Orca
Transient Orcas near Unimak Island, eastern Aleutian Islands, Alaska Size comparison against an average human
Conservation status
Conservation Dependent
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Cetacea Suborder: Odontoceti Family: Delphinidae Genus: Orcinus Species: O. orca
Binomial name
Orcinus orca Linnaeus, 1758
Orca range (in blue)

The Orca or Killer Whale (Orcinus orca) is the largest species of the oceanic dolphin family (Delphinidae). It is found in all the world's oceans, from the frigid Arctic and Antarctic regions to warm, tropical seas. Image File history File linksMetadata Killerwhales_jumping. ... Unimak Island is the largest island in Alaskas Aleutian Islands chain. ... Image File history File links This is a lossless scalable vector image. ... The conservation status of a species is an indicator of the likelihood of that species continuing to survive either in the present day or the future. ... Image File history File links Status_iucn2. ... Conservation Dependent (LR/cd) was an IUCN category assigned to species or lower taxa which were dependent on conservation efforts to prevent the taxon becoming threatened with extinction. ... Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... “Animalia” redirects here. ... Typical Classes See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... Subclasses Subclass Allotheria* Order Docodonta (extinct) Order Multituberculata (extinct) Order Palaeoryctoides (extinct) Order Triconodonta (extinct) Order Volaticotheria (extinct) Subclass Prototheria Order Monotremata Subclass Theria Infraclass Trituberculata (extinct) Infraclass Metatheria Infraclass Eutheria Mammals are a class of vertebrate animals characterized by the production of milk in females for the nourishment of... Suborders Mysticeti Odontoceti Archaeoceti (extinct) (see text for families) The order Cetacea (IPA: , L. cetus, whale) includes whales, dolphins and porpoises. ... Families See text The toothed whales (systematic name Odontoceti) form a suborder of the cetaceans. ... Genera See text Oceanic dolphins are the members of the Delphinidae family of cetaceans. ... In biology, binomial nomenclature is the formal method of naming species. ... Carolus Linnaeus, also known after his ennoblement as  , (May 23, 1707[1] – January 10, 1778), was a Swedish botanist, physician and zoologist[2] who laid the foundations for the modern scheme of nomenclature. ... Download high resolution version (1357x628, 39 KB) (C) Pcb21, 2004; Vardion, 2003. ... Genera See text. ... In biological classification, family (Latin: familia, plural familiae) is 1) a rank or 2) a taxon in that rank. ... Genera See text Oceanic dolphins are the members of the Delphinidae family of cetaceans. ...

Orcas are versatile predators with some populations feeding mostly on fish and other populations on marine mammals, including sea lions, seals, and 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. This snapping turtle is trying to make a meal of a Canada goose, but the goose is too wary. ... A marine mammal is a mammal that is primarily ocean-dwelling or depends on the ocean for its food. ... Genera Eumetopias Zalophus Otaria Neophoca Phocarctos Hundreds of California Sea Lions sunbathing on Pier 39 in San Francisco. ... Genera Monachus (Monk Seals) Mirounga (Elephant Seal) Lobodon (Crabeater Seals) Leptonychotes Hydrurga (Leopard Seals) Ommatophoca Erignathus (Bearded Seals) Phoca Halichoerus (Grey Seals) Cystophora (Hooded Seals) The true seals or earless seals are one of the three main groups of mammals within the seal suborder, Pinnipedia. ... In zoology, as in other branches of biology, subspecies is the rank immediately subordinate to a species. ... In biology, a species is one of the basic units of biodiversity. ... A social animal is a loosely defined term for an organism that is highly interactive with other members of its species to the point of having a recognizable and distinct society. ... Matrilineality is a system in which one belongs to ones mothers lineage; it may also involve the inheritance of property or titles through the female line. ... Culture (from the Latin cultura stemming from colere, meaning to cultivate), generally refers to patterns of human activity and the symbolic structures that give such activity significance. ...

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.^[2] There have, however, been isolated reports of captive Orcas attacking their handlers at marine theme parks.^[3] The Siberian Tiger, a subspecies of tiger. ... Marineland of Florida, USA — dolphin show, 1964. ...

