Music This is how nature works!

Theme Music Music It's hard to believe that nearly all the energy our bodies use comes from the sun.

A hamburger looks like a hamburger, not a glowing ball in the sky.

We don't see the steer that became the hamburger, the plants where it got its energy, or the sun that shone the energy on the plants in the first place.

Solar energy can come to us in a hamburger because different kinds of living things on Earth are linked together.

The energy comes up through a chain of those links called the food chain.

One important link is between animals that consume plants and those that consume other animals.

Living things can be linked in lots of different ways.

One organism may help another reproduce or may provide shelter for another.

One may spread another’s seeds, or one may consume another.

These connections are called interrelationships.

The food chain that brings energy from the sun to an animal, like you or me, is a set of interrelationships.

Plants are at the basis of the food chain.

They make their own food and provide all the food for the whole chain.

They're called producers.

The rest of the living things still make their own food, but live on food made by plants for other organisms.

They're called consumers.

One of the most important interrelationships is between producers and consumers.

Some kinds of animals are named for by they eat.

For example, animals that survive by eating only plants are called herbivores.

Herb means plants, and vore means eater.

Herbivores’ mouthparts are adapted for eating plants, with parts that can cut leaves or grind fibers.

Animals that eat only other animals in order to survive are called carnivores.

Carn means meat.

Carnivores are adapted to catching and eating animals.

Even with these adaptations, carnivores work hard for their food.

Most prey animals are good at avoiding them.

Carnivores such as sea lions, walruses, and seals hunt in the ocean.

Their feet are finned, good for hunting in the water, so they're called fin-footed or pinnipeds.

Their shape helps them shoot through the water and make it easier to catch fish, crabs, and other animals.

Carnivores attack what’s easiest to catch, such as young, old, or sick animals.

That weeds out healthy animals and checks the population of the prey animals, helping to keep the community healthy.

Animals that eat both plants or animals are called omnivores.

All means everything.

Humans are omnivores.

Black bears, striped skunks, raccoons, common crows, American robins, and box turtles are all omnivores.

Because they tolerate variety in their diet, omnivores tend to do well in many environments.

Raccoon and opossum easily live near humans.

Even after seeing all these links in the food chain, it's still hard to believe that all these animals get their food from the sun.

Animals don't always fit into categories.

There are some bats that'll only eat insects, so we call them insectivores.

Let's go to the nature center and see what kind of bats Dave has there.

Music Hey, Dave.

Do you need some help feeding that big brown bat?

Oh, I sure could.

You mind getting that container over there and counting out some mealworms for me?

Sure.

So that's your insectivores.

All they eat are insects, right?

Well, some are, including this species right here.

In fact, about 700 species or 70% of the bats in the world are insect eaters.

So we could call them insectivores.

We could also call them predators because they eat other animals.

But not all predators, of course, are insectivores.

Those that eat meat like birds or mammals are actually called carnivores.

We can say they're carnivorous.

Now, bats like this eat tremendous number of insects.

They don't always eat insects like we're feeding them here.

We're feeding them mealworms or beetle larva today.

Usually they're eating flying insects that they capture out of the air.

In the wild, bats hibernate.

Right?

These bats would hibernate in the wild, but not all bats hibernate.

In fact, any animal that can't find enough food has to do one of three things.

Either find another food that it can find and eat, or some bats will migrate like many of our songbirds do because they eat insects, they can't find insects, go south where they can find insects.

Or, you eat enough when the going's good, eat a lot of insects late in the summer, put on enough fat and use that energy to get you through the winter time.

And those are the hibernators.

Do humans and bats share similar communities?

Well, in this case, you could say they do because big brown bats, as well as the little brown myotis, both species of bats are often found underneath people's shutters or up in their attics if they have access.

That's only because we've had an impact on them.

And long ago, bats like this used to use large, dead, hollow trees for their shelter and roosts.

But most of those places are gone.

So they've been smart enough and adapted well enough to, to move in with us and find shelter there.

We've had a lot of impact on a lot of wildlife over the years when you think about it.

In fact, a good example of a carnivore that's been impacted by humans is the great wolf.

Music Gray wolves once roamed most of the Northern hemisphere, but their range is now limited to Canada, the northern United States, and parts of Europe and Asia.

Wolf populations have dwindled due to hunting and human development.

In some parts of North America, the gray wolf is an endangered species.

Most wolves are about five feet long, from the tip of their nose to their tail, and weigh between 55 and 115 pounds.

They have thick fur that can be gray, white, tan, or black.

Wolves are very social animals that live in packs.

Most packs have 4 to 7 wolves, but some have as many as 15 wolves in them.

The size of the pack is usually determined by how much food is available, and how many wolves get along with each other.

