Killer whales (Orcinus orca), also referred to as the orca whale or orca, and less commonly as the blackfish, is a toothed whale belonging to the ocean dolphin family. Killer whales are found in all oceans, from the cold Arctic and Antarctic regions to tropical seas. Killer whales as a species have a different diet, although individual populations often specialize in particular types of prey. Some foods exclusively on fish, while others hunt marine mammals such as sea lions, seals, sea lions, and even large whales. Killer whales are regarded as apex predators, lack of natural predators.
Killer whales are very social, some population consisting of matrilineal family groups the most stable of any animal species. Sophisticated hunting techniques and vocal behaviors, which are often specific to a particular group and traffic generation, has been described as manifestations of culture.
IUCN when assessing the conservation status of orca as the lack of data due to the possibility that two or more types of killer whales are a separate species. Some locals are considered threatened or endangered due to prey depletion, habitat loss, pollution (by PCBs), capture for marine mammal parks, and conflicts with fisheries. At the end of 2005, the "southern resident" killer whale populations that inhabit British Columbia and Washington state waters placed on the U.S. Endangered Species list.
Wild killer whales are not considered a threat to humans, although there are cases of captives killing or injuring their handlers at marine parks. Killer whales feature strongly in mythology indigenous cultures, with their reputation ranging from becoming the human soul for the killer mercilessly.
A special customized killer whale black bear back, white chest and sides, and a white patch above and behind the eyes. Calves are born with a yellowish or orange tint, which fades to white. Have weight and strong with large dorsal fin up to 2 m (6.6 ft). At the back fin, have a gray "saddle patch" behind the dark. Antarctic killer whales may have pale gray almost white on the back. Very special adult killer whale is not usually confused with any other sea creature. When viewed from a distance, teens can be confused with other cetacean species, such as the false killer whale or Risso's dolphin. Killer whale teeth are very strong and sealed enamel. Gripping jaws are powerful tools, because the upper teeth fall into the gap between the lower teeth when the mouth is closed. Front teeth inclined slightly forward and to the outside, allowing the killer whale to withstand powerful pull motion of the prey while the middle and back teeth continue to remain in place.
Killer whales are the remaining members of the largest of the dolphin family. Men typically ranges between 6 and 8 meters (20 to 26 ft) long and weighing more than 6 tons (5.9 long tons, 6.6 short tons). Women are smaller, generally ranging from 5 to 7 m (16 to 23 feet) and weighing about 3 to 4 tons (3.0 to 3.9 long tons, from 3.3 to 4.4 short tons). The biggest killer whale on record man is 9.8 m (32 ft), weighing more than 10 tonnes (9.8 long tons, 11 short tons), while the largest female was 8.5 m (28 ft), weight 7, 5 tonnes (7.4 long tons; 8.3 short tons). Calves at birth weigh about 180 kg (400 lb) and about 2.4 m (7.9 ft) long. Large size and strength of the killer whale made among the fastest marine mammals, able to reach speeds of over 30 knots (56 km / h). Frame structure delphinid killer whale is special, but stronger. Its integumentary, unlike most dolphin species to another, marked by growing dermal layer with fasikula dense network of collagen fibers.
Killer whale pectoral fins are large and rounded, resembling paddles. Male pectoral fins are significantly larger than females. At about 1.8 m (5.9 ft) male dorsal fin is more than twice the size of her and more of a triangular shape-tall, elongated isosceles triangle-whereas hers is shorter and more curved. Men and women also have different patterns of black and white in their genital area. Sexual Dimorfisme also appears in the skull, adult males have long lower jaw of the female, and have greater occipital crest.
An individual killer whales can often be identified from the dorsal fin and saddle patch it. Variations such as nicks, scratches, and tears on the dorsal fin and the pattern of white or gray in the saddle patch are unique. Published directories contain identifying photographs and names for hundreds of North Pacific animals. Photo identification has enabled the local population of killer whales to be counted each year of the budget, and have allowed an insight into the life cycle and social structure.
White killer whales occur sporadically but rare among normal killer whales, they have been seen in the northern Bering Sea and around St. Lawrence Island, and near the Russian coast. In February 2008, a white killer whale photographed 2 miles (3.2 km) from Kanaga Volcano in the Aleutian Islands.
Killer whales have good eyesight above and below the water, good hearing and a good sense of touch. They have a very sophisticated echolocation abilities, detecting the location and characteristics of prey and other objects in their environment by emitting clicks and listening to the echo.
Killer whales are found in all oceans and most seas. Because of their large range, numbers and density, distribution arrangements difficult to compare, but they clearly prefer higher latitude and coastal areas over pelagic environments.
This systematic review shows the highest density of killer whales (> 0.40 pieces per 100 km ²) in the northeast Atlantic around the Norwegian coast, in the north Pacific along the Aleutian Islands, the Gulf of Alaska and in the Southern Ocean off the coast of Antarctica lot. They are considered "common" (from 0.20 to 0.40 individuals per 100 km ²) in the eastern Pacific along the coast of British Columbia, Washington and Oregon, in the North Atlantic Ocean around Iceland and the Faroe Islands. High density has also been reported but are not counted in the western North Pacific around the Sea of Japan, Sea of Okhotsk, Kuril Islands, Kamchatka and the Commander Islands and in the southern hemisphere off the coast of South Australia, Patagonia, off the coast of southern Brazil and the southern tip of Africa. They are reported as seasonally common in the Canadian Arctic, including Baffin Bay between Greenland and Nunavut, and around Tasmania and Macquarie Island. Information for offshore regions and tropical waters are increasingly rare, but the appearance of the area, if not always, shows the killer whale can survive in most water temperatures. They have been seen, for example, in the Mediterranean, the Arabian Sea, Gulf of Mexico and the Indian Ocean around the Seychelles.
Probably the largest population lives in Antarctic waters, where they range up to the edge of the ice layer and is believed to tour the compact ice, finding open leads like beluga whales in the Arctic. In contrast, killer whales summer seasonal guests to Arctic waters, where they do not approach the ice. With the decline of Arctic sea ice in Hudson Strait fast, their coverage has now spread deep into the northwest Atlantic.
Migration patterns are poorly understood. Each summer, the same individuals appear off the coast of British Columbia and Washington. Despite decades of research, where these animals go for the rest of this year is not yet known. Transient pods have been seen from southern Alaska to central California. Killer whale population is sometimes a visit by 160 km (100 miles) in a day, but can be seen in the general area for a month or more. Killer whale pod ranges vary from 320 residents to 1,300 kilometers (200-810 miles).
Occasionally, killer whales swim into freshwater rivers. They have been documented 100 miles (160 km) along the Columbia River in the United States. They have also been found in the Fraser River in Canada and the Horikawa River in Japan.
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