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Basking in sunlight

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a sperm whale rests after its journey

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from the black depths of the ocean

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Sperm whales are the deepest diving
of all mammals

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and can spend up to ninety minutes
on the sea floor hunting giant squid

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and other bottom dwellers

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Like mammals on land

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all whales and their dolphin cousins
are warm-blooded

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and need to breathe air

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So, how have whales adapted
terrestrial organs

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to a life at sea so successfully?

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00:00:46,579 --> 00:00:48,843
And what prompted their ancestors
to move

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from the land to the oceans?

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WHALES

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The blue whale is the largest animal

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ever to have inhabited the planet

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Growing up to one hundred feet

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and weighing as much as one hundred
and ninety tons

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or three hundred eighty
thousand pounds

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lt is also extremely rare

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Only its need to breathe

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allows us a fleeting glimpse of
its legendary bulk

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The blue whale belongs to
the order Cetacea

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which includes the great whales

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and their much smaller relations

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porpoises and dolphins

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The smallest of dolphins is a fraction

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of the size of a blue whale's fluke

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At a little over four feet

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Hector's dolphins are also rare

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Their range is limited to a few
coastal areas of New Zealand

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where they hunt for fish
near the surface

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As mammals

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whales use lungs to breathe air rather
than gills to breathe water

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Whale's lungs are relatively small

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but they are remarkably efficient

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When a whale surfaces

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it can replace up to ninety percent
of the air

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in its lungs in just a few seconds

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But this efficiency alone
cannot account

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for its ability to stay underwater

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in some species,
for as long as two hours

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A diving whale descends

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with almost half its total oxygen
stored in the muscles

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where it is slowly
released overtime

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The whale uses this oxygen
with great economy

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Only essential organs,
such as the brain

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are supplied while others
go into oxygen debt

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until the animal returns
to the surface

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But the deep diving sperm whale needs
more than these adaptations

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lts bulbous head contains the so
called spermaceti organ

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Filled with a complex mixture of fats
and waxes

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one of the organ's functions is
almost certainly to act

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as a biological ballast tank

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When water is drawn into the huge
nasal passages

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the mixture cools and hardens helping
the whale to descend rapidly

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The process is reversed by ejecting
the water and pumping warm blood

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through the organ to liquefy the wax

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All whales have bones that
are light and filled

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with oil which acts as an aid
to buoyancy

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lt's also a vital energy reserve
during periods of fasting

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Whales are powerful swimmers
with tail flukes

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that are horizontal rather
than vertical, as in fish

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The flukes are boneless and consists
of strong, fibrous tissue

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Powered by a pair of massive muscle
blocks forward of the flukes

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whales cruise at six miles an hour

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with the fastest reported speed in
excess of forty miles an hour

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Unlike cold-blooded fish

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whales need to stay warm
in frigid waters

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Blubber, a layer of fat up to
twenty inches thick

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acts as thermal insulation

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But whales can also actively
conserve heat

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using warm blood pumped
from the heart

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Areas with little or no blubber

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such as the head and flukes

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operate a heat exchange system

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Cooled blood in the extremities
is partly heated as it passes

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by the warmer blood

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A vital adaptation because heat
from a body immersed in water

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is lost around twenty-five times
faster than in air

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The very cold waters, thousands of
feet below the surface

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are the natural hunting grounds of
the sperm whale

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Sperm whales are the largest of
the toothed whales

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part of the group that includes
the orca or killer whale

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With up to ten or twelve pairs of
cone-shaped teeth

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orcas can threaten even
the largest prey

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And it's the only whale
that can kill other whales

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Dolphins also belong to the
toothed whale group

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and feed on fast moving fish
and squid

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Dolphins have even moved into
some large rivers

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where they have become
highly specialized

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Primitive river dolphins like the
Amazon Buto have limited eyesight

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and use echolocation to find their
prey in murky waters

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Echolocation or sonar

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has only been used by humans since
World War l l. .

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. . . but evolved in toothed whales and
dolphins over millions of years

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Dolphins emit short pulses of
ultrasonic sound

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that bounce off objects
producing echoes

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which the animal uses to create sound
pictures of its surroundings

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Among the constantly shifting
ice floes

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and channels of the Arctic seas

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the ability to navigate beyond the
limits of vision is vital to survival

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Another toothed whale, the beluga. .

