Startling a Predator
|A flash of the red-eyed tree frog’s large red eyes can
and give it time to escape.
Anyone who has jumped when startled knows how a predator
might feel when its prey suddenly bursts into motion after being
nearly invisible. The shock of the prey’s sudden reappearance is enough to make a predator flinch or pause for a fraction of a second.
That little bit of extra time can let an animal escape with
A variety of animals even sport special colors or body parts
to help them startle predators. These colors and parts are used in
behaviors called startle displays
. A startle display may be used
to fend off an attack right from the start. Many startle displays of
this type involve suddenly flashing a vivid color or pattern.
This is the tactic used by the io moth, which lives in North
America. At rest, an io moth is pale yellow or brown. But if a bird
attempts to grab it, the io moth quickly moves its forewings. This
reveals two hind wings boldly colored with a pair of big black
spots surrounded by a circle of yellow. These spots look like eyes,
and are called eyespots
. To a bird, the display of eyespots may
look like the sudden appearance of a larger bird, such as an owl—
its own predator. The startled bird may fly away rather than risk
its life, or it may pause long enough for the moth to escape.
Eyespots are found on the wings of hundreds of species of
moths and butterflies. They are also seen on many caterpillars.
A swallowtail butterfly’s plump green body has two huge yellow
eyespots on its humped front end. This makes it look like a
snake. When threatened, the vine hawk moth’s brown caterpillar
curls into a “C” and bulges its yellow eyespots. A Malaysian
hawk moth caterpillar puffs up its front end when threatened.
This makes its eyespots open wide. It also snaps its head back and
forth as if it were a snake about to strike.
Other insects flash startling eyespots, too. The African
flower mantis, which usually blends in with the shapes and colors
of its flowery habitat, flares out wings with eyespots when it is
threatened. The eyed click beetle has two black eyespots behind
its head. An Australian moth caterpillar has eyespots that are
normally hidden in the folds of its body. When it flexes its hind
end, the folds open like lids to reveal the “eyes.”
Patches of color that do not look like eyes also make effective
startle displays. These colors are often hidden until an animal
flees. The sudden appearance of this flash coloration
can stop a
predator in its tracks just long enough to let the prey escape.
A red-eyed tree frog, for example, usually blends in with the
leaf on which it sleeps. If a predator bothers it, the frog first pops
open its enormous red eyes. Then it leaps away, turning from a
plain green frog into a rainbow of color as its orange-footed legs
unfold and its blue and yellow sides appear. This sudden splash of
color startles the predator and buys the frog time to get away.
Octopuses also abruptly give up on camouflage when they
are under attack. An alarmed octopus can burst into startling
colors or patterns in less than a second. A fish or turtle that sees its intended meal suddenly turn black or zebra-striped is often
Many kinds of stick insects, grasshoppers, butterflies, moths,
and other insects also flash bright colors when fleeing a predator.
The colors disappear when they leap or fly to a new spot and fold
their wings. They then blend in with their surroundings as they
sit perfectly still.
Sometimes just a spot of color can do the trick. The shingleback
skink of Australia is a stumpy, short-legged lizard. Its
earth-tone colors usually hide it. However, the skink startles
potential predators by suddenly opening its mouth and sticking
out its thick, blue tongue. It also huffs and puffs, hissing like a snake. Another Australian lizard that uses this startle display is
the blue-tongued skink, named for its turquoise tongue.
An Australian legless lizard called the excitable delma does
not have startling colors, but it still spooks predators with its
behavior. If bothered, this animal twists and turns its body violently
as it slithers away. This odd behavior may startle and confuse