Killer Whales

From: Kim Marshall (kimm@oceanalliance.org)
Date: Wed Sep 24 2003 - 17:06:05 EDT

  • Next message: Kim Marshall: "Whale Facts"

    > Question: I was just wandering how many killer whales are there still in the
    > wild?? Also where are most of them located??
    >
    > Reply:
    > Dear Chelsea,
    > Orca whales, or killer whales, are medium sized whales which live in all
    > oceans of the world. The exact population number is hard to predict. 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, Porpoises, and Whales
    > of the World. The IUCN Red Data Book. Cambridge, U.K., 429 pp.
    >
    >



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