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. . . has extraordinary sensory skills

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including a highly tuned sonar
navigation system

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Complex muscles above the jaw focus
a beam of sound

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that produces a very precise image
of its surroundings

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enabling the whale to plot a safe route

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through channels under the ice

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The belugas may descend to
a thousand feet to

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echolocate scarce breathing holes
in the ice

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Their acute hearing also helps them
evade predatory polar bears

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The largest whales and therefore
the largest animals

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on Earth don't have teeth at all

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and feed on the world's
smallest animals

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These zooplankton in turn feed on
minute sea plants called phytoplankton

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Floating crustaceans known as krill
are among the larger zooplankton

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During the summer months

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their swarms form concentrations
dense enough

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to discolor surface waters
for many square miles

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These super swarms have
been estimated

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to weigh over two million tons

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A blue whale feeding on krill

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may take in one hundred thirty
pounds in one mouthful

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and up to four tons a day
in the richest Antarctic seas

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ln a unique adaptation

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some whales evolved baleen plates
as a simple replacement to teeth

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enabling them to harvest these swarms

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Rows of these plates are suspended

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from ridges in the upper jaw

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Baleen whales feed by simply
opening their mouths

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to take in both prey and water

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By closing their mouths and
raising up the tongue

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the water is expelled through the
baleen plates filtering out the food

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Baleen itself is made of keratin
like hair and fingernails

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> From hundreds of plates hang
countless hairlike fibers

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that can filter the vast
quantities of food

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Gray whales, the most primitive
of the toothless whales

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evolved thick, bristly baleen to

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rake the seabed dislodging crustaceans
embedded in the sand

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Many whales spend most of their
lives feeding

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but the oceans do not contain
endless supplies

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Off the coast of Baja, California

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blue and fin whales hunt for food

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ln the summer months

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the waters near the coast are
especially plentiful

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and so they and other whales
congregate in large numbers

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to cruise among the dense
shoals of fish

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The whales' activities incite
a feeding frenzy

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among pelicans and other sea birds

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Fin whales feed by lunging
moving rapidly sideways

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through shoals of prey with
mouths open

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Expandable throat pleats increase
the volume of water

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00:15:02,201 --> 00:15:04,169
and therefore the amount of
food taken in

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in a single lunge

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00:15:09,074 --> 00:15:11,304
Fin whales grow to over seventy feet

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on a relatively small range of foods
that include krill

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squid and some small fish

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Pelicans capitalize on the havoc
wrought by the feeding fin whales

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00:15:37,002 --> 00:15:39,937
Large whales also require enormous
amounts of food

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because they need to build up reserves

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for the less productive winter season

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Humpbacks cooperate to harvest the sea

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using a skillfully woven fishing
net to encircle their prey

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Swimming well below the surface

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00:16:05,264 --> 00:16:08,722
they weave a net by forcing bubbles
out through their blowholes

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by moving in a spiral beneath
a shoal of fish

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The bubbles drive the fish towards
the center of the net

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Surging towards the surface in unison

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00:16:25,718 --> 00:16:30,052
the humpbacks form an inescapable
phalanx of gaping mouths

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00:17:06,658 --> 00:17:09,855
Orcas or killer whales cooperate
in a different way

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Orcas can be aggressive
intelligent predators

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Here they deliberately beach themselves
to capture young sea lions

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Shoreline feeding has been passed
down through the generations

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Adults showing their young how to
achieve the best results

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This technique echoes the moment
in evolutionary time

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when the land bound ancestors of
all whales first became sea mammals

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00:18:15,394 --> 00:18:17,954
At that time
fifty-five million years ago

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the drifting continents were changing
the face of the Earth

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lndia moved north to collide
with Asia

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forming the massive heights of
the Himalayas from

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what was the floor of the ancient
Tethay Sea

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The remaining water which today
forms the Mediterranean

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became shallow and more saline

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fueling an explosion of sea life

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00:18:42,588 --> 00:18:45,819
On the edges of this remnant sea
in a primeval world

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of tropical swamps and estuaries

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lived a group of animals known
as Creodonts

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A sub-group of the Creodonts known

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00:18:55,300 --> 00:18:57,666
as the Mesonychids hunted
close to the water

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00:19:01,974 --> 00:19:06,138
Some ate plants, but others were
opportunistic scavengers

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00:19:06,245 --> 00:19:09,703
carnivores that fed on dead fish
washed up by the tide

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00:19:35,040 --> 00:19:38,669
Eventually these carnivores hunted
exclusively along the tide line

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00:19:39,411 --> 00:19:42,676
entering the surf to capture dead
or dying prey

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00:19:45,517 --> 00:19:46,814
Within a few million years

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00:19:47,352 --> 00:19:51,015
they had developed into semi-aquatic
creatures feeding wholly in the sea

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. . .the first primitive whales

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00:19:59,298 --> 00:20:00,356
ln the last few decades

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00:20:00,866 --> 00:20:03,767
scientists have gradually uncovered
the mystery. .

