How do Scientists Know What They Know?

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How do Scientists Know What They Know?
Jean Pennycook www.penguinscience.com
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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
Earths 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.
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Ross Island, Antarctica. The location of three
breeding colonies of Adélie Penguins currently
being monitored by our research team, Penguin
Science.
Cape Bird
Cape Crozier
Cape Royds
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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?
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How do we know?
Do penguins always return to their natal (birth)
colony? Do penguins mate for life? How long do
penguins live in the wild?
This is a penguin flipper band. The number tells
us what year and which colony the bird was born
in.
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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.
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Banding does not interfere with the birds
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.
Putting the band on a chick
A banded adult bird
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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?
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Thats 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.
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Thats how we know?
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.
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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.
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Thats 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?
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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.
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After the guano has been washed from the tray, we
sort through it under the scope looking for the
ear bones (otoliths).
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Otolith This bone will tell the scientist what
kind of fish the penguins are eating and how big
the fish is.
1 mm
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How do we know?
How much food does it take to raise a chick?
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.
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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 penguins life.
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Weighbridge
Solar panels keep the weighbridge computer
running.
The hoop records the tag number of the penguin as
it comes and goes from the colony. The platform
measures the penguins weight as it passes
through. The computer records the date, time and
weight of each penguin.
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Thats 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.
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How do we know? Where do penguins go to
feed? How deep do penguins dive?
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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.
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Here is the data from the splash tags, showing
where the birds are searching for food to feed
their chicks.
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Thats how we know.
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.
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How do we know? Where do Adélie Penguins go in
the winter?
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This GLS (Geolocation sensor) tag attached to
the birds leg stays on all year and records
where the bird goes.
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A map produced from the data of one GLS tag
showing the location of the penguin all winter.
Each color represents a different month.
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Thats how we know.
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.
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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.
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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
Go to www.penguinscience.com The education
page.
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To learn more about Adélie Penguins go to
www.penguinscience.com