the desert tortoise gopherus agassazii
Download
Skip this Video
Download Presentation
THE DESERT TORTOISE Gopherus agassazii

Loading in 2 Seconds...

play fullscreen
1 / 17

THE DESERT TORTOISE Gopherus agassazii - PowerPoint PPT Presentation


  • 240 Views
  • Uploaded on

THE DESERT TORTOISE Gopherus agassazii. By Karen Bernstein. Introduction. State reptile of Nevada & California The largest reptile in Mojave Desert K-selected species Endangered species Conflicting data about if & why endangered. Characteristics. Shell is yellow-brownish to dark brown

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'THE DESERT TORTOISE Gopherus agassazii' - MartaAdara


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
introduction
Introduction
  • State reptile of Nevada & California
  • The largest reptile in Mojave Desert
  • K-selected species
  • Endangered species
  • Conflicting data about if & why endangered
characteristics
Characteristics
  • Shell is yellow-brownish to dark brown
  • Shell averages 15-37 cm in length
  • Avg weight: male=20 kg, female=13 kg
habitat
Habitat
  • Found in NV, CA, UT, AZ & Mexico
  • Bajadas, alluvial fans, flats, & rocky terrain near scrub communities
  • Soil is determinant factor
  • Usually found between 1000-3000 feet
eating habits
Eating Habits
  • Herbivores
  • Diet largely depends on food availability
  • In spring, consume winter annuals
  • In summer, consume annual grasses (galleta grass)
reproduction
Reproduction
  • Mating period: March-June, Aug-Sept
  • Clutch size varies from 2-14 eggs
  • Incubation period highly variable
slide7
Hatchling success commonly < 60%
  • Reach sexual maturity between 14-20 years of age
  • Lifespan estimated 60-100 years
estivation hibernation
Estivation & Hibernation
  • Dig underground burrows
  • Summer burrows generally shorter than winter burrows
physiological ecology adaptations
Physiological Ecology & Adaptations
  • Do not maintain a daily internal homeostasis
  • Can tolerate large imbalances of water, energy, & salt
  • Mobile limbs & claws to dig burrows
  • Dig depressions in soil to catch rain
biogeography
Biogeography
  • 3 main populations: Sonoran Desert, Western Mojave Desert, & Eastern Mojave Desert
population trends
Population Trends
  • Tortoise population has dropped 90% in the last 50 years
  • US Fish & Wildlife has challenged these estimates
  • no concrete evidence to support the idea of a major reduction throughout their range
endangered species
Endangered Species
  • First listed as threatened in 1990
  • Need a permit to kill or collect them
environmental stresses
Environmental Stresses
  • Urbanization: habitat loss, vandalism, construction of roads
  • Off-Road Vehicles (ORVs)
  • Upper Respiratory Tract Disease (URTD)
  • Raven Predation
  • Grazing
  • Habitat Fragmentation
slide14
Source: http://www.cnn.com/EARTH/9704/23/tortoise/ Researchers voice hope for desert tortoiseFrom Correspondent Jim Hill
solutions
Solutions
  • Relocation Potential
  • Habitat Conservation Planning (HCPs)
  • Desert Tortoise National Area (DTNA)
slide16
Desert Tortoise in the Rain

His shell glistens with the moisture

of a early winter rain.

Small drops have drawn him

from his earth-dug bed

beneath porch steps-

all that remains of a house

washed away by fire.

The backyard fence,

which once kept him

from the sight ocean

or winding canyon,

has also been returned to ash.

The chirr of a wren

can now be heard

from camelia branches

which survived, somehow,

the red flow of flame

to hold new blossoms,

fluttering purple and red

as perfect as Chinese silk.

The tortoise, his head like a lump of lava,

takes one club foot step after another,

bumps his way across heaved red bricks.

He opens his mouth

to let his almost human tongue

loll out to lap up drops

of moisture dark as his eyes.

the end
The End

Thanks to Tom Stein!

ad