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00:20:03,869 --> 00:20:05,928
. . .of how a land mammal returned
to the sea

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00:20:08,407 --> 00:20:10,967
Near Santa Barbara on
the Californian coast

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00:20:11,276 --> 00:20:15,110
new finds like this twelve million
year old skull of a whale

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00:20:15,514 --> 00:20:18,950
are adding to an emerging picture
of how whales evolved

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00:20:19,818 --> 00:20:22,616
At this stage, scientists
Louise Kearin

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00:20:22,888 --> 00:20:25,118
and Lawrence Barnes are
not sure exactly

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00:20:25,390 --> 00:20:26,789
what is inside the rock

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00:20:29,661 --> 00:20:31,458
But painstaking excavation
will eventually

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00:20:31,663 --> 00:20:33,858
allow them to place this animal

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00:20:34,233 --> 00:20:36,292
within a complex
evolutionary jigsaw

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00:20:38,704 --> 00:20:40,763
One that is already
relatively complete

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00:20:57,556 --> 00:21:00,423
The whale story begins with
the amphibious animal

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00:21:00,525 --> 00:21:02,356
that evolved from Mesonychids

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00:21:07,499 --> 00:21:11,162
Pachocetus, the earliest known whale
still had four limbs

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00:21:11,570 --> 00:21:15,301
as it explored its aquatic environment
fifty million years ago

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00:21:17,709 --> 00:21:19,768
> From then on, they evolved rapidly

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00:21:20,379 --> 00:21:24,076
Ambliocetus had large hind feet
clearly adapted for swimming

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00:21:25,250 --> 00:21:27,878
Then later
Rotocetus evolved a feature

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00:21:28,120 --> 00:21:30,281
that enabled them to venture further
from the land

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00:21:31,323 --> 00:21:36,158
The tail vertebrae detached from
each other allowing the tail

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00:21:36,261 --> 00:21:37,455
to move up and down for propulsion

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00:21:40,399 --> 00:21:43,391
Ziggarisa lived around forty
million years ago

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00:21:43,869 --> 00:21:45,359
lt had a flexible forelimb

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00:21:46,238 --> 00:21:48,706
but the hind limb had now
almost disappeared

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00:21:53,011 --> 00:21:55,707
Ziggarisa showed another
important adaptation

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00:21:56,415 --> 00:21:58,940
The blowhole moved toward
the top of the head

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00:22:03,455 --> 00:22:05,252
ln just over ten million years

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00:22:05,924 --> 00:22:08,518
the early whales had left the
land forever

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00:22:13,932 --> 00:22:17,561
These primitive whales had teeth
designed to grasp and shear

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00:22:18,203 --> 00:22:20,398
but eventually they became
modified to

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00:22:20,605 --> 00:22:23,233
form long rows of sharp uniform teeth

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00:22:25,577 --> 00:22:26,874
Today's toothed whales, dolphins

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00:22:27,346 --> 00:22:31,112
orcas, and sperm whale
are their descendants

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00:22:36,388 --> 00:22:38,151
Around twenty-five million years ago

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00:22:38,590 --> 00:22:41,582
the baleen whales evolved
from a toothed ancestor

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00:22:42,527 --> 00:22:43,050
Even today

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00:22:43,161 --> 00:22:46,688
the fetuses of some baleen whales
have remnants of teeth

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00:22:57,175 --> 00:23:00,372
For a land mammal to have evolved
into the creatures we see today

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00:23:00,846 --> 00:23:02,404
such as this minke whale

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00:23:03,081 --> 00:23:05,743
evolution had to be chemical
as well as physical

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00:23:14,693 --> 00:23:17,662
Kidneys became specialized to deal
with excess salt

241
00:23:18,363 --> 00:23:23,824
Fluids covered the eyes to protect
them from the saline environment

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00:23:24,636 --> 00:23:26,661
No other mammal has
a covering so sleek

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00:23:36,915 --> 00:23:38,815
These small adjustments taken together

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00:23:39,017 --> 00:23:42,248
transformed medium-sized land mammals

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00:23:42,621 --> 00:23:44,452
into huge sea creatures

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00:23:52,063 --> 00:23:53,690
At just under one hundred feet long

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00:23:53,899 --> 00:23:58,666
a Boeing 7 37 is shorter than the
largest recorded blue whale

248
00:24:01,440 --> 00:24:04,534
A blue whale's heart is the size
of a Volkswagen

249
00:24:09,014 --> 00:24:12,609
And the whale itself is six times
heavier than the plane

250
00:24:17,956 --> 00:24:20,288
Their immense size
meant that the great whales

251
00:24:20,559 --> 00:24:22,925
were able to fuel a hemisphere

252
00:24:38,076 --> 00:24:40,840
Whale oil lit the continents
for many centuries

