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Exploring the beautiful nature of California
California Nature: Frogs
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Most amphibians have moist, smooth skin and are usually found in
wet environments, moving during rainfall, and in or near
standing or flowing water. Exceptions are toads and newts, which
can have rough or bumpy skin. And sometimes you will find
amphibians in dry areas, such as on roads at night, and even in
deserts with no obvious water nearby, either feeding, or moving
between wet areas.
Frogs and toads have four legs,
with enlarged rear legs, and no tail. An exception is the male
Tailed Frog, which appears to have a short tail, which is really
a reproductive organ.
They can be found during the day or at night, in water, and on
land, including climbing in bushes and trees and on roads at
night. Looking around ponds on warm sunny days is an excellent
way to find frogs.
Frogs are not usually confused with any other type of reptile or
amphibian, but frog larvae, or tadpoles, can be difficult to
tell apart from salamander larvae.
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At least 9 species of leopard frogs and several
close relatives are found in the Sonoran Desert
region. Differences among species are small and
often indistinguishable to the human eye. All
species are fairly large with pointed snouts,
webbed hind toes, long, powerful hind limbs, and
large external eardrums.
Leopard frogs are green or greenish brown with
creamy white undersides. The back, sides, and
legs are dotted with well-defined round dark
spots with a light border. Two distinct
light-colored glandular ridges run down the
back, from the eyes to the tail. There may also
be a light stripe on the upper jaw.
Leopard frogs are insectivorous and piscivorous
(fish-eating). Highly aquatic, they often jump
into water from the stream bank to avoid
capture. Leopard frogs may breed year-round, and
tadpoles may take more than a year to
metamorphose. Tadpoles get very large. These
frogs inhabit permanent and intermittent
streams, irrigation canals, and some ponds.
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The California Treefrog is a tiny frog of
desert canyons. It seeks shade during the day among jumbled
stones and boulders near water. Protective coloration helps
California Treefrogs avoid daytime predators. When disturbed, it
leaps into the water but returns almost immediately to shore.
During the dry summer months, California Treefrogs retreat deep
into crevices.
Found in southwestern California, the California Treefrog is a
warty, grayish treefrog between 1-2 inches, usually with round,
dark blotches on its skin. This frog's call is an often-repeated
quack. Males usually call while sitting in the water, often at
the base of a rock.
This is a species most likely to occur along streams with
abundant boulders and cobbles in their channels. Its
distribution is spotty and localized. These frogs are easily
handled.
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The Pacific Tree Frog is a very common species of chorus frog, with a range from the West Coast of the United States from North California, Oregon, and Washington to British Columbia in Canada. Living anywhere from sea level up to over 10,000 feet, they are found in shades of greens or browns and even have been known to change between them. They live in many types of habitats and reproduce in aquatic settings. This species is also known as the Pacific Chorus Frog. It is also the only frog that goes "ribbit"
One of the most interesting features of these frogs is their ability to change
color from brown to green. Previously, it was thought that there were two
different fixed colors that an adult tree frog could be. Now it has been found
that some of them are able to change between the two. They can also change from
lighter to darker, shift from patterned markings to pure colors and vice versa,
and even display combinations of colors, brown/green being the most frequent.These color changing morphs are triggered not by color change in their
environment, but a change in background brightness. This type of environmental
change would be caused by seasonal fluctuation. A full change in the dorsal
coloration of a color morph can take anywhere from weeks to months, but initial
changes can occur in just a few days. This has been shown to be a very useful
cryptic survival feature for these frogs. |
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Bullfrogs are widespread and very common. If you see a large brown and green frog (up to 8 inches long) in a permanent body of water just about anywhere in California except very high elevations, it is most likely a Bullfrog. Bullfrogs do not have a dorsolateral fold, but they do have a fold surrounding the eardrum.
Juveniles are much smaller, and are more common. One good way to identify juveniles is by the loud chirping sound they make as they jump from the shore into the water when you approach. Other frogs that occur with the Bullfrog do not make this sound.
This frog is rarely seen away from water, but you can sometimes find them on roads at night. Male Bullfrogs often call during the day, which may help you identify the frog.
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Frogs
Salamanders
Newts
Toads |
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