Hi boys and girls, today we're going to take up a topic that
has seemed to be one of the most interesting in this wonderful
world of nature of ours.
We're going to be talking about the adaptations of animals.
Now adaptations are specializations
of animals which enable them to do a better job of living
in their particular habitat.
Now do you all remember that word habitat?
We talked about it last week you know.
Habitat is the environment or the place in
which animals live and we talked about a number of different
kinds of habitats last week.
We talked about marshlands and we talked about woodlands
and we talked again about prairie lands or grasslands.
Now what do we mean by an adaptation?
Well an adaptation is a specialization of
a particular part of an animal which enables it
to fit more perfectly into its chosen environment.
Now in the case of muskrats, muskrats are animals which
live in the marshlands.
The marshlands have water and they have ground which
is very wet.
They have a variety of vegetation
of cat tails and sedules.
And the animal that lives in this type of
habitat is the muskrat.
If you will take a look here now at this animal which
I have in my hand, this is a study skin of a muskrat.
A study skin is actually a skin of the animal which is stuff
to preserve the skin.
It is not mounted in a particular life
like fashion but it is merely put up in this way to preserve
it so that we can study it.
Now what are some of the adaptations of this muskrat
which enable it to do such a good job of living in
its marshland environment?
Well first of all we know that the muskrats live in
water. Actually spend a great deal of their time right
in the water and beneath the surface of the water.
So it is necessary for them to keep dry and warm while
they are in the water.
And the coat of the muskrat is the part of the rat that
is specialized and enables the animal to live in the water.
The coat is made up of two kinds of hairs, a rather long
stiff outer hair which protects and keeps dry the inner hair.
And the inner hair is very fine and soft and is
what we usually call fur.
And this fur keeps the animal dry and warm even
though it is beneath the surface of the water.
Now what are some of the other specializations or
adaptations of this animal?
Certainly the animal does a good bit of swimming.
And if we look at the feet of the muskrat we find
first of all that the hind feet are very large in
comparison with the front feet.
Notice that they are three or four times the size of the hind
feet are three or four times the size of the front feet.
And the hind feet have an edging of stiff hairs around them
which increase the surface of the foot and enable the rat to
do an excellent job of swimming.
When the muskrat swims the four feet are not used but
rather the hind feet are used to paddle exclusively.
Now the tail is also specialized.
You can see here that the tail
is somewhat flattened.
And this flattened tail acts as a rudder as the animal swims.
In other words the animal the muskrat steers with its tail.
Now going from this marshland environment we can probably next
go to the woodland and study some animal and animal which is
adapted to living in a woodland.
And the animal I have selected for this is the flying squirrel.
This picture of flying squirrels shows the animal
in their natural habitat and you can notice off to
the left of the picture a flying squirrel gliding
from one tree to another.
Notice the large folds of skin between the front leg
and the hind leg which act as a regular parachute.
Notice also how the animal's tail is acting as a parachute
as the animal glides from one tree to another.
It doesn't actually fly but rather sails
from one place to another.
Now here is a skin of a flying squirrel.
These tiny little squirrels are the smallest of
all of our squirrels.
This is the full grown flying squirrel.
Now let's take a look at some of the adaptations
of this flying squirrel.
First of all between the hind feet and the fore feet we find
a little full of skin which in the live animal can be
expanded and spreads out to increase the body surface of the
animal and allow it to glide.
Also another specialization is to be found in the animal's
tail. Notice that the flying squirrel has quite a different
tail from the regular red squirrel and gray squirrel
and fox squirrels.
Notice how flat and thin the tail
of the flying squirrel is.
Also notice that the hair is very stiff in this tail and
this tail acts as a parachute and also as a rudder as the
animal sails from tree to tree.
The feet of the flying squirrel too are specialized
and the long toes have very sharp claws which enable
the animal to climb the trees with a great deal of ease.
So this little flying squirrel is particularly adapted
to a life in the trees.
Now the next animals that I would like to talk about are
some animals that are adapted to living their life beneath
the surface of the ground, particularly in the grasslands.
The first animal I would like to talk about is this one here
and this is a pocket gopher.
It is an animal a rodent that is found in the
northwestern part of Wisconsin in the sandy soil areas.
If we look at the skin of a pocket gopher we find that
it is rather a medium sized little animal about 8 inches
long, a very heavy-bodied animal with short legs
and rather a short tail.
The eyes of the pocket gopher and the ears are rather
small. I don't know whether you can see them here.
Here is the eye and the ear.