253
00:24:41,446 --> 00:24:45,246
and later lubricated the machines
of the lndustrial Age

254
00:24:54,259 --> 00:24:57,558
European and American whalers
made huge profits

255
00:24:57,863 --> 00:25:01,458
unaware they were hunting their
quarry to the edge of extinction

256
00:25:05,303 --> 00:25:07,328
Whales were not only killed for
their blubber

257
00:25:07,639 --> 00:25:10,335
The strong and flexible baleen
from their mouths

258
00:25:10,575 --> 00:25:12,600
was used in a range of
domestic products

259
00:25:12,878 --> 00:25:14,470
from corsets to umbrellas

260
00:25:18,216 --> 00:25:21,310
Decade after decade
tens of thousands of whales

261
00:25:21,486 --> 00:25:25,547
were slaughtered to satisfy the needs
of a burgeoning human population

262
00:25:38,503 --> 00:25:40,494
Herman Melville's story of Moby Dick

263
00:25:41,072 --> 00:25:43,233
the mythic great white sperm whale

264
00:25:43,808 --> 00:25:46,106
told of high adventure, obsession

265
00:25:46,511 --> 00:25:47,842
and an existence fraught with danger

266
00:25:53,585 --> 00:25:54,950
By the mid-1 9th Century

267
00:25:55,353 --> 00:25:57,651
whaling methods had changed little

268
00:25:57,889 --> 00:25:59,982
from earlier days of
subsistence hunting

269
00:26:00,792 --> 00:26:03,784
lt was still an intimate struggle
between men and whales

270
00:26:07,866 --> 00:26:09,629
A disaster was always looming

271
00:26:18,543 --> 00:26:19,805
By the turn of the 20th Century

272
00:26:19,978 --> 00:26:23,470
even the biggest whales were pursued
in the polar regions

273
00:26:23,582 --> 00:26:25,277
and processed in vast factories. .

274
00:26:25,917 --> 00:26:28,886
. . .yielding handsome profits to
the new whaling magnates

275
00:26:33,024 --> 00:26:36,050
Most highly prized was
the fine oily wax

276
00:26:36,294 --> 00:26:37,761
from the head of the sperm whale

277
00:26:38,163 --> 00:26:41,326
to be used to oil precision machinery

278
00:26:42,767 --> 00:26:44,291
But as catching methods changed

279
00:26:44,903 --> 00:26:46,268
so did the use of the whales

280
00:26:47,372 --> 00:26:49,772
Whale oil no longer lubricated
the world

281
00:26:50,275 --> 00:26:52,470
and carcasses were rendered
down for soap

282
00:26:52,777 --> 00:26:56,008
margarine, fertilizers, cosmetics

283
00:26:56,514 --> 00:26:59,176
and to provide food for pets
and farm animals

284
00:27:02,721 --> 00:27:04,382
''Thank you, Ladies and Gentlemen

285
00:27:04,489 --> 00:27:05,786
and welcome to Shamu Stadium.''

286
00:27:06,057 --> 00:27:08,890
Human attitudes have
changed significantly

287
00:27:08,994 --> 00:27:09,926
since mass whaling ended

288
00:27:10,495 --> 00:27:14,124
And whales now hold a special place
in our collective conscience

289
00:27:16,334 --> 00:27:16,993
''Come on, folks

290
00:27:17,102 --> 00:27:18,569
Now who wants to see some magic?''

291
00:27:43,595 --> 00:27:44,186
We've come to recognize

292
00:27:44,295 --> 00:27:48,789
that whales are highly intelligent
capable of sophisticated interaction

293
00:27:48,900 --> 00:27:56,102
with other species like ourselves
and able to imitate and learn

294
00:27:56,708 --> 00:27:57,936
Whales are even adaptable

295
00:27:58,243 --> 00:28:01,076
and successful in some pretty
unusual situations

296
00:28:16,194 --> 00:28:19,527
Whales and dolphins are essentially
social animals

297
00:28:22,767 --> 00:28:24,291
For some, like these dolphins

298
00:28:24,936 --> 00:28:26,460
belonging to a large group. .

