Important Information About Predators
a small amount of the sun's energy to be passed along through each
animal. When an animal dies, it decomposes, or breaks down, and provides
the soil with nutrients that help plants to transform the sun's energy
into food once again.
a food web
Balance of Nature
it looks like
a pyramid with the apex predator at the top and the plants eaters
at the bottom. Plant eaters are the most abundant part of the web.
It is said that
the predators in a particular area control the populations of prey
species. In this way, the prey species won't overpopulate and destroy
the habitat. This seems logical enough, but it is too simple to
fully explain what goes on in nature. One thing to remember is that
populations of predators and prey do not remain constant. There
are many factors which cause the numbers to rise and fall.
have a degree of balance; the number of plants and animals tend
to remain within a certain limit, which is not too great or not
too small. Predators, however, are not the only factor of population
control. A variety of things cause the abundance of a species, including
predators, food availability, competition with other species, disease
and even the weather.
Hawks are among the many predators that catch their prey by chasing
it. Chasing takes both time and effort to make a successful
capture. To be successful, predators that chase their prey must
concentrate on species that will provide enough nutrition to offset
the energy burned while chasing. This is one reason why the hawk
tends to eat more rodents and birds than grasshoppers. Grasshoppers
just don't provide enough food value to justify the effort it takes
to catch them.
use a different technique, the stalk.. Standing motionless
in shallow water or wading slowly along the shore, the heron patiently
searches for prey. When a heron sees its prey it captures it with
a quick lunge of its long, sharp beak. This method does not require
much energy. The downfall is the amount of time it takes to search
for food. A stalking predator can afford to choose smaller prey
and still meet its energy requirements.
ambush: The alligator prefers to lie still and wait. This
method of hunting requires little effort, but chances of getting
food are low. The cold-blooded alligator has minimal energy requirements.
It can get by with infrequent meals. Most ambush hunters are fairly
small because a successful ambush depends on the predator avoiding
detection until it strikes.
animals hunt in teams. Wolves, lions, hyenas, coyotes and killer
whales will usually live and hunt in family teams. Not only can they
pursue larger and sometimes faster prey, but family groups can protect
their little ones from other large predators. There's even a tropical
insect that hunts as part of a team. South American army ants travel
in the tens of thousands and devour every living thing in their path;
insects, snakes, livestock, rats and mice. There aren't many creatures
that can withstand marching army ants!
refer to the ability to smell, see or hear, taste and touch.
often the most important sense for a predator. A predator's eyes
are usually located in front of its head. The forward location of
the eyes gives binocular-type vision. The area that each eye sees
overlaps so the brain receives two slightly different messages about
the same scene. This will help a predator determine how far away
prey is. It also tells the predator how fast its prey is moving.
Birds and insects
must have the ability to catch prey in the air. A bird of prey's
telescope-like vision can be eight times stronger than ours. Some
predators rely on more sets of eyes than just one! Spiders and scorpions
have clusters of six to eight eyes. Some of the eyes form the image.
Others estimate distance, and still others detect motion. It's amazing
though, even with eight eyes, a spider can only see about 1 foot
in front of its face.
hunt at night (nocturnal predators) have special mirror-like structures
in the back of their eyes. These structures help the animal to see
in the dark. Deep sea animals have the same structures.
have a very good sense of hearing. In mammals, external ear
flaps can be swiveled forward or backward in order to pinpoint the
direction of a sound. The ears of bats are often highly specialized,
with strange shapes that help catch the echoes of the calls they
make as they fly. Birds can hear very well, too. Owls are thought
to have the most outstanding hearing of any animal. Their ears are
offset, which means one is higher than the other.
This is another
way to pinpoint the source of the sound. Some animals don't need
ears to hear. Instead, they rely on vibrations they feel
in their bodies. Ground vibrations from moving prey animals are
transmitted through the bones of salamanders and snakes to the nerves
near their ears. Sharks can monitor vibrations in the water with
a lateral-line system. Fluid-filled canals lie just beneath the
shark's skin along the sides of its head and body. The canals are
filled with small pores open to the water. Underwater noises or
motion cause a vibration that strikes these open pores. A shark
tunes into the vibration and looks for its next meal.
can smell a meal from a mile away! Foxes are even able to
smell food which is buried under two feet of soil. Some use their
sense of smell to follow the footsteps or tracks of an animal.