Taxonomy and evolution

The Orca is the sole species in the genus Orcinus. It is one of thirty-five species in the dolphin family. Like the Sperm Whale genus Physeter, Orcinus is a genus with a single, abundant species. Thus, paleontologists believe that the Orca is a prime candidate to have an anagenetic evolutionary history, forming descendant species from ancestral species without splitting of the lineage. If true, this would make the Orca one of the oldest dolphin species. However, it is unlikely to be as old as the family itself, which is believed to date back at least five million years. Genera See article below. ... Binomial name Physeter macrocephalus Linnaeus, 1758 Sperm Whale range (in blue) The Sperm Whale (Physeter macrocephalus) is the largest of all toothed whales and is the largest toothed animal alive, measuring up to 18 metres (60 ft) long. ... A paleontologist carefully chips rock from a column of dinosaur vertebrae. ... Anagenetic evolution refers to the evolution of an ancestral species to a descendant species without a split of lineage. ... The Pliocene epoch (spelled Pleiocene in some older texts) is the period in the geologic timescale that extends from 5. ...

However, there are at least three to five types of Orcas that are distinct enough to be considered different races, subspecies, or possibly even species. In the 1970s and 1980s, research off the west coast of Canada and the United States identified the following three types: RACE, 5 RACE or Rapid Amplification of cDNA Ends, is a molecular biology technique used to amplify the 5 ends of cDNA by a special PCR reaction. ... In zoology, as in other branches of biology, subspecies is the rank immediately subordinate to a species. ... In biology, a species is one of the basic units of biodiversity. ...

• Resident: These are the most commonly sighted of the three populations in the coastal waters of the northeast Pacific, including Puget Sound. The resident Orcas' diet consists primarily of fish and sometimes squid and they live in complex and cohesive family groups known as pods. Female residents characteristically have a rounded dorsal fin tip that terminates in a sharp corner. They are known to visit certain areas consistently.
• Transient: The diet of these Orcas consists almost exclusively of marine mammals; they do not eat fish. Transients generally travel in small groups, usually of two to six animals. Unlike residents, transients may not always stay together as a family unit. Female transients are characterized by dorsal fins that are more triangular and pointed than those of residents. Transients travel on extremely unpredictable routes; they may be seen once in an area and never be seen after, or return 10 years later.
• Offshore: These Orcas cruise the open oceans and feed primarily on fish, sharks and turtles. They have been seen travelling in groups of up to 60 animals. Currently there is little known about the habits of this population, but they can be distinguished genetically from the residents and transients. Female offshores are characterized by dorsal fin tips that are continuously rounded. Offshores also seem smaller than the two other types. Offshores live only in open seas, hence the name, which makes them difficult to study.

Type C Orcas in the Ross Sea. The eye patch slants forward.

Orca populations in other parts of the world have not been as well-studied. However, there appears to be a correlation between a population's diet and its social behaviour. Fish-eating Orcas in Alaska and Norway have also been observed to have resident-like social structures. Mammal-eating Orcas in Argentina and the Crozet Islands have been observed to behave more like transients.^[1] Suborders Myopsina Oegopsina Squid are a large, diverse group of marine cephalopods. ... A marine mammal is a mammal that is primarily ocean-dwelling or depends on the ocean for its food. ... A giant grouper at the Georgia Aquarium Fish are aquatic vertebrates that are typically cold-blooded; covered with scales, and equipped with two sets of paired fins and several unpaired fins. ... Orders Carcharhiniformes Heterodontiformes Hexanchiformes Lamniformes Orectolobiformes Pristiophoriformes Squaliformes Squatiniformes Symmoriida(extinct) Sharks (superorder Selachimorpha) are fish with a full cartilaginous skeleton[1] and a streamlined body. ... blue: sea turtles, black: land turtles Suborders Cryptodira Pleurodira See text for families. ... Dorsal fin of an orca A dorsal fin is a fin located on the backs of fishes, whales, dolphins, and porpoises, as well as the (extinct) ichthyosaurs. ... Image File history File links Size of this preview: 450 × 600 pixel Image in higher resolution (1200 × 1600 pixel, file size: 212 KB, MIME type: image/jpeg) Mother-calf pair of Type C killer whales in the Ross Sea. ... Image File history File links Size of this preview: 450 × 600 pixel Image in higher resolution (1200 × 1600 pixel, file size: 212 KB, MIME type: image/jpeg) Mother-calf pair of Type C killer whales in the Ross Sea. ... Map of Antarctica (click to enlarge) Ice in the Ross Sea, Antarctica The Ross Sea is a deep bay of the Southern Ocean in Antarctica between Victoria Land and Marie Byrd Land. ... Official language(s) none Capital Juneau Largest city Anchorage Area  Ranked 1st  - Total 663,267 sq mi (1,717,855 km²)  - Width 808 miles (1,300 km)  - Length 1,479 miles (2,380 km)  - % water 13. ... Orthographic projection centred over the Iles Crozet The Crozet Islands (French: ÃŽles Crozet or officially Archipel Crozet) are a sub-antarctic archipelago of small islands in the southern Indian Ocean, part of the French Southern Territories. ...

