The Orca or Killer Whale (Orcinus orca), less commonly, Blackfish or Seawolf, is the largest species of the oceanic dolphin family. It is found in all the world's oceans, from the frigid Arctic and Antarctic regions to warm, tropical seas.
Orcas are versatile and opportunistic predators. Some populations feed mostly on fish, and other populations hunt marine mammals, including sea lions, seals, and even large whales. There are up to five distinct Orca types, some of which may be separate subspecies or even species. Orcas are highly social; some populations are composed of matrilineal family groups which are the most stable of any animal species.[1] The sophisticated social behaviour, hunting techniques, and vocal behaviour of Orcas have been described as manifestations of culture.[2]
Although Orcas are not an endangered species, some local populations are considered threatened or endangered due to pollution, depletion of prey species, conflicts with fishing activities and vessels, habitat loss, and whaling. Wild Orcas are usually not considered a threat to humans.[3] There have, however, been isolated reports of captive Orcas attacking their handlers at marine theme parks.[4]
The Orca is an apex predator. They are sometimes called the wolves of the sea because they hunt in packs like wolves.[16] On average, an Orca eats 227 kg (500 lb) of food each day.[17]
Orcas prey on a diverse array of species. However, specific populations show a high degree of specialization on particular prey species. For example, some populations in the Norwegian and Greenland sea specialise in herring and follow that fish's migratory path to the Norwegian coast each autumn. Other populations in the area prey on seals. In field observations of the resident whales of the northeast Pacific, salmon accounted for 96% of animals' diet, with 65% of the salmon being the large, fatty Chinook.[1] They have been observed to swim through schools of the smaller salmon species without attacking any of them. Depletion of specific prey species in an area is therefore cause for concern for the local Orca population, despite the high overall diversity of potential Orca prey.
Although resident Orcas have never been observed to eat other marine mammals, they are known to occasionally harass and kill porpoises and seals for no apparent reason.[1]
Orcas are versatile and opportunistic predators. Some populations feed mostly on fish, and other populations hunt marine mammals, including sea lions, seals, and even large whales. There are up to five distinct Orca types, some of which may be separate subspecies or even species. Orcas are highly social; some populations are composed of matrilineal family groups which are the most stable of any animal species.[1] The sophisticated social behaviour, hunting techniques, and vocal behaviour of Orcas have been described as manifestations of culture.[2]
Although Orcas are not an endangered species, some local populations are considered threatened or endangered due to pollution, depletion of prey species, conflicts with fishing activities and vessels, habitat loss, and whaling. Wild Orcas are usually not considered a threat to humans.[3] There have, however, been isolated reports of captive Orcas attacking their handlers at marine theme parks.[4]
The Orca is an apex predator. They are sometimes called the wolves of the sea because they hunt in packs like wolves.[16] On average, an Orca eats 227 kg (500 lb) of food each day.[17]
Orcas prey on a diverse array of species. However, specific populations show a high degree of specialization on particular prey species. For example, some populations in the Norwegian and Greenland sea specialise in herring and follow that fish's migratory path to the Norwegian coast each autumn. Other populations in the area prey on seals. In field observations of the resident whales of the northeast Pacific, salmon accounted for 96% of animals' diet, with 65% of the salmon being the large, fatty Chinook.[1] They have been observed to swim through schools of the smaller salmon species without attacking any of them. Depletion of specific prey species in an area is therefore cause for concern for the local Orca population, despite the high overall diversity of potential Orca prey.
Although resident Orcas have never been observed to eat other marine mammals, they are known to occasionally harass and kill porpoises and seals for no apparent reason.[1]
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