A shark has
outstanding smelling ability, but it works a bit differently. Their
nostrils are not for breathing, but are used for sensing odor. Water
flows in and out of the nostrils. A shark is able to identify the
different smells found in the water. Amazingly, a shark can smell
its prey from 2 miles away!
Snakes use their
tongues to smell. You might see a snake flicking its tongue around.
The snake is not getting ready to bite. It is smelling the air by
picking up dust particles. These particles are carried to taste
detectors in the snake's mouth. The taste tells snakes what animals
These are used
to help kill the prey and are used for "knives and forks" while
eating the prey. Most animals have three kinds of teeth.
In the front, you'll find incisors. These are used to cut food.
On the sides, you'll see longer teeth which are used for tearing
chunks of flesh off of the prey. Canine teeth can also be used to
kill the prey by piercing the neck or throat. Molars are found towards
the back of the mouth. They are flat and strong and used to chew
or grind. Some animals, such as crocodiles and sharks, have long,
cone shaped teeth. These are used for grasping the prey and pulling
it underwater. When underwater, the prey will drown enabling the
predator to eat it.
as well as teeth are important adaptations to seize and subdue their
prey. Powerful muscles provide leverage and gripping power at the
front part of the jaws. Some snakes are able to unhinge their jaws.
This allows them to swallow a meal which is much larger than the
snake's own head!
In some cases,
beaks take the place of teeth. Each beak tells a story about
its owner. Long beaks are used for probing, hooked beaks for tearing,
thick ones for crunching seeds, thin ones for picking insects. Beaks
provide birds with a lightweight alternative to a mouthful of teeth
- like hollow bones, they are an adaptation for flying.
are also powerful weapons. Birds of prey have powerful claws, called
talons which help the raptor to grab its prey. Most big cats have
claws that they use to grip and tear. They are able to pull in these
claws when walking or running. This keeps them sharp. Moles and
hedgehogs use their claws to dig up insects. In the same manner,
grizzly bears dig up roots and burrowing rodents. Of course, on
the grizzly, the claws are on the "tip of the weapon." A grizzly's
powerful paw can bring an animal down with one swipe.
use their tongue as an effective weapon. A chameleon has one of
the fastest tongues. It shoots its sticky tongue out towards the
prey, which is coated with a glue-like substance which captures
and swallows the prey. Did you know anteaters have tongues as long
as a person's arm? This adaptation helps an anteater to reach areas
where he or she needs to reach.
weapon is poison. Snakes use their poison, which comes from
their fangs, to paralyze or kill their prey. A spider releases strong
digestive enzymes that turn the prey's insides to liquid. A straw-like
mouth enables the spider to suck up the liquid. Wasps and scorpions
paralyze their prey by using powerful stingers. A jellyfish uses
its deadly tentacles.
2. Counter Shading
3. Disruptive Coloration
three types of camouflage.
1. One way is when an animal's coloring is similar to its surroundings.
Now you know why desert animals are often brown and jungle animals
are often green.
2. Another type
of camouflage is called counter shading. A counter shaded
animal is darkest on the top of its body and lightest on the bottom.
From a distance these animals seem to turn into one color and look
3. A third type
of camouflage is called disruptive coloration. A zebra has
disruptive coloration. Its stripes help it to hide when it is grazing
near trees and bushes. Does a tiger have disruptive coloration,
as well? Why?
change color with the season. This helps them to blend in with their
surroundings when their surroundings change. Imitation is another
form of camouflage. Some animals look like other animals. For the
most part, this helps prey species. Bright coloration which seems
opposite of camouflage, is it actually is used to warn animals to
stay away. Brightly colored animals may be poisonous or have an