How do Scientists Know What They

Know?

Jean Pennycook

www.penguinscience.com

How do Scientists Know What They Know?

Our society relies on Scientists to unlock the mysteries of the world. From plate tectonics, to cells, to how the Universe works, generations of men and women have spent their lives searching for the patterns of life and the rhythm of the Earth’s systems.

Animal Biologists work to understand how other species live. Since we can not talk to the other animals, to learn about their lives requires carefully planned experiments. This program will explore how penguin scientists have learned how Adélie Penguins survive in the harsh environment of Antarctica.

Ross Island, Antarctica.

The location of three breeding colonies of Adélie Penguins currently being monitored by our research team, Penguin Science.

Cape Royds

Cape Bird

Cape Crozier

Here are some of the questions penguin biologists have wondered about.

Do penguins always return to their natal (birth) colony?

Do penguins mate for life?

How long do penguins live in the wild?

What do penguins feed their chicks?

How much food does it take to raise a chick?

Where do penguins go to feed?

How deep can they dive?

Where do Adélie Penguins go in the winter?

Do penguins always return to their natal (birth) colony?Do penguins mate for life? How long do penguins live in the wild?

How do we know?

This is a penguin flipper band. The number tells us what year and which colony the bird was born in.

When the chicks are big enough and ready to be banded we catch them in a corral.

Then we climb in the corral, catch them one by one and place the small metal band around their left flipper.

Putting the band on a chick

A banded adult bird

Banding does not interfere with the bird’s ability to swim or find food.

It may take 2-4 years before we see the bird after banding it, as Adélie Penguins do not reach breeding maturity until then.

Searching for banded birds in a colony. The red arrow points to the scientist. It takes a long time to find all the bands and read the numbers. Would you like this job?

That’s how we know

Do penguins always return to their natal (birth) nesting colony?

Most of the time they do, but sometimes we find them at different colonies. What causes them to move is not clearly understood.

This graph shows the number of Adélie Penguins born at Cape Royds that have been seen over the years at three other colonies in the area.

Do penguins mate for life?

Frequently they do stay with the same mate, but as they arrive at the breeding colony independently of each other, sometimes they will find a new mate. If the old mate shows up after this, sometimes there is a fight.

How long do penguins live in the wild?

We have seen them as old as 20 years, but that is rare.

That’s how we know?

How do we know?What do the penguins feed their chicks?

Orange means krill Silver means fish

We sit and wait for a returning parent to feed their chicks and then record the color of the food. This is called data by direct observation. We record our observations in a field journal every day.

That’s how we know.

What do the penguins feed the chicks?

Sometimes krill and sometimes fish,

But what kind of fish?

How do the Scientist know what kind of fish the penguins are eating?

Otoliths are fish ear bones. They are not digested and pass through the penguins into the guano (poop). We gather the guano and examine it under the stereoscope.

Otolith tray set out at the beginning of the season.

Otolith tray during the season with penguins nesting and pooping in it.

After the guano has been washed from the tray, we sort through it under the scope looking for the ear bones (otoliths).

1 mm

Otolith

This bone will tell the scientist what kind of fish the penguins are eating and how big the fish is.

How much food does it take to raise a chick?

How do we know?

Penguins are tagged that belong to the breeding colony inside the fence. Only way to go in or out is over the “weighbridge” (the arrow points to the weighbridge). The computer inside the tent records the information.

The small electronic ID tag is inserted into the penguin using the needle. It does not hurt the penguin to do this, and the tag does not interfere with the penguin’s life.

The hoop records the tag number of the penguin as it comes and goes from the colony. The platform measures the penguin’s weight as it passes through. The computer records the date, time and weight of each penguin.

Weighbridge

Solar panels keep the weighbridge computer running.

That’s how we know.

How much food does it take to raise a chick?

Subtracting the incoming weight from the outgoing weight of a feeding parent over the course of the chick rearing season gives us the amount they are feeding the chicks. It takes about 60 pounds of food to raise an Adélie Penguin chick.

How do we know?

Where do penguins go to feed?

How deep do penguins dive?

These (splash) tags are attached to the feathers of the bird and are only on for about 2 days. They record the diving depth and location of the bird as it feeds. We need to retrieve the tag to get all the information.

Here is the data from the splash tags, showing where the birds are searching for food to feed their chicks.

Where do Adélie Penguins go to feed?

See the map showing where penguins from two different colonies were tracked.

How deep do penguins dive?

Adélie Penguins have been recorded diving as deep as 170 m and staying submerged for just over 5 min.

That’s how we know.

How do we know?

Where do Adélie Penguins go in the winter?

This GLS (Geolocation sensor) tag attached to the bird’s leg stays on all year and records where the bird goes.

A map produced from the data of one GLS tag showing the location of the penguin all winter. Each color represents a different month.

70oS

Where do Adélie Penguins go in the winter?

The Adélie Penguins at Cape Royds and Cape Crozier migrate over 12 000 km from their breeding colony out to the wintering grounds near the pack ice edge and back.

That’s how we know.

There are still many unanswered questions about Adélie Penguins, as well as all the other plants and animals of the world. If being a Biologist sounds like fun, you are right, it is. Biologists work in every habitat of the world and there is much work to be done.

Other PowerPoint presentations for you classroom:

Introduction to the Polar regions, Why is Antarctica so cold?

Introduction to Adélie Penguins, Adélie Penguins march into the classroom

Penguin Adaptations, This is a harsh continent

Adélie Penguin Behavior, Good manners are always in style

Penguin Predation and Competition, Life is tough for an Adélie Penguin

Adélie Penguins Cope with Global Climate Change

Did You Know, How researchers know what they know

Penguin Quandaries, Can you answer these mysteries

Fun pictures about Adélie Penguin

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Adélie Penguins go to

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