Desert Tortoise

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Desert Tortoise

• Gopherus agassizii

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Turtle or Tortoise?

• A tortoise dwells on the land with a high-domed
  shell.
• Elephant-shaped legs, and goes in the
  water only to drink or bathe.
• A turtle lives in the water (aka pond turtles,
  sea turtles,musk turtles etc..)

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Basic Information

• 8-15 lbs at sexual maturity
• 4-6 in height
• Lifespan is 80-100 years.
• One of three land dwelling turtles of the family
  Testudinidae
• Often mispronounced dessert tortoise, which is
  its delicious relative.
• (?)

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Tortoise Love

• Mating season is generally from August ? October,
  but mating can occur all year round.
• Male testosterone levels peak at this time.
• Females produce 4-8 white, hard-shelled eggs per
  clutch.
• 2-3 clutches per season.
• The temperature affects the gender of the
  tortoise
• Sexual maturity is not reached until 15-20 years
  (when the carapace is 7-8 inches)

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Delicious Treats Enjoyed by Tortoises

• Tortoises are herbivores
• Tortoises prefer native species of plants to
  invader species
• Also prefer perennials to annuals.
• Tortoises favor plant legumes to all above
  species of plants

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Habitat of Desert Tortoises

• Desert tortoises are adapted to live in
  deserts
• - Mojave Desert
• - Sonoran Deserts
• - southern Nevada,
• - south through Arizona into Mexico.
• Prefer rocky habitats (near alluvial fans, and
  around shrubs)

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Predators of Tortoises
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Endangered and Precious

• State animal of Nevada and California
• On the endangered species list
• Population of desert tortoises has declined over
  90 since the 1980s.
• Threats to the tortoises include
• Urbanization/habitat loss
• illegal collection (by humans)
• upper respiratory tract disease
• competition with cattle for food sources.
• It is unlawful to touch, harm, harass or collect
  desert tortoises.

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Tortoise Anatomy

• The upper shell is known as the carapace.
• Tough and scaly skin protects against water loss.
• The forelimbs are armored, muscular and used for
  burrowing (to make homes).
• The gular horn is used to overturn other males
  when fighting.

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Adaptations to Desert Life

• Cold blooded (internal temperature varies with
  outdoor temperature).
• Dig depressions with forelimbs to catch rain
• Large range in food that they eat.
• Most of the tortoises water intake comes from
  moisture in the vegetation they consume in the
  spring.

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Upper Respiratory Tract Disease

• Originated in captive tortoise populations.
• In 1988, wild tortoises in California were seen
  with puffy, recessed eyes, and a dull colored
  shell.
• More than 70 of adult males tortoises died from
  disease between 1988 and 1992.

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Curious Facts!!!

• 95 of the desert tortoises life is spent in
  underground burrows.
• May survive a year or more without access to
  water.
• Store water in a specialized urinary bladder so
  in times of drought water is available.

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For the Protection of the Tortoises

• Do not handle tortoises.
• Check under your vehicle before driving.
• Observe speed limits.
• Do not drive off-roading vehicles around wildlife
  preserves.

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References

• http//www.desertusa.com/june96/du_tort.html
• http//www.tortoise-tracks.org/gopherus.html
• http//www.nps.gov/archive/moja/mojaandt.htm
• National Geographic Encyclopedia of Animals