299
00:28:26,671 --> 00:28:28,696
. . . has clear benefits for survival

300
00:28:30,308 --> 00:28:32,367
The chances of finding food
are increased

301
00:28:32,811 --> 00:28:36,076
since the group can range far wider
than one individual

302
00:28:46,157 --> 00:28:49,593
Collective defense against predators
is more likely to succeed

303
00:28:50,128 --> 00:28:53,723
and grouping helps bring individuals
together for breeding

304
00:29:03,708 --> 00:29:05,869
Dolphins can congregate
in the hundreds

305
00:29:06,444 --> 00:29:07,604
Their schools are fluid

306
00:29:08,079 --> 00:29:10,445
with individuals leaving to
join other groups

307
00:29:10,949 --> 00:29:13,782
but with a corps of members
that stays together

308
00:29:24,696 --> 00:29:26,857
The much larger whales rarely school

309
00:29:27,265 --> 00:29:29,130
and the closest bond is probably

310
00:29:29,334 --> 00:29:31,165
between a solitary mother and calf

311
00:29:32,537 --> 00:29:35,529
Baleen whales come together at
feeding grounds and to mate

312
00:29:36,007 --> 00:29:37,497
but then disperse rapidly

313
00:29:44,149 --> 00:29:45,047
However, sperm whales

314
00:29:45,383 --> 00:29:47,283
the largest of the toothed whales

315
00:29:47,519 --> 00:29:50,352
do group together in pods
in warmer waters

316
00:29:52,957 --> 00:29:54,788
Females form the corps of the pod

317
00:29:55,126 --> 00:29:56,525
which also consists of calves

318
00:29:56,895 --> 00:29:58,487
and juveniles of both sexes

319
00:30:09,507 --> 00:30:12,806
Sperm whale bulls spend most
of the year alone

320
00:30:12,911 --> 00:30:14,105
hunting in colder waters

321
00:30:15,013 --> 00:30:16,310
But during the breeding season

322
00:30:16,447 --> 00:30:18,813
they join the pod forming a harem

323
00:30:20,885 --> 00:30:24,252
ln this rarely filmed display of
strange and sensual behavior

324
00:30:24,956 --> 00:30:26,787
all the sperm whales in the pod

325
00:30:27,192 --> 00:30:29,285
form a knot of writhing bodies

326
00:30:36,835 --> 00:30:38,166
lts purpose is unclear

327
00:30:38,636 --> 00:30:42,732
but it may be a means of reinforcing
social bonds within the pod

328
00:31:05,196 --> 00:31:08,188
lt may also have a more
directly sexual function

329
00:31:08,633 --> 00:31:12,091
since this encounter seemed to
stimulate the immature males

330
00:31:49,908 --> 00:31:52,376
Pilot whales also live in tightly
knit groups

331
00:31:52,944 --> 00:31:55,674
but they are often led by
a single older female

332
00:31:56,881 --> 00:32:00,248
Strong social bonds like
these may hold a clue to

333
00:32:00,451 --> 00:32:02,942
one of the most perplexing mysteries
about whales

334
00:32:03,521 --> 00:32:06,490
their apparently deliberate
strandings on shore

335
00:32:09,327 --> 00:32:10,624
Evidence from stranding sites suggest

336
00:32:11,029 --> 00:32:15,227
that some animals had parasitic
infestations of the ear

337
00:32:15,934 --> 00:32:17,026
and brain to such a degree

338
00:32:17,268 --> 00:32:19,202
that it may have caused disorientation

339
00:32:20,338 --> 00:32:24,240
An infected dominant female could
easily lead her entire group

340
00:32:24,542 --> 00:32:26,305
into dangerously shallow waters

341
00:32:35,787 --> 00:32:37,379
But not all scientists agree

342
00:32:37,689 --> 00:32:39,919
that these infestations are
the only answer

343
00:32:40,892 --> 00:32:43,156
Others point to magnetite
particles found

344
00:32:43,394 --> 00:32:44,759
in the brain of several species

345
00:32:44,996 --> 00:32:47,362
that may be acting as
an internal compass

346
00:32:49,867 --> 00:32:52,358
These particles may detect
the Earth's magnetic field

347
00:32:52,770 --> 00:32:54,795
which originates deep within
the planet

348
00:32:55,106 --> 00:32:57,734
and draws an unseen grid across
the globe

349
00:32:59,110 --> 00:33:02,443
lf whales are using this geo-magnetic
information to navigate

350
00:33:02,981 --> 00:33:06,314
it's possible that this system breaks

351
00:33:06,417 --> 00:33:09,079
down leading them
into shallow water traps

352
00:33:19,330 --> 00:33:21,093
Some whales look like floating reefs

353
00:33:21,766 --> 00:33:25,998
They're a place in the vastness of
the sea for parasites to call home

354
00:33:29,040 --> 00:33:31,372
Whales are host to many kinds
of parasites

355
00:33:32,110 --> 00:33:35,443
Barnacles that attach themselves
to the skin do little harm

356
00:33:36,080 --> 00:33:38,344
but other creatures feed
on the whale's flesh

357
00:33:46,157 --> 00:33:50,253
Whale lice have claws that can cling
onto a rapidly moving animal

