-like scales on exposed parts of the legs. Their legs are short and elephantine, and the front legs are flattened as an adaptation for digging. They have short, strong claws. Both sexes have a gular horn – an extension of the plastron below the neck. Males have a longer horn than females, and also have a longer, thicker tail. The male’s plastron is slightly concave. Adult desert tortoises grow to 11-16 inches in carapace length, and can weigh 10 pounds or more. Males are larger than females.

Life Cycle

Average life span in the wild is 25 to 35 years. Individuals have been documented to live 70 years.

Behavior

They dig burrows into sandy or gravelly soil, creating places where they can avoid the temperature extremes of the desert. Their burrows are sometimes just long enough to admit the tortoise, and rarely reach 30 feet in length. A single tortoise may dig more than a dozen burrows in its home range, and these are used by many other animals such as gopher frogs, hares, burrowing owls, snakes, and many insects. Desert tortoises spend the winters in their burrows, usually staying in torpor from November through February or March. In very dry areas, they may also enter torpor in the summer, when food is not available. During seasons when they are active, they feed in the early morning and late afternoon, spending cool nights and the hottest part of the days in their burrows.

During active periods, males use their gular horns to fight for dominance. By inserting the horn under the carapace of their opponent and twisting to one side, they can flip the opponent onto his back. In most fights, the subordinate male runs away before either tortoise is flipped over. During torpor or overnight, several males and females may gather together in a single burrow. Males do not appear to fight inside the burrows, although they may begin fighting as soon as they emerge each morning.

Threats and Conservation Status

Desert tortoises are listed as Threatened by USFWS; IUCN Red List – Vulnerable; CITES, appendix ll. Once widespread across the southwestern US, they are now only found in small, isolated populations. A key factor in their decline is habitat destruction, as desert areas are developed for agriculture or human habitation, or used to graze sheep and cattle. Desert tortoises are also captured for the pet trade, and many succumb to respiratory disease, which was probably introduced into the wild population by captive turtles that were released into the wild.

Did you know…

Photographs

Desert Tortoise

Documents

Any Documents to attach, species spotlights, etc.

Contributors and Citations

  • Lee Richardson Zoo
  • Houston Zoo, Natural Encounters