Killer Whales
Kingdom:
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Animalia
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Phylum:
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Chordata
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Class:
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Mammalia
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Order:
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Cetacea
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[Suborder]:
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Odontoceti
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Family:
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Delphinidae
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Genus:
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Orcinus
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Species:
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orca
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What is taxonomy?
Though killer whales, also called orcas,
are considered whales by most people, they are actually members of the
Delphinidae (dolphin) family. Killer whales are excellent hunters that a wide range of prey, including fish, seals, and big whales such as blue whales. Despite their hunting of other animals, free-ranging killer whales have never been reported killing a human being.
Interesting Facts: - Killer whales are social animals that live in stable family-related groups. Killer whales display a high level of care for their offspring. In addition to the mothers, various pod members (mainly adolescent females) perform most of the care for the calves. As with most mammals, killer whales are very protective of their young.
- Different killer whale pods "sound" different. Each pod has their own dialect of sounds. They can easily recognize their own pod from several miles away based on the differences in calls.
- Killer whales are often compared to wolves because both species are top predators, maintain complex social relationships, and hunt cooperatively.
- To some, killer whales look exactly alike however they can be distinguished from one another by the shape and size of their dorsal fins, the distinctive grayish-white saddle patches behind their dorsal fins, as well as distinctive scars, nicks and marks on their dorsal fins.
What should I know about killer whales?
- Where do killer whales live?
- How many killer whales are there?
- How can I identify a killer whale?
- How well do killer whales see or hear?
- What do killer whales eat?
- How do killer whales have their young?
- How long do killer whales live? How do they die?
- Where can I find more information about killer whales?
Killer whales can be found in all oceans but
they seem to prefer coastal waters and cooler regions. Killer whales
occur in family groups called pods. Three types of pods have been
described:
- Resident pods: remain stable over time
- Transient pods: dynamic in structure (are constantly changing)
- Offshore pods: Are seen only in outer coast waters and not much else is known of them.
Killer whale pods are based on the lineage of the
mother (mothers, daughters, and sons form groups); the whales live
and travel with their mothers even after they are full-grown, forming
strongly matriarchal whale societies.
There are no official killer whale worldwide
population estimates. There are minimum counts in local areas. For
example, approximately 1000 whales have been individually identified
in Alaskan waters through photographs. Killer whales are at the top of
the food chain and are not considered endangered.
You can read more about killer whale stocks in the NMFS Alaska and Atlantic stock assessment reports.
Killer whales are extremely distinctive with
jet-black bodies and white patches usually over the eyes, under the jaw,
on the belly, and extending onto their sides. Female killer whales
can grow up to 26 feet (7.9 meters) with a 3 foot dorsal fin while
males are larger than the females growing up to 28 feet (8.5 meters)
with a 6 foot (1.3 meters) dorsal fin. Killer whales have 48 to 52
teeth that are large and conical shaped as well as slightly curved
back and inward.
Killer whales have well-developed, acute
senses. They can hear a vast range of sounds and possess skin that is
sensitive to touch. Killer whales have excellent vision in and out
of water. It is not known whether or not they may have some sort of
sense of taste.
The killer whale diet consists of fish, squid,
seals, sea lions, penguins, dolphins, porpoises and large whales like
the blue whale. Some killer whales have been known to slide on to
beaches in order to capture a good meal. Resident pods (pods that
primarily reside in one area) prefer fish whereas transient pods (pods
that travel over a relatively wide area) appear to target other
marine mammals as prey.
Killer whales are very successful hunters due to their cooperative hunting, where all animals within the pod participate. This coordination is apparently developed and learned within pods.
Killer whales are very successful hunters due to their cooperative hunting, where all animals within the pod participate. This coordination is apparently developed and learned within pods.
Killer whale males reach breeding age when they
are around 22 feet (6.7 meters) long while females can breed when
they are about 16 feet (4.9 meters) long. Killer whales breed all year
around and calves are born about 8 feet (2.4 meters) long after a 17
month gestation period. Female killer whales usually give birth every 3
to 10 years.
Killer whales have no natural predators (they
are the top predators of the oceans) and can live to about 50-80 years
old. Killer whales have been hunted by humans but not with enthusiasm
as it takes 21 killer whales to produce the same amount of oil as 1 sperm whale.
Where can I find more information about killer whales?
Books and the world wide web are excellent places to learn more about marine mammals.
Books
- Leatherwood, Stephen. Reeves, Randall R. Foster, Larry. The Sierra Handbook of Whales and Dolphins. Sierra Club, San Francisco, CA. 1983.
- Leatherwood, Stephen. Reeves, Randall R. Perrin, William F. Evans, William E. Whales, Dolphins, and Porpoises of the Eastern North Pacific and Adjacent Arctic waters; A Guide to their Identification. Dover Publications, Inc., New York, NY. 1988.
- Wynne, Kate. Folkens, Pieter. Guide to Marine Mammals of Alaska. Alaska Sea Grant Program. University of Alaska Fairbanks, Fairbanks, AK. 1992.
World Wide Web
- NMFS Stock Assessment Report
- The Biologicaldiversity.org.
http://www.biologicaldiversity.org/swcbd/species/orca/. - The Vancouver Aquarium.
http://www.killerwhale.org/index2.html. - The Whale Museum at Friday Harbor, Washington.
http://www.whale-museum.org/.
There are many more sources to learn about cetaceans. Check with NMML's online library or your local librarian for her or his recommendations.
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