358
00:33:52,196 --> 00:33:54,721
and jaws designed to
pierce its flesh

359
00:34:00,038 --> 00:34:02,029
The lice may cause only
minor irritation

360
00:34:02,540 --> 00:34:05,998
but the whale's attempts to dislodge
them can be spectacular

361
00:34:26,330 --> 00:34:30,232
Spring arrives in the Arctic and
as the ice recedes

362
00:34:30,334 --> 00:34:31,733
it's a time for renewal

363
00:34:40,411 --> 00:34:42,072
Beluga whales move en masse

364
00:34:42,380 --> 00:34:44,974
from the ocean to the newly
reopened river inlets

365
00:34:54,992 --> 00:34:58,428
All whales shed skin and parasites
during their lives

366
00:34:59,030 --> 00:35:00,861
but belugas are the only whales

367
00:35:01,165 --> 00:35:03,690
that migrate to certain areas
in the Arctic

368
00:35:04,001 --> 00:35:06,265
specifically to molt their skin

369
00:35:10,508 --> 00:35:12,908
They wait for the tide to enter
the fresh water shallows

370
00:35:13,244 --> 00:35:17,271
where a gravel and sand river bed
will help them remove old skin

371
00:35:32,130 --> 00:35:32,994
During the year

372
00:35:33,264 --> 00:35:35,630
a coat of yellow-green
algae builds up

373
00:35:36,534 --> 00:35:38,126
on the upper body and this, too,
will be shed

374
00:35:58,222 --> 00:36:00,986
Small lead groups of beluga enter
the river mouth

375
00:36:01,459 --> 00:36:04,917
even though they are vulnerable to
polar bears in such shallow waters

376
00:36:17,842 --> 00:36:21,938
As the tide peaks, hundreds of
whales begin rubbing

377
00:36:22,046 --> 00:36:24,241
and scratching against the river
bed and each other

378
00:37:31,482 --> 00:37:32,414
After a few days

379
00:37:32,650 --> 00:37:35,210
they will return to their feeding
grounds in the open sea

380
00:37:35,786 --> 00:37:37,185
scarred in some places

381
00:37:37,755 --> 00:37:41,020
but parasite free and with
sleek white skin

382
00:37:53,304 --> 00:37:55,738
With the evolution of sociability
among whales

383
00:37:56,107 --> 00:37:59,076
came the development of highly
sophisticated communication

384
00:38:03,714 --> 00:38:06,342
Whales vocalize almost continuously

385
00:38:06,450 --> 00:38:07,815
and produce a range of sounds

386
00:38:07,985 --> 00:38:09,509
that is remarkably diverse

387
00:38:16,093 --> 00:38:20,530
Underwater, sound travels four times
faster and much further. .

388
00:38:20,731 --> 00:38:22,096
. . .than it does in air

389
00:38:23,134 --> 00:38:27,366
All whales need to emit sounds over
large distances for identification

390
00:38:27,638 --> 00:38:30,436
and to locate other whales in the
wilderness of the sea

391
00:38:37,782 --> 00:38:40,080
ln this way, whales constantly send

392
00:38:40,418 --> 00:38:44,115
and receive information about sex
and activity

393
00:38:49,627 --> 00:38:52,755
Sperm whales use a series of clicks
known as codas

394
00:39:13,884 --> 00:39:16,011
lt appears that one whale will call

395
00:39:16,420 --> 00:39:19,287
and another will answer with
exactly the same coda

396
00:39:20,157 --> 00:39:22,148
This will be repeated on
different occasions

397
00:39:22,259 --> 00:39:24,420
by different individuals
in the group

398
00:39:27,465 --> 00:39:31,094
ln other areas of the oceans,
populations of sperm whales

399
00:39:31,202 --> 00:39:34,797
have different codas indicating
the existence of dialects

400
00:39:35,039 --> 00:39:36,404
within the sperm whale language

401
00:39:48,953 --> 00:39:51,649
One of the more remarkable features
of whale communication

402
00:39:52,156 --> 00:39:56,490
is the plaintive alluring song of
a lone humpback whale

403
00:40:09,607 --> 00:40:11,165
ln an attempt to attract a mate

404
00:40:11,709 --> 00:40:14,269
a male may sing for more
than twenty-four hours

405
00:40:14,779 --> 00:40:16,906
with only a few short breaks
to breathe

406
00:40:18,082 --> 00:40:21,643
His song may last up to thirty-five
minutes before being repeated