But the eyes and ears of this animal are quite small because
the animal spends most of its life in burrows beneath
the surface of the ground.
It feeds on the roots and stems of plants that it finds there.
Now one of the most amazing adaptations of the pocket
gopher is to be found in the animals 4 feet.
Notice how very short the 4 feet of this animal are.
Notice how large the feet are and what
very long sharp claws it has.
These long sharp claws and short powerful forelegs enable
the animal to dig through the soil with tremendous rapidity.
It can travel at a very rapidly digging its
way through the soil.
In contrast, look at how small the hind feet of
the pocket gopher are.
In the muskrat you recall the 4 feet are a were small and the
hind feet were large.
In this case just the opposite is true.
And of course the reason for this is that this animal uses
its 4 feet to dig its burrows.
Another interesting adaptation of the pocket gopher in the
adaptation which gives the animal its name are the pockets.
On either side of the animal's head are two little fur-line
pockets and I'm going to run this piece of paper down into
these pockets so that you can see where they are located.
Right there and right here.
These pockets are quite deep and they are used by the
animal to carry food in and the animal also uses them to
carry soil from its burrows up to the surface of the ground.
Now the next animal that I'd like to talk about is another
one which is also adapted to a life hundred ground.
And the adaptations of this animal are even more extreme
than that of the pocket gopher.
The picture you see is that of a mole in its burrow and
as you see the picture here the animal is feeding on
an earthworm in its burrow.
If we look closely at this skin of a mole it's rather
difficult to tell just what which end is which.
And because the animal does not have an external eye
the eyes are completely closed as are the ears.
But it does have a rather short naked nose.
The other end of the animal we find a rather short naked
tail. So it's difficult to tell just where whether this
mole is coming or going.
If we turn the animal over we can see that the four feet of
the mole are certainly adapted to its way of life beneath
the surface of the ground.
Because these two large four feet are regular little spades
or shovels which enable the animal to dig through the soil
almost as fast as it can walk on the surface of the soil.
Notice two that the hind feet of the animal are quite small.
Now still another adaptation of the mole is to be found
in the animal's fur.
It's a beautiful silvery fur and it
is interesting because it is possible to smooth this fur
both forward and backward.
And this adaptation allows the animal to move both ahead
and backward in its burrow without picking up a lot of
soil in its fur and in this way this enables it to keep clean.
Now I have still one other animal that I'd like to show
you. A couple of weeks ago I was out in the woods and I happened
to run across a rather small, a possum out wandering around.
And I decided to pick him up and bring him along and show
him to you boys and girls to show you what some adaptations
on a living animal look like.
And here is our friend the possum.
The possum spends part of the life living in trees.
And so it has a number of adaptations which enable it to
get about in trees.
First of all take a look at the possum's
tail. Notice how this possum winds its tail around my finger.
This is what we call a prehand-style tail or a
tail that the animal can use to balance itself or
to hold onto a branch or limb as it climbs in a tree.
The four feet of the possum, the paws are almost hand-like
with long sharp nails which enable the animal to climb.
The most interesting thing about this animal is to be
found in a tine feet.
Behind feet of the possum look
almost like your hand and my hand.
Notice that it has these four fingers and a thumb.
This is what we call an opposable thumb.
In other words it is a thumb that works against
the fingers in this fashion.
And so this allows the possum to grasp branches and limb
as it climbs about a tree.
And these are the adaptations which enable the possum
to live in trees much more easily than an animal
that does not have them.
Now in conclusion today what can we say about these adaptations?
Well these adaptations are specializations which allow
an animal to live in a particular type of habitat
and do a very good job of it.
But they are specializations, the animal becomes so
specialized that it has a great deal of difficulty
living anywhere else.
For example our little friend the flying squirrel, if it
did not have trees to live in and was forced to live
on the ground, certainly would not live very long.
Because it cannot travel very fast and would soon fall
prey to any of the predators.
The same is true of the pocket golfer and the mole.
If they were forced to live on the
surface of the ground rather than beneath the ground they
too would not live very long.
So these adaptations specialize the animal to such an extent
that it must have a particular type of habitat if it is to
be successful and is to live.
So long for now boys and girls.
Each Monday afternoon at 2 o'clock the Wisconsin School
of the Air presents Robert Ellerson University of
Wisconsin Extension Specialist in Wildlife Management in
the wonderful world of nature.
This series of programs is designed for in-school
viewing by children in grades 5 through 9.
Next Monday at 2 our television classroom will again view the
wonderful world of nature and we invite you to join us then.
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