Defense
Compared to other vertebrates,
which may be faster and stronger or possess poisonous bites or sharp
claws, amphibians are relatively easy prey. In water and on land, they
are pursued by a hungry throng of birds, mammals, reptiles, fishes, and
other amphibians. Yet they have managed to survive for millions of
years.
Amphibian Armor
Amphibians don’t have fangs and talons, but their subtle defense systems
still function well. They have relatively small, slippery bodies and a
generally quiet and retiring nature. Many species don’t show themselves
in daylight. Amphibians also have other survival tricks, many involving
coloration.
Flashing
Flash coloration is different from warning coloration because it
is not seen until the amphibian is under attack. The bright
colors distract and confuse predators and help the amphibians
escape.
Poisons
Many amphibians produce mild skin poisons, and some secretions
are toxic enough to kill predators. In salamanders, the tail is
often the most poisonous part (and the part predators can most
easily grab).
Other Tricks
Imitating poisonous species can help keep salamanders alive. Some use
the old trick of playing dead. Others protect themselves by biting.
Sirens even scream and yelp. One unusual defense is the ability to
survive, at least for a while, in the stomach of a predator. Poisonous
Red Efts can live there up to 30 minutes, by which time they have
usually been spit up by whatever swallowed them.
Color-change Artists
Changing skin coloration is employed by frogs, toads, and some
salamanders. Treefrogs and other color-change artists change
their colors over time to match the background they rest upon.
Standing Out
Warning coloration is the opposite of protective coloration.
Bright colors on the upper surface of the skin usually mean the
amphibian has quite poisonous skin. Predators who attack a
brightly colored amphibian quickly learn to avoid
similar-looking ones in the future.
Blending In
Protective coloration is important to many amphibians, a large
number of which are green, brown, or gray—colors that are common
in nature. These color patterns act as camouflage, helping
amphibians blend in with their surroundings.
