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DESERT RODENTS

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					DESERT RODENTS

     Size Doesn’t Matter
What is a Rodent Anyway?
   Rodentia comprises the
    single largest group of
    mammals (with the smallest
    members)
   The family Muridae contains
    over 1100 different species
    (rats, mice, voles, hamsters,
    etc.)
   Native on all continents
    except Antarctica
   Greatest diversity of form
    found in South America
    (isolated continent for most
    of the Cenozoic)
It’s all in the teeth
   Rodents all have a single pair of incisors
    in each jaw (grow continually through
    life)
   Thick enamel layers on the front but
    not on the back
   Large gap in the tooth rows (diastema),
    no canines, few molars.
   Large/complex jaw musculature
But Also Great Diversity…
   Most are herbivorous
    but some are
    omnivorous (eat insects
    too)
   Some diurnal, some
    nocturnal
   Can burrow, swim, or
    “fly”
   Can live solitary
    lifestyles or in highly
    social systems (like
    prairie dogs)
Castoroides
   Extinct giant beaver from the Pleistocene
    (about the size of a bear)
What is NOT a rodent
   Rabbits and bunnies!
    -They are lagomorphs (extra pair of incisors
    and different skeletal structure)
   Shrews, moles, and hedgehogs
    -Classified in the Insectivora
Ecosystem Function
   Reproduce rapidly
   Important food source
    for predators
   Valuable in seed
    dispersal
   Key disease vectors
    (population control,
    baby)
   Used by people for
    research, food, fur, and
    landmine detection
Desert Rodents
   All survive on very little water
    (specialized water retention)
   High daytime temperatures necessitate
    nocturnal habits
   Built for rapid locomotion in open
    spaces (super fast!)
   Pale colors take in less heat (and are
    good for camouflage)
Now Some Examples
Kangaroo Rat
   eats seeds and grasses
   hops on hind feet
    (using tail for balance)
   neither sweats nor
    pants
   “cute”
   communicates in
    “peeee’s,” growls,
    squeaks, squeals, and
    chuckles
Long-Tailed Pocket Mouse
   Does not drink free water. Gets water from
    green vegetation
   Feeds opportunistically on seeds, green
    vegetation and insects
Desert Woodrat
   Builds a house used
    for nesting, food
    catching, and
    predator escape
   Depends on prickly
    pear for water
   Rock outcrops, rocky
    cliffs and slopes
Mojave Round-tailed Ground
Squirrel
   Diurnal
   Hibernates in winter
    to avoid cold season
   Also sleeps through
    the hottest part of
    the summer
Antelope Squirrel
   Also Diurnal
   Only rodent active
    during the hottest
    part of the day in
    the summer months
And Everyone Wants to Eat Them
   Predators include the coyote, Mojave
    rattlesnake, mountain lion, bobcat, red-
    tailed hawk, golden eagle, barn owl, kit
    fox, badger (not a rodent) etc.
Tragedy in the Desert
Ah Rodents
   They   are   plentiful
   They   are   diverse
   They   are   highly evolved
   They   are   critical to ecosystem function
   They   are   cute and diseased
References
“Rodent.” Wikipedia. <http://en.wikipedia.org/wiki/Rodent>
“Introduction to Rodentia.”
    http://www.ucmp.berkeley.edu/mammal/rodentia/rodentia.html
Hafner, Mark S. “Density and Diversity in Mojave Desert Rodent and Shrub
    Communities.” Journal of Animal Ecology: (1977), Vol. 46,925-938.
“Kangaroo Rats.” Desert USA.
    http://www.desertusa.com/aug96/du_krat.html
“Desert Animal Survival.” Desert USA.
    http://www.desertusa.com/survive.html
California Department of Fish and Game. “California Wildlife Habitat
    Relationship System.” Database Version 8.1. (2005).

				
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