407
00:40:23,154 --> 00:40:25,622
A whale's song is quite
clearly defined

408
00:40:26,323 --> 00:40:29,986
with a recognizable beginning
middle and end

409
00:40:31,929 --> 00:40:34,921
lndividual songs have their
own peculiarities

410
00:40:35,032 --> 00:40:37,523
their own syllables
phrases and themes

411
00:41:03,794 --> 00:41:05,557
Sound is one way of attracting a mate

412
00:41:06,564 --> 00:41:10,398
However for a female narwhal living
in icy Arctic waters

413
00:41:10,935 --> 00:41:14,427
sight takes precedence in the search
for a suitable partner

414
00:41:23,781 --> 00:41:28,047
Male narwhals which grow to about
fifteen feet have ivory tusks

415
00:41:28,152 --> 00:41:30,211
that are up to ten feet long

416
00:41:34,425 --> 00:41:36,791
Males joust with these
elongated swords

417
00:41:37,294 --> 00:41:39,956
which are both weapons
and symbols of dominance

418
00:41:48,672 --> 00:41:52,130
The successful competitor wins the
right to mate with females

419
00:41:52,743 --> 00:41:56,372
The strongest male passing on its
genes to future generations

420
00:42:13,464 --> 00:42:14,897
Among southern right whales

421
00:42:15,332 --> 00:42:17,357
male competition is intense

422
00:42:26,844 --> 00:42:30,405
The idea is not to be the first
to mate, but the last

423
00:42:31,849 --> 00:42:35,410
Because southern right males have
the largest testes on Earth

424
00:42:35,819 --> 00:42:37,650
each weighing close to half a ton

425
00:42:38,589 --> 00:42:42,616
the last male to mate not only
deposits huge quantities of sperm

426
00:42:43,360 --> 00:42:46,193
but washes out that of
the preceding males

427
00:42:47,064 --> 00:42:50,693
This gives his sperm the best chance
to reach the female's egg

428
00:43:09,587 --> 00:43:12,556
Many whales migrate huge
distances to mate

429
00:43:13,324 --> 00:43:15,724
But the master mariner is
the gray whale

430
00:43:16,427 --> 00:43:18,759
lts journey is the longest
of any mammal. .

431
00:43:19,263 --> 00:43:21,754
. . .an eleven thousand mile round trip

432
00:43:22,466 --> 00:43:25,333
From October
whales begin migrating south

433
00:43:25,603 --> 00:43:27,468
from the Bering Sea in
Gulf of Alaska

434
00:43:27,838 --> 00:43:29,703
hugging the North American coastline

435
00:43:29,940 --> 00:43:32,841
down to the warm water lagoons
of Baja California

436
00:43:38,015 --> 00:43:40,711
The annual migrations of gray
whales are synchronized

437
00:43:40,818 --> 00:43:42,376
with their mating patterns

438
00:43:43,287 --> 00:43:46,984
Conception and birth always occur
in these Baja waters

439
00:43:47,625 --> 00:43:50,219
because gestation periods
last twelve months

440
00:43:52,963 --> 00:43:54,396
Calving every two years

441
00:43:54,632 --> 00:43:57,260
places enormous biological
strain on those females

442
00:43:57,501 --> 00:43:58,866
that conceive regularly

443
00:43:59,536 --> 00:44:01,868
But the warm waters of tropical
breeding grounds

444
00:44:02,206 --> 00:44:03,798
may help sustain both females

445
00:44:04,041 --> 00:44:05,474
and their newborns

446
00:44:40,244 --> 00:44:42,872
Twelve feet long and eighteen
hundred pounds at birth

447
00:44:43,547 --> 00:44:46,277
a young humpback grows rapidly
over several months nourished

448
00:44:46,884 --> 00:44:51,821
by a rich milk that contains up to
fifty percent fat and protein

449
00:44:56,093 --> 00:44:57,025
Before it weans

450
00:44:57,394 --> 00:45:00,056
the young humpback may increase its
weight by five times

451
00:45:00,597 --> 00:45:03,657
feeding on a hundred fifty gallons
of milk each day

452
00:45:07,104 --> 00:45:08,628
Apart from the occasional snack

453
00:45:09,339 --> 00:45:12,103
a mother will not feed while
nursing its young

454
00:45:12,509 --> 00:45:15,672
even though a huge amount of energy
is used up to produce

455
00:45:15,779 --> 00:45:17,144
such a large offspring

456
00:45:26,090 --> 00:45:28,615
A mother must also protect
its young from threats

457
00:45:28,859 --> 00:45:30,224
that can come from any direction

458
00:45:31,295 --> 00:45:33,092
To a pack of hungry killer whales

459
00:45:33,664 --> 00:45:36,462
any newborn whale is a
tempting target

460
00:46:00,424 --> 00:46:02,756
Of course the greatest threat to
all whales comes

