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Desert Tortoise. Gopherus agassizii. 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..). Basic Information.
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Desert Tortoise Gopherus agassizii
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..)
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 it’s delicious relative. ()
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)
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
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)
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.
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.
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 tortoise’s water intake comes from moisture in the vegetation they consume in the spring.
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.
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.
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.
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