Page 18 - Amphibian

Protection from predators

Amphibians have many enemies – each year millions are
eaten by other animals. Although most amphibians produce
poisonous chemicals in their skin, unlike snakes, spiders, and
scorpions they lack the means of inflicting a poisonous bite or
sting. An amphibian’s poison-defense (pp. 56–57) is usually
a last resort and will only work if a predator tries to eat it.
The main way in which an amphibian defends itself is
with camouflage, by remaining hidden and undetected
(pp. 20–21). If amphibians are disturbed, they will
sometimes use a startling behavior display to HIDE OR DAZZLE
frighten an enemy away, or give themselves The colorful fire-bellied toads
normally rely on their excellent
time to escape. camouflage (pp. 20–21) to stay hidden from
enemies. If faced by a predator, with no chance
POISONOUS NEWT of escape, the toad goes into a defense posture –
The red eft is the land- arching its back and showing the bright warning
dwelling, subadult stage of colors of its
the red-spotted newt of hands, feet,
eastern North America. It and belly.
spends two to three years on
land before it returns to
water as a fully adult newt.
Its red color tells predators
that it is poisonous and
distasteful to eat. Oriental
fire-bellied
toad
RED MIMIC
The bright northern red
salamander is a mimic – it
looks and behaves like the
poisonous red eft of the red-
spotted newt (above). In
this case the mimic is also
poisonous and benefits Yellow-
because predators have bellied
learned to avoid the more toad
common red-spotted newt. European (below)
fire-bellied
toad
Parotoid, or
poison, gland

POISON GLANDS
True toads, like the
European green toad,
have an enlarged
parotoid, or poison,
gland behind each
eye. If a toad is
threatened by a predator,
a poisonous, milky
secretion oozes from the
gland’s pores. When the gland
is pressed, the toad can squirt the
secretion for a short distance. If the
predator gets the poison in its eyes or mouth, it
suffers a burning sensation and muscle spasms,
causing heartbeat and breathing difficulties.