Killer whales

From: Kim Marshall-Tilas (kimm@oceanalliance.org)
Date: Tue May 28 2002 - 17:30:52 EDT


Question: Which is smarter, killer whales or humans?
Reply: My personal opinion is that the whales are smarter because I respect
how they live in highly formed social groups. But judging intelligence is
not easy. If you go by brain size, the killer whale does have a large brain
as do humans. There are many ways of measuring intelligence but most of
them are based on human intelligence so the results can be baised. There is
no right answer to your question -sorry! I have listed below some basic
orca information but don't forget to search through WhaleNet to find our
more about their behaviors. Thank you!

    Orca whales, or killer whales, are medium sized whales which live in all
oceans of the world. The only limitations to where they can be found is
food (they canšt live in places where no food is available) and surface ice
(they need to breathe, so ice canšt be covering too large of an area).
    Orcas are recognizable by the distinct white markings on their mostly
glossy black bodies. A killer whale has an oval-shaped eye patch behind
each eye. Its chin and chest are also white. This white patch extends into
a white stripe down its belly to its tail. From an orcašs belly, the white
stripe extends up into white patches on the lower part of the whalešs sides,
between the tail and the dorsal fin (the fin on top of the whalešs back).
There is one more identifying mark, and that is the whitish patch on the
orcašs saddle, or the place right behind the dorsal fin. The color here
varies between white and different shades of gray. Every orca whalešs
markings are different, and some have less or more white than others. There
are even a few orcas that are all black or all white!
    Male orcas grow up to between 27 feet and 33 feet long. Females are a
little smaller. They are typically about 23 feet long, but the largest
female orca found was over 28 feet long. One amazing thing about orcas are
the sizes of their dorsal fins. Females have dorsal fins up to 3 and 1/3
feet tall, and males can have even larger fins, up to six feet!
    Even though orcas are not the largest whale, they are fierce predators.
They usually eat fish, especially herring and salmon, but if they are
hungry, they will eat almost anything including seabirds, sea turtles, seals
and sea lions, and even other whales. When they do attack other, larger
whales, it is often because they cannot find other food.
    Orcas often hunt in packs, much like wolves. A pack will surround their
prey so that it canšt swim away, and then they take bites of it until they
kill it or until they are full. If they attack another whale, they choose
the weakest whale they find and attack its lips, tongue, and belly.
However, the large whales have a defense. They have huge, powerful tails,
and can hit their attackers very hard. One person reported seeing a killer
whale thrown 30 feet away from its prey!
    Orcas usually travel in pods, or groups, of 5 to 30 whales. However,
sometimes they are solitary, while other times pods as large as 100 whales
or even more have been seen! The leader of the pod is usually a mature
female. Most whales, when they grow up, stay in their motheršs pod until
she dies. When she dies, one of the older females may take over the
leadership of the pod, or the pod may split, with two or more mature females
taking on the leaderships of the new pods.
    In these pods, we can often see different types of behavior among the
killer whales. Some of them are also seen in other whales. Some of the
behaviors that killer whales perform are:

1) Breaching: the whale jumps out of the water, headfirst, and lands on its
belly or twists in the air to land on its side or back
2) Flipper slapping: when the orca slaps the surface of the water with its
flippers
3) Lobtailing: the orca sticks its tail out of the water and slaps it onto
the surface
4) Spyhopping: in order to take a look around above water, the whale sticks
its head and part of its chest out of the water. Sometimes several orcas
will do this at the same time.
5) Speed-swimming: the whale travels fast and most of its body leaves the
water when it surfaces to breathe. Orcas can travel as fast as 34 miles per
hour!
6) Logging: a whole pod faces the same direction
7) Dorsal fin slapping: The orca rolls onto its side and slaps the water
with its dorsal fin

    Female orcas, or cows, are pregnant once every 3 to 8 years. A mother
carries her baby, or calf, for 17 months before it is born. Most calves are
born during the autumn. At birth, a newborn orca is 7 to 8 1/2 feet long
and weighs about 390 pounds! Its white patches are not yet white--they are
tan or yellow in color until it gets older. It nurses its motheršs milk
(remember that whales are mammals and feed just like human babies do) for
several months, and begins eating solid food at about five months old. By
nine months old, a baby orca eats mostly solid food, though it may still
nurse occasionally for a few months. At this point, the orca is eating an
equivalent of 4 to 5 percent of its own body weight every single day.
Imagine if you weighed 80 pounds--you would eat 3 to 4.5 pounds of food each
day if you ate like an orca.
    Orcas are in danger from only one other animal--humans. Orcas are not
usually hunted, and are not yet endangered, but they are sometimes killed by
native peoples whose only food is meat from animals they can catch. They
are also taken by commercial whalers occasionally if they are in the path of
a hunt for another type of whale. More threatening, however, is pollution
in the oceans. Chemicals from many different manufacturing and processing
plants, and trash from companies and from everyonešs homes often end up in
the oceans, where they can hurt all sealife. Chemical pollutants build up
in the bodies of animals and are passed on to their offspring. Trash can be
swallowed by sealife, or animals can get tangled up in it. So far, effects
of chemical pollutants have not been seen in orcas, but they have been seen
in other marine mammals and birds, including beluga whales and albatrosses.
These pollutants cause birth defects in young animals, causing them to die
before they are born or at a young age.
    To save the orcas and their environment from pollutants, you can help
keep pollutants from getting into our oceans. You can use recycled,
non-bleached paper for your schoolwork and for drawing, and you can help
your parents recycle paper, plastic, glass, aluminum, and tin. In your area
there may even be more things you can recycle. Use less water when you
shower, brush your teeth, and wash clothes and dishes. This helps the
environment by reducing the amount of energy used to move the water to your
house. You can also write to your local politicians and ask them to vote for
policies that will help the environment.
    Last but not least, keep learning more about whales and the environment
through organizations like Whale Conservation Institute and through your
local school and public libraries! The more you learn, the more you can
help other people learn about whales and the things that are threatening
their survival. It is only with the help of special, interested and
dedicated kids like you that we can all change the world.

Bibliography (you can look for these books in your local libraries):

 1) Carwardine, Mark. 1995. Whales, Dolphins, and Porpoises. Dorling
Kindersley, New York, 256 pp.

2) Cousteau, Jacques-Yves and Yves Paccalet. Jacques Cousteau Whales.
Harry N. Abrams, Inc., New York, 280 pp.

3) Leatherwood, Stephen et al. 1988. Whales, Dolphins, and Porpoises of
the eastern north pacific and adjacent arctic waters. A guide to their
identification. Dover Publications, Inc., New York, 245 pp.

4) IUCN (The World Conservation Union). 1991. Dolphins, Porpises, and
Whales of the World. The IUCN Red Data Book. Cambridge, U.K., 429 pp.

---------------------------------------------------------------------
Kim Marshall-Tilas
Executive Director
Ocean Alliance
(Encompassing the Whale Conservation Inst. & the Voyage of the Odyssey)
191 Weston Road, Lincoln, MA 01773
781-259-0423 x 14 fax: 781-259-0288
www.oceanalliance.org www.pbs.org/odyssey



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