The pack is made up of a family, including the alpha male and alpha female and their offspring.

All members of the pack have a rank.

The Alpha wolves are the dominant wolves, and rank determines who gets to eat first and who can mate.

Because wolves are social animals, communication is very important.

Wolves use vocal displays, scent marking, and visual displays like facial and body postures to communicate.

Wolves who are submissive will lick the noses of dominant wolves and crouch down to show that they're not a threat.

Vocal displays like howling are used for gathering the pack together before a hunt and to mark territory.

Wolves also howl to locate lost members of the pack.

The alpha male and female mate for life, and are usually the only pair in the pack to breed.

When raising their young, wolves use a den.

In the spring, the female gives birth to 5 or 6 or as many as 9 pups.

When the pups are about three weeks old, they come out of the den and play near its entrance.

Wolves travel long distances.

Their territories can cover up to 260 square miles.

Wolves are very fast and can run at speeds up to 30 miles an hour for short distances.

All members of the pack help care for the young.

When the pack goes to hunt, one wolf stays behind and guards the pups.

When they return from a hunt, pups run out, jumping and biting at the wolves’ noses and throats.

This causes the wolves to regurgitate undigested food.

The pups and the wolf that stayed behind eat the regurgitated food.

Gray wolves find their prey by scent.

Because they hunt in packs, they can catch large prey like deer, caribou, and moose.

They eat all parts of the carcass, including fur and bones.

Lone wolves hunt smaller prey like rabbits and fish, mice and birds.

Wolves can be a threat to livestock like chickens and sheep, and as a result are sometimes shot by farmers and ranchers.

Thousands of years ago, humans domesticated wolves because they admired their social and hunting abilities.

All of today's many breeds of dogs, from Saint Bernards to chihuahuas, are their descendants.

You know, Patrice, another great hunter, is the bat.

Sarah and Cody are going to spend the day finding out more about bats with Peter Benson from the Nature Conservancy.

Music There’s one.

You see one?

There’s one.

Where?

Hey!

Oh, yeah.

How many bats are in this cave?

In the wintertime, we usually have somewhere between 1200 and 1600 bats in the cave.

There are some bats in other parts of the country where they have a lot more bats than this.

Hundreds of thousands of bats.

See his little tongue?

What is the coldest temperature that bats can survive?

Well, they're like us.

The biggest problem these bats have in the wintertime is people coming in and disturbing them.

And they'll fly out into the cold air and literally either freeze to death or use up so much of their fat reserves that they'll starve to death over the course of the winter.

They can't survive very cold.

This cave that we're in right now in the mine, it's a constant temperature all year round.

It's between 40 and 45 degrees, winter and summer.

So in the summer it's nice and cool, but in the winter it's just warm enough for them to be able to survive.

Music If the bats don't stay and hibernate, where do they migrate?

A lot of them migrate to your chimneys and warm spots in houses.

Most people don't realize that some bats will stay in houses.

Any place that there's a warm spot for the winter.

A lot of them will just continue to fly south.

To the south, Southeast has a large concentration of bats.

And they'll go there for the winter.

Or they can stay active where there's insects or they can hibernate there as well.

You notice these bats are getting ready for hibernation.

They're all very, very chubby.

Think most of them look like little footballs.

In the spring, we’ll come in and they'll be almost flat.

They'll be very, very skinny because they would have been living on their fat reserves for the whole winter and not eating at all.

Now let’s go, because the bats know that we’re here.

What do bats eat?

Bats eat insects.

Mostly flying insects.

A lot of the insects that bother us.

Bats love mosquitoes and things like black flies and other flies.

An adult bat can eat hundreds of mosquitoes in a night.

So they really are a great control for the population of mosquitoes and other flying insects.

What would it be like if there were no bats around?

Well, there'd be a lot more insects around.

There'd be a lot more mosquitoes.

The bats are part of the, they're part of the food chain.

They're part of the circle of life.

If you remove one thing from the food chain, it might not make a difference, but it might make a big difference.

So we like to keep as many of them around as possible because they are part of the natural system.

Music Bye bye, bat.

I said bye to bat.

What have we learned today?

In the natural world, all living things are connected.

Herbivores are animals that eat plants.

Animals that eat only other animals in order to survive are carnivores.

Herbivores and carnivores have both structural and behavioral adaptations that help them to survive.

Now you know how nature works!

Theme Music Major funding for Nature Works was provided by American Honda Foundation.

Additional funding was provided by Alice Freeman Muchnic Alice J. Reen Charitable Trust, Cogswell Benevolent Trust, the Finisterre Fund, Greater Piscataqua Community Foundation, Morgridge Family Trust, the Natural Areas Wildlife Fund, Rawson L. Wood.

(animal sounds)