Transient and resident Orcas live in the same areas, but avoid each other. The name "transient" originated from the belief that these Orcas were outcasts from larger resident pods. Researchers later discovered that transients are not born into resident pods, or vice-versa. The evolutionary split between the two groups is believed to have begun two million years ago.^[4] Recent genetic research has found that the types have not interbred for up to 10,000 years.^[5]

Three Orca types have recently been documented in the Antarctic. Greek ἀνταρκτικός, opposite the arctic) is a continent surrounding the Earths South Pole. ...

• Type A looks like a "typical" Orca, living in open water and feeding mostly on Minke Whales.
• Type B is smaller than Type A. It has a large white eyepatch and a patch of grey colouring on its back, called a dorsal cape. It feeds mostly on seals.
• Type C is the smallest type and lives in larger groups than any other type of Orca. Its eyepatch is distinctively slanted forwards, rather than parallel to the body axis. Like Type B, it has a dorsal cape. Its only prey observed so far is the Antarctic toothfish.

Type B and C Orcas live close to the Antarctic ice pack, and diatoms in these waters may be responsible for the yellowish colouring of both types. Research is ongoing as to whether Type B and C Orcas are different species.^[6][7] Binomial name Balaenoptera acutorostrata Lacepede, 1804 Balaenoptera bonaerensis Burmeister, 1867 Minke Whale range Antarctic Minke Whale range Dwarf Minke Whale range The Minke Whale or Lesser Rorqual is a marine mammal belonging to the suborder of baleen whales. ... Families Odobenidae Otariidae Phocidae Pinnipeds (fin-feet, lit. ... Binomial name Dissostichus mawsoni Norman, 1937 The Antarctic Cod, fish of the Nototheniidae family that includes Mawsons cod (Dissostichus mawsoni), is famous for producing antifreeze protein that allows it to hide just under the Antarctic ice. ... Diatoms are the most common of the eukaryotic algae. ...

Description

The dorsal fin and saddle patch of a resident Orca in the northeastern Pacific Ocean. It may be either an adult female, or a juvenile of either sex.

Orcas are distinctively marked, with a black back, white chest and sides, and a white patch above and behind the eye. Calves are born with a yellowish or orange tint, which fades to white. Orcas have a heavy and stocky body and a large dorsal fin with a dark grey "saddle patch" at the fin's rear. Males can be up to 9.5 m long (31 ft) and weigh in excess of 6 tonnes; it has been reported that especially large males have reached nearer 8 tonnes. Females are smaller, reaching up to 8.5 m (28 ft) and a weight of about 5 tonnes. The longest Orca ever recorded was a male from Washington state, measuring 9.8 m (32 ft). Calves at birth weigh about 180 kg and are about 2.4 m long (8 ft). The Orca's large size and strength make them the fastest marine mammals, often reaching speeds in excess of 56 km/h (35mph). Dorsal Fin or the orca whale, thanks to the NOAA Photo Library http://www. ... Dorsal Fin or the orca whale, thanks to the NOAA Photo Library http://www. ... Dorsal fin of an orca A dorsal fin is a fin located on the backs of fishes, whales, dolphins, and porpoises, as well as the (extinct) ichthyosaurs. ... A tonne or metric ton (symbol t), sometimes referred to as a metric tonne, is a measurement of mass equal to 1,000 kilograms. ...

Unlike most dolphins, the pectoral fin of an Orca is large and rounded — more of a paddle than other dolphin species. Males have significantly larger pectoral fins than females. At about 1.8 m (6 ft), the dorsal fin of the male is more than twice the size of the female's, and is more of a triangle shape — a tall, elongated isosceles triangle, whereas the dorsal fin of the female is shorter and generally more curved. Fish anatomy is primarily governed by the physical characteristics of water, which is much denser than air, holds a relatively small amount of dissolved oxygen, and absorbs light more than does air. ...