461
00:46:03,127 --> 00:46:05,220
from another species of
mammal altogether

462
00:46:17,141 --> 00:46:19,609
Humans began whaling during
the first migrations

463
00:46:19,843 --> 00:46:21,902
from Siberia to the Americas

464
00:46:26,817 --> 00:46:30,082
These early settlers survived
in a hostile environment

465
00:46:30,420 --> 00:46:33,480
by making full use of dead or
stranded

466
00:46:33,791 --> 00:46:36,316
whales as a rich source of food
oil and shelter

467
00:46:37,828 --> 00:46:39,455
Recognizing the whale's value

468
00:46:39,863 --> 00:46:43,321
they soon developed hunting techniques
to keep themselves supplied

469
00:46:43,534 --> 00:46:44,933
for the long winter months

470
00:46:57,381 --> 00:47:02,080
Today, subsistence whaling is still
part of life in the frozen North

471
00:47:09,960 --> 00:47:13,259
This narwhal will provide good eating
for the weeks ahead

472
00:47:13,931 --> 00:47:15,956
The skin and blubber will
be cut and dried

473
00:47:16,066 --> 00:47:18,591
providing food that is rich
in Vitamin C

474
00:47:41,491 --> 00:47:44,619
ln earlier days the slower species
that came close to the shore

475
00:47:44,895 --> 00:47:48,558
such as the bowhead and right whales
were hunted in open boats

476
00:47:49,199 --> 00:47:50,962
using hand-crafted spears

477
00:47:52,336 --> 00:47:55,828
Most of the animal would have been
used including dried bones

478
00:47:55,939 --> 00:47:58,066
used to construct frames for shelters

479
00:48:05,115 --> 00:48:07,879
The annual catch of whale
populations was small

480
00:48:08,418 --> 00:48:11,353
and life in the Arctic remained
relatively stable

481
00:48:11,455 --> 00:48:14,515
for many centuries until the coming
of a new threat

482
00:48:14,625 --> 00:48:16,718
the commercial whalers

483
00:48:22,399 --> 00:48:26,062
But today the mass slaughter of the
great whales is all but over

484
00:48:32,843 --> 00:48:34,333
Conservation groups fought long

485
00:48:34,678 --> 00:48:36,475
and hard to close the
whaling stations

486
00:48:37,414 --> 00:48:39,507
but by the time mass
whaling had ended

487
00:48:39,883 --> 00:48:43,284
over three-quarters of the world's
population of great whales

488
00:48:43,387 --> 00:48:44,513
had been obliterated

489
00:48:49,059 --> 00:48:51,721
Communities that once depended
on the whaling trade

490
00:48:51,828 --> 00:48:54,023
are now sustained by a new industry

491
00:48:54,898 --> 00:48:56,695
Whale Watching Eco-Tourism

492
00:49:18,355 --> 00:49:22,223
Even though many of the whales are
protected as endangered species

493
00:49:22,326 --> 00:49:26,490
it may be a century or more before
the most heavily hunted can recover

494
00:49:35,906 --> 00:49:40,639
One positive step came in 1 994 with
the creation of a Southern sanctuary

495
00:49:40,744 --> 00:49:42,974
in the seas surrounding Antarctica

496
00:49:43,547 --> 00:49:47,381
a haven for eighty percent of the
world's remaining great whales

497
00:49:53,590 --> 00:49:55,353
During the fifty million
year odyssey

498
00:49:55,592 --> 00:49:58,220
myriad sea mammals evolved
from a terrestrial creature

499
00:49:58,328 --> 00:50:01,024
that hunted the shores of
ancient oceans

500
00:50:16,213 --> 00:50:17,805
They gradually lost those features

501
00:50:18,148 --> 00:50:19,638
that associated them with
the land

502
00:50:20,083 --> 00:50:21,983
now spawning their young
into the oceans

503
00:50:23,553 --> 00:50:25,851
where they would spend their
entire lives

504
00:50:30,594 --> 00:50:34,826
Adaptations to new food sources
created a mammal without teeth

505
00:50:35,198 --> 00:50:36,529
the baleen whale

506
00:50:38,602 --> 00:50:41,537
New ways evolved to navigate the
immensity of the sea

507
00:50:42,139 --> 00:50:45,006
to dive to the bottom of the ocean

508
00:50:45,308 --> 00:50:47,037
and overcome the dangers of the deep

509
00:50:52,649 --> 00:50:55,880
They became social animals that now
hunt together

510
00:50:56,286 --> 00:51:02,418
play together and call out across
the ocean vastness

511
00:51:29,786 --> 00:51:39,752
THE END

512
00:51:40,752 --> 00:51:50,752
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