dolphins whales community
ORCA (KILLER WHALE)
Orcinus orca
Classification:
The orca is the apex predator of the sea and the largest member of the dolphin family.
It is highly intelligent, highly adaptable and able to communicate and coordinate hunting tactics.
Not typically a migratory species, orca ‘migrations' are principally in response to changes in favoured prey abundance and can sometimes be long, e.g between Alaska and California.
Depending on the type of social group and location, orcas will hunt fish, squid, seals, sea lions, seabirds and even whales much larger than themselves.
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Appearance:
The orca, also known as a killer whale, is distinctive in appearance with a large black body, a white underside, a white patch above and behind the eye, and a grey 'saddle patch' behind the dorsal fin.
At up to nearly 10 metres long, male orcas are larger than females and have a tall dorsal fin - up to nearly 2 metres in height.
The tall sword-shaped and strikingly visible dorsal fin makes them almost unmistakable at sea.
Female length is about 20% less and the curved dorsal fin is less than half the height of the males.
Distribution:
Orcas are found throughout the world's seas, typically in extended pods, or family groups, that share a common dialect.
Relationships with other pods can be deduced by determining the number of calls they share indicating degree of relatedness.
Pods that share no calls are in different clans or communities.
Though cosmopolitan in distribution they are most abundant in cold, temperate, coastal areas.
In general, orca populations have probably been affected by human activities to a relatively small degree when compared with other marine mammal species.
However, habitat degradation, prey depletion and pollution now threaten certain populations.
Orcas also continue to be an attraction at marine parks; orca populations in the US and Canadian Pacific Northwest, Iceland and Japan were negatively impacted from the 1960s to the 1980s by the live capture industry.
Other names:
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Killer whale
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Orca
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Maximum length:
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Male: 9.8m
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Female: 8.5m
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Calf: 2.4m
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Maximum weight:
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Male: 10,000kg
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Female: 7,500kg
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Calf: 180kg
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Diet:
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Fish (including sharks)
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Cephalopods
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Marine mammals - occasionally turtles and seabirds
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Estimated population:
50,000
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Distribution map:
