Animals have evolved many defenses against predators, including fleeing, using toxic chemicals from glands or food, camouflage, mimicry, grouping together, and playing dead or emitting foul smells. Specific examples include poison dart frogs and fire salamanders releasing toxins from skin glands, octopuses and hagfish releasing slime, and monarch butterflies and coral snakes using bright colors to warn of toxicity through mimicry and aposematism.

1. Animal Defense against
Predators

2. Animal Defense Against Predators
Throughout millions of years of evolution, animals
have evolved numerous ways of defending themselves
against predators. Obviously, being able to flee
a predator is the choice of many prey animals we
can consider.
However, there are some often overlooked but
interesting methods of defense which involve deception
and chemistry. These include using toxic chemicals,
camouflage, and mimicry.

3. Animal Defense Against Predators
Presented here are several descriptions
and
examples of animal defense.

4. 1. Chemical Defense
 There are two main ways animals can use
chemicals to defend themselves.
 Animals can synthesize toxin using their
own metabolic processes, or they can
accumulate toxin from the food they eat.

5. 1. Chemical Defense
 Animals which synthesize
their own toxin are able
to convert chemical
compounds in their body
to a poison.
► There are many
amphibians that produce
skin toxins. The skin
toxins are produced by
special poison glands,
usually located on the
animal's back or
throughout the skin. The poison dart frog has
poison glands scattered
all over its body.
Photo courtesy of Dr. John Daly

6. •Malaysian ants internally
combust under threat,
causing their bodies to
explode (they wait until their
enemies are close enough to
die before
detonating).Camponotus
saundersi soldier ants have
large glands full of poison
inside their bodies. When
they sense a threat, they
contract their abs, causing
the glands on either side of
their bodies to explode and
spray poison.

7. The Pacific
Ocean Hagfish has a
disgusting way of defending
itself. When under attack,
it oozes a suffocating slime
from its many pores that
envelops its predator in a
fatal mass of fibrous goo.
The hagfish, unfortunately,
sometimes falls prey to its
own defense mechanism, but
normally it twists itself into
knots to escape the
gelatinous goop

8. The bombardier
beetle may look innocent
enough, but it is famous
for being able to spray
boiling hot and
chemically toxic bodily
fluids in the direction of
any would-be predator.
The bombardier beetle
doesn't exactly melt in
your mouth (but it will
melt you).

9. Chemical Defense
In another
example, the fire
salamander makes
a nerve poison,
which it can
squirt from glands
on its back.
Photo courtesy of Henk Wallays, Cal. Acad. of Sciences.

10. Chemical Defense
Many animals accumulate
toxin from their food
rather than synthesizing it
from scratch.
For example, the larvae of
Monarch butterflies accumulate
toxins from the plants they
inhabit. Birds that eat the
Monarchs vomit and learn to
avoid them in the future.
Their bright coloration allows
birds to remember and avoid
them.
Photo courtesy of T. W. Davies, Cal. Acad. of Sciences.

11. Chemical Defense
► Interestingly, many organisms
which are distasteful advertise
this fact to predators by having
bright body colors or markings,
as if to say, “Notice me! I’m
dangerous!”

12. Chemical Defense
You can see this in the
bright colors of the
Monarch and the
poison dart frog.
Photo courtesy of Dr. John Daly
Photo courtesy of T. W. Davies, Cal. Acad. of Sciences.

13. Physical Defenses
This is called “aposematic
coloration”, and is widely
used among the insects
and amphibians.
The Cream-spot Tiger is
aposematically colored.
Aposematism is the advertising by an
animal to potential predators that it is
not worth attacking or eating. This
unprofitability may consist of any
defences which make the prey difficult
to kill and eat, such as toxicity, venom,
foul taste or smell, sharp spines, or
aggressive nature.

14. 2. Camouflage/cryptic
coloration
Animals that
camouflage themselves
pretend to be
something they are
not. Either their
coloration, marking
patterns, or entire
body resembles
something else in their
environment

15. orchid mantis

16. Gecko

17. Flying lizard

18. 2. Camouflage
Here an aptly named
walking stick pretends to
be a twig, in an attempt to
avoid being seen by a bird
or other predator. This is
an example of cryptic
coloration.
Photo courtesy of Dr. Lloyd Glenn Ingles, Cal. Acad. of Sciences.
Camouflage is the use of any
combination of materials,
coloration, or illumination for
concealment, either by making
animals or objects hard to see,
or by disguising them as
something else.

19. Camouflage
In this picture, a four-
eyed butterfly fish uses
deceptive markings.
The large spot near the
tail resembles an eye.
When predators attack
the wrong end, the
butterfly fish can swim
away in the other
direction!

20. Camouflage
Some predators also depend on camouflage, but
this time it is in order to avoid being seen by their
prey.
Here, a frogfish resembles
a sponge. Small fish
swimming nearby will be
engulfed in the frogfish’s
enormous mouth!

21. 3. Mimicry
In mimicry, an organism (the mimic) closely
resembles another organism (the model) in
order to deceive a third, (the operator). The
model and the mimic are not always closely
related, but both usually live in the same area.
This is similar to camouflage, but in mimicry
the model is generally a similar organism rather
than a static part of the background
environment.

22. 3. Mimicry
There are several types of mimicry.
The two most common types are
Batesian mimicry and
Mullerian mimicry.

23. 3. Mimicry
Batesian mimicry occurs when an edible mimic
resembles an unpalatable or poisonous model. In
this type of mimicry, only the mimic benefits.
An example of
Batesian
mimicry is the
scarlet king
snake, a non-
poisonous
mimic of the
extremely
venemous coral
snake. Above: scarlet king snake
Right: coral snake
Photo courtesy of John H. Tashjian,
Cal. Acad. of Sciences.

24. Mimicry
Another example of
Batesian mimicry is
the locust borer.
This insect not only
looks like a bee or
wasp, it sounds like
one, too!

25. Mimicry
By contrast, Mullerian mimicry occurs
when two (or more) distasteful or
poisonous organisms resemble each other.
Both species benefit because a predator
who learns to avoid one species will most
likely avoid the other, too.

26. Mimicry
The two invertebrates on the left are different species
of sea slugs, while the one on the right is a marine
flatworm. All three secrete noxious substances and
are unpalatable. Notice their similar aposematic
coloring.

28. Fly Orchid

29. •Physical means of Defense
The South American Three Banded
Armadillo is the only one that can roll
into a perfect ball; this is
accomplished thanks to its loosely
jointed armor which allows for a
greater range of movement, and to
its armored head and tail which
interlock when the animal rolls into a
ball, thus making it completely
invulnerable to most enemies.
This animal has also been known to
shut closed at the last moment,
making a snapping sound to startle
its enemies as a clever additional
defensive trick .

30. Found in Africa and southern Europe
(mainly in Italy), the Crested Porcupine is
among the largest rodents in the world,
and also among the best protected
mammals. Its quills, which have black and
white banding so that predators can spot
them from the distance, are actually
modified hairs, covered with layers of hard
keratin. These quills are longer in the front
part of the body, forming an erectile crest
that gives the animal its name. However,
the most dangerous quills are the short
ones in the back of the body. When
threatened by a predator, the porcupine
usually shakes its tail quills, which are
hollow and sound like a rattle; if this
doesn’t scare the enemy away, the
porcupine charges backwards, trying to
stab the predator with its back quills.

31. •Physical means of
defense The hairy frog or "horror frog"
intentionally breaks its own bones
to turn out a wicked set of cat-like
claws. Like Wolverine, only slimy
and a lot more terrifying
because it's a freaking frog.
Scientists don't know if the claw is
able to retract once it pierces
through the skin. According to New
Scientist: "Trichobatrachus
robustus actively breaks its own
bones to produce claws that
puncture their way out of the frog's
toe pads, probably when it is
threatened." Also, it is apparently
hairy.

32. Behavioral Defenses
•Living in groups
– maintain a
tight cohesive
group that it
would be difficult
for any predator
to obtain a
victim.

33. The cute little Opossum has a
number of tricks up its
defensive sleeve. It can play
dead. It can foam at the mouth
in an attempt to convince its
predators that it is toxic, sick. It
can also emit a green anal fluid
that smells nearly as bad as a
skunk's offensive spray (though
mercifully it can easily be
washed off). Opossums playing
dead actually slip into a semi-
comatose state, thus removing
any excitement of the kill for a
predator.

34. Predators mechanism of hunting tactics
Ambush hunting – lying in wait for prey to come along. It has a
low frequency of success and it requires minimal energy.
Example Frog, alligator, crocodile, lizards
Stalking – form of hunting with a quick attack. The potential
predator’s search time may be great but pursuit time is
minimal.
Example herons, cats
Pursuit hunting – involves minimal search time because the
predator usually knows the location of the prey, but pursuit
time is usually great.
Example Hawks, Lions, wolves

35. Characteristics of Predation
1. If prey population increases, it will support more
predators.
2. The number of predators tend to go low than the prey
because the predator being large has a slower rate of
increase.
3. More prey will escape the predators if there is much
cover.
4. When the prey populations falls, it becomes
unprofitable for the predator to pursue the prey, it
must shift to some other source or suffer decline.
5. Predation maintains the balance of animal production.

36. 6. Predators selectively remove the young, old and
diseased individuals from the prey populations.
Predation functions as a natural method of quality
control by removing individuals which are slow, weak
and incapable.
7. The alert, healthy and well adapted animals are less
likely to fall as victim to the predator.
8. Method of biological control of pests animals
particularly insects and rodents.
9. Occurrence of various adaptations in response to
predation.

37. Thank you for listening