Adaptation 6
Coping with Dangers- Animals.
Avoidance Behaviour
 This is a type of behaviour which helps an animal avoid danger
 E.g. snail withdrawing into a shell; blinking when something flies
towards your face.
 This is unlearned behaviour
 Has a survival value.
Habituation
 If the stimulus that prompted avoidance behaviour is repeated
many times, then the organism would stop responding- this is called
habituation.
 This means the animal doesn’t waste energy responding to a
stimulus that is not harmful.
 This is a type of learned behaviour.
 Habituation is a short-lived response, and after a few days the
organism would show the avoidance behaviour again.
Learning
 This is a long term modification of response to given stimuli.
 If learning allows animals to avoid dangerous situations or
poisonous animals or plants, then it increases the animals’ chance of
survival.
 In order to learn an organism must be capable of remembering.
Imprinting
 This is a type of learning that can only occur during a brief period
of early life.
 It is a behavioural adaptation to aid survival.
 E.g. newly hatched ducklings and gosling quickly learn to follow the
first large object they meet, as long as it moves and makes a noise!!
The young birds assume that this is their mother and that by
staying close they will be protected. See Figure 26.6 on page 212
of Torrance.
Individual Mechanisms for Defence
1. Active
 Snails withdraw into their shells when attacked
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The skunk produces a foul smelling liquid which it squirts at
enemies.
Long legged animals like antelope and ostriches can flee at high
speed.
The octopus can create its own “cover” by ejecting an inky
“smokescreen” which aids escape.
Some birds carry out distraction displays to protect their young.
Avocets, for example, can pretend to be injured to draw a predator
away from their nest and then quickly fly off to safety.
An extension of this is “playing dead” (e.g. grass snake) to deter
predators that feed exclusively on freshly-killed prey.
2. Passive
 Some butterflies have developed a false head on their rear wings,
with eye spots and false antennae. When birds attack it, they are
actually attacking its rear end. This is less damaging to the
butterfly, which can escape by appearing to fly off backwards.
 Many animals have protective outer coverings, e.g. shells on
limpets, armour plating of the armadillo, caterpillars which have
bristles with barbed filaments that can give a painful sting when
touched, spines on a hedgehog.
 Camouflage (remember the peppered moth?) allows animals to avoid
being seen by predators. The flounder fish can change the
intensity of its colouring to resemble the background it is on. (See
Figure 26.11 on page 215 of Torrance)
 Some South American tree frogs are highly coloured to advertise
the fact that they are highly poisonous.
 Some animals have colourings that mimic harmful or unpalatable
species, e.g. the harmless hoverfly mimicking a wasp.
Social Mechanisms for Defence
 By staying together as a large group, many animals rely on “safety
in numbers”. Some animals in the group can keep a lookout while
other feed.
 Prairie dogs (small rodent sized animals) live in burrows, but need
to come out to feed. One member of the group is always on sentry
duty whilst the others are feeding. If the sentry spots a predator
it lets out a series of whistling barks to alert the rest of the
group- which can then make their escape.
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Musk oxen, when threatened form a protective group with the
young and females at the centre, and the males on the outside with
their huge horns facing outwards. This is called mobbing.
Quail roost in circles with their heads tucked away but facing to
the outside. If the group is disturbed, the quails “explode” in the
predator’s face- causing alarm, and allowing time for the quail to
fly away.
Baboons have a hierarchy with dominant males. When the troop is
moving the dominant males are on the inside near the females and
infants. The lower ranking males are on the outside of the troop, on
the lookout for danger and are responsible for raising the alarm as
required.
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