killer whales gentle giants or viscous killers essay

“Killer Whales: Gentle Giants, or Viscous Killers?”

Killer whales are an important subject of mythology for many

indigenous peoples, especially the Native Americans of the Pacific

Northwest. The whales have not been hunted extensively by humans,

although they have been hunted by some shore whaling operations, and

some individuals have been taken as aquarium show animals from the

waters around the Pacific Northwest and Iceland. Killer whales are

perceived by many near-shore fishermen to be in competition with human

fishing activity (Anheiser Busch 1).

The killer whale, or Orcinus orca can be found worldwide in all seas

from both tropics to Arctic and Antarctic oceans. They are one of the most

well known whales because of the captivity of Shamu at Sea World and the

other studies that are widely publicized (2). The male killer whale has an

average length of 6.7 to 7.0 meters and can weigh between 4,000 to 5,000

kilograms (Knight 5). The female killer whales are smaller having a length

of 5.5 to 6.5 meters and weighing 2,500 to 3,000 kilograms. They have 10

to 12 pairs of large conical teeth in each jaw (Evans 12).

Their coloration is very striking. They have black on the back and

sides and a white belly that extends as a rear-pointing lobe up the flukes

and less markedly near the head, and around the throat (15). They are also

white on the chin and underside of their flippers with a distinctive,

conspicuous white oval patch above and behind each eye. This coloration

varies depending on regional variations. Killer whales can have indistinct

gray saddles over their backs just behind their dorsal fin (Evans 16). This is

called countershading. Countershading enables the whales to be

camouflaged from their prey (Wolfe lecture). They have a stout

torpedo-shaped body with a conical-shaped head. Their flippers are large

rounded and paddle-shaped with a centrally-placed dorsal fin. The dorsal

fin is sickle-shaped in adult females, but very tall and erect in adult males.

There are some variations in morphology between regional populations but

vocal dialects vary more between pods than geographically. There is no

exact known population size. But the largest numbers are in the Antarctic

where the population is estimated at more than 160,000 (Wheelock Colege

Killer whales may be solitary or live in groups of 2 to more than 50

animals. Food items include squid, fish, skates, rays, sharks, sea turtles,

sea birds, seals, sea lions, walrus, dolphins, porpoises, and large whales

such as fin whales, humpback whales, right whales, minke whales, and

gray whales. They are even known to attack the sperm whale and blue

whale. On the Atlantic coast of South America, as well as on islands of the

Indian Ocean, killer whales have been observed lunging through the surf

and coming right onto the beach in pursuit of elephant seals and sea lions

(Holt 17). After such an attack the whales have to wriggle and slide back

into depths adequate for swimming. In captivity, killer whales eat about 45

kg of food per day but free ranging animals probably require much more.

Although these are obviously proficient and voracious hunters, killer whales

are not known to have ever attacked a human (Evans 123).

At sea they are usually seen in “pods” of 5-20, although up to 150

have been seen together at one time. Large groups probably consist of

several pods which have temporarily aggregated. Pods themselves appear

very stable for many years, with little emigration or immigration (124).

They are highly cooperative and the group functions as a unit when

hunting, making these delphinids extremely efficient predators. Groups

usually contain adults of both sexes but sometimes females with young will

Although much research has focused on killer whale pods around

Vancouver Island and on the mainland coast, very little is known about the

whales often found in the Queen Charlotte Islands, known as “offshore”

killer whales. This separate population of killer whales appears to share

similar behaviors and the fish-eating lifestyle particular to resident whales

but appear to maintain an offshore distribution and are unique in their

vocal dialects — indicating they’re unrelated to any transient or resident

pod. Offshore whales tend to be seen in large groups of 30 to 60, and are

seldom seen in protected coastal waters. At present, there are limited

details concerning the offshore population’s range, social organization or

life history. However, we hope that it will be possible to fill in many of these

gaps in the future, and to determine if and how these offshore whales

might be related to the well-known inshore resident and transient

The reproductive habits of these whales are poorly known. The males

may mate with more than one female and mating may occur throughout

the year, although most calves seem to appear in autumn or winter in

shallow waters. The female gives birth to a single calf 16 or 17 months

after mating. The calf is nursed for 14 to 18 months (Anheiser Busch 16).

Calves are approximately 2.4 m long at birth and reach sexual maturity

when 4.9-6.1 m in length. Groups of killer whales seem to be remarkably

stable, with males and females staying in their natal pods, or groups, for

life. Consequently, researchers believe that, to keep inbreeding to a

minimum, mating does not occur between members of the same pod as

often as it does between members of different pods (Holt 12).

Like the complex social organizations in which they live, killer whales

also have very distinct and complex methods of communicating. Vocal

variations of resident, transient and offshore killer whales have identified

distinctive dialects that are used to recognize particular groups of whales

and relationships between groups and populations (Knight 10).

Killer whales use echolocation to gather information about their

surroundings. They send out high-frequency clicks that bounce off prey

and other objects and they interpret the returning echoes. Killer whales

communicate by means of rapid-fire click trains that sound like rasps and

screams, although when they are on the prowl for marine mammals, which

have acute underwater hearing, they can be silent for hours at a time.

Other sounds such as squeaks, squawks and screams are sounds used for

social contact within and between groups of whales. These sounds, which

are specific to a single group of whales, make up each group’s dialect (Holt

Killer Whales, like all animals, have their own specific niche, or job in

their ecosystem. They are top predators. Their job is to weed out and

hunt the sick or weak animals. This process allows a species to thrive. If

the sick and weak are allowed to live, then reproduce, they pass on their

sickness or weakness to their young, thus making the entire population

weaker. This demonstrates “Nature’s Multiple Choice Question: a)Move

b)Adapt c)Die.” These whales are believed by some scientists to have

evolved from land mammals (Wolfe Lecture).

We do not use these whales for any purposes like food or medicine,

although they used to be hunted along with humpback whales and Pseudo

Orcas, or false Killer whales for oil and blubber. We do however, capture

these whales to perform in Marine Theme Parks, and in some, like Sea

World, we use them to educate the public (Killer Whale 8). Killer whales

have no natural enemies, their only enemy is man (Wolfe).

I chose this animal because ever since I was little, I have been

fascinated with these whales. I remember my first time going to Sea World

when I was 7 years old. I saw this giant creature doing all sorts of tricks

and I was mesmerized. Back then you didn’t learn about the whales, you

just watched the tricks. Now, over the years, the shows have become more

and more focused on education. I wanted to learn more, which is why I

Man doesn’t know enough about these whales. They are still

fascinating animal lovers, especially since the making of the movie “Free

Willy”. Millions of people visit parks like Sea World ever year, and learn

more about these beautiful creatures. We must continue to study them in

their natural environment and learn as much as we can.

Works Cited

Anheiser Busch. “Animal Resources.” 1998.

Evans, Peter. Whales & Dolphins. Facts On File. New York, NY. 1987.

Holt, George. “Orca.”

Knight, Tim. “Killer Whale Info and Pictures.”
mammal/whale/killerwhale01.html. 1997.

Wheelock College, Boston. “WhaleNet.”

Wolfe. Oceanography class Lectures and Handouts.

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