Adult male Orcas are very distinctive and are unlikely to be confused with any other sea creature. When seen from a distance in temperate waters, adult females and juveniles can be confused with various other species, such as the False Killer Whale or Risso's Dolphin. Binomial name Pseudorca crassidens (Owen, 1846) False Killer Whale range The Lovely Whale (Pseudorca crassidens) is a cetacean and one of the larger members of the oceanic dolphin family (Delphinidae). ... Binomial name Grampus griseus (G. Cuvier, 1812) Rissos Dolphin range The Rissos Dolphin (Grampus griseus) is the only species of dolphin in the genus Grampus. ...

An Orca skull.

Individual Orcas can be identified from a good photograph of the animal's dorsal fin and saddle patch, taken when it surfaces. Variations such as nicks, scratches, and tears on the dorsal fin, and the pattern of white or grey in the saddle patch, are sufficient to distinguish Orcas from each other. For the well-studied Orcas of the northeast Pacific, catalogues have been published with the photograph and name of each Orca. Photo-identification has enabled the local population of Orcas to be counted each year rather than estimated, and has enabled great insight into Orca lifecycles and social structures. Image File history File links Download high resolution version (2489x1285, 631 KB) Orcinus orca Sceletal head of a Orca Photo taken by User BS Thurner Hof Feb 2005 Museum Koenig, Bonn File links The following pages on the English Wikipedia link to this file (pages on other projects are not... Image File history File links Download high resolution version (2489x1285, 631 KB) Orcinus orca Sceletal head of a Orca Photo taken by User BS Thurner Hof Feb 2005 Museum Koenig, Bonn File links The following pages on the English Wikipedia link to this file (pages on other projects are not... It has been suggested that temporal fenestra be merged into this article or section. ...

Lifecycle

Females become mature at around 15 years of age. Then they have periods of polyestrous cycling with non-cycling periods of between three and sixteen months. The gestation period varies from fifteen to eighteen months. Mothers calve, with a single offspring, about once every five years. In analyzed resident pods, birth occurs at any time of year, with the most popular months being those in winter. Newborn mortality is very high — one survey suggested that nearly half of all calves fail to reach the age of six months. Calves nurse for up to two years, but will start to take solid food at about twelve months. All resident Orca pod members, including males of all ages, participate in the care of young whales.^[4] The estrus cycle (also Å“strus or estrous cycle) refers to the recurring physiologic changes that are induced by reproductive hormones in most mammalian placental females (humans and great apes are the only mammals who undergo a menstrual cycle instead). ... The Gestation period in a viviparous animal refers to the length of its pregnancy. ... A glass of cows milk. ...

Cows breed until the age of 40, meaning that on average they raise five offspring. Typically, females live to the age of fifty, but may survive well into their eighties or nineties in exceptional cases. Males become sexually mature at the age of 15, but do not typically reproduce until age 21. Males live to about 45 on average, and close to 90 in exceptional cases.^[8]

Distribution

Orcas are found in all oceans and most seas, including (unusually for cetaceans) the Mediterranean and Arabian seas. However, they prefer cooler temperate and polar regions. Although sometimes spotted in deep water, coastal areas are generally preferred to pelagic environments. Composite satellite image of the Mediterranean Sea. ... Map of the Arabian Sea. ... For other uses of the word pole, see Pole (disambiguation). ... This is a scale diagram of the layers of the pelagic zone. ...

The Orca is particularly highly concentrated in the north-east Pacific Basin, where Canada curves into Alaska, off the coast of Iceland and off the coast of northern Norway. They are regularly sighted in Antarctic waters right up to the ice-pack and are believed to venture under the pack and survive breathing in air pockets like the beluga does. In the Arctic, however, the species is rarely seen in winter, as it does not approach the ice pack. It does visit these waters during summer. For other meanings of Pacific, see Pacific (disambiguation). ... Official language(s) none Capital Juneau Largest city Anchorage Area  Ranked 1st  - Total 663,267 sq mi (1,717,855 km²)  - Width 808 miles (1,300 km)  - Length 1,479 miles (2,380 km)  - % water 13. ... In norwegian: Nord-Norge meaning Northern Norway. ... For other uses, see Antarctica (disambiguation). ... Polar ice consists of sea ice formed from the freezing of sea water, as well as ice sheets and glaciers formed from the accumulation and compaction of falling snow. ... Binomial name Delphinapterus leucas (Pallas, 1776) Beluga range This article is about the whale. ...

Information for off-shore regions and tropical waters is more scarce but widespread, if not frequent, sightings indicate that the Orca can survive in most water temperatures. Sightings are rare in Indonesian and Philippine waters. No estimate for the total worldwide population exists. Local estimates include 70–80,000 in the Antarctic, 8,000 in the tropical Pacific (although tropical waters are not the Orca's preferred environment, the sheer size of this area — 19 million square kilometres — means there are thousands of Orcas), up to 2,000 off Japan, 1,500 off the cooler north-east Pacific and 1,500 off Norway. Adding very rough estimates for unsurveyed areas, the total population could be around 100,000.

With the rapid decline of Arctic sea ice in the Hudson Strait, the range of Orcas has now extended into the far northern waters of Canada. Through the 1990s, Orcas were sighted in western Hudson Bay at a rate of six per decade; sightings rose to more than 30 between 2001–2006.^[9] NOAA Projected arctic changes Polar ice packs are large areas of pack ice formed from seawater in the Earths polar regions, known as polar ice caps: the Arctic ice pack (or Arctic ice cap) of the Arctic Ocean and the Antarctic ice pack of the Southern Ocean, a part... Hudson Strait is a strait connecting Hudson Bay to the Atlantic Ocean, running in an west-east direction. ... Hudson Bay, Canada. ...

The migration patterns of Orcas are poorly understood. Each summer, the same resident Orcas appear off the coasts of British Columbia and Washington State. After decades of research, it is still unknown where these animals go for the rest of the year.

Diet

Resident (fish-eating) Orcas. The curved dorsal fins are typical of resident females.

The Orca is an apex predator. They are sometimes called the wolves of the sea because they hunt in packs like wolves^{[citation needed]}. On average, an Orca eats 227 kg (500 lb) of food each day.^[10] The array of species on which Orcas prey is diverse. Image File history File links Orca_pod_southern_residents. ... Image File history File links Orca_pod_southern_residents. ... This article or section does not cite any references or sources. ... Wolf Wolf Man Mount Wolf Wolf Prizes Wolf Spider Wolf 424 Wolf 359 Wolf Point Wolf-herring Frank Wolf Friedrich Wolf Friedrich August Wolf Hugo Wolf Johannes Wolf Julius Wolf Max Franz Joseph Cornelius Wolf Maximilian Wolf Rudolf Wolf Thomas Wolf As Name Wolf Breidenbach Wolf Hirshorn Other The call...

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. Species Clupea alba Clupea bentincki Clupea caspiopontica Clupea chrysotaenia Clupea elongata Clupea halec Clupea harengus Clupea inermis Clupea leachii Clupea lineolata Clupea minima Clupea mirabilis Clupea pallasii Clupea sardinacaroli Clupea sulcata Herrings are small oily fish of the genus Clupea found in the shallow, temperate waters of the North Atlantic... This article or section does not cite any references or sources. ... Illustration of a male Coho Salmon The Chinook or King Salmon is the largest salmon in North America and can grow to 1. ... Binomial name Oncorhynchus tshawytscha (Walbaum, 1792) The Chinook salmon (Oncorhynchus tshawytscha) (derived from Russian чавыча), is a species of anadromous fish in the salmon family. ...

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]

Fish and other cold-blooded prey

Fish-eating Orcas prey on 30 species of fish, particularly salmon (including Chinook and Coho), herring, and tuna. Basking sharks, oceanic whitetip sharks, and occasionally even great white sharks are taken for their nutrient-rich livers. In New Zealand killer whales have been observed hunting stingrays as well. Cephalopods, such as octopuses and a wide range of squids, are also targets. A giant grouper at the Georgia Aquarium Fish are aquatic vertebrates that are typically cold-blooded; covered with scales, and equipped with two sets of paired fins and several unpaired fins. ... Illustration of a male Coho Salmon The Chinook or King Salmon is the largest salmon in North America and can grow to 1. ... Binomial name Oncorhynchus tshawytscha (Walbaum, 1792) The Chinook salmon (Oncorhynchus tshawytscha) (derived from Russian чавыча), is a species of anadromous fish in the salmon family. ... Binomial name Oncorhynchus kisutch (Walbaum, 1792) The Coho salmon (Oncorhynchus kisutch - from the Russian Kisutch - кижуч) is a species of anadromous fish in the salmon family. ... A shoal of skipjack tuna Tuna are several species of ocean-dwelling fish in the family Scombridae, mostly in the genus Thunnus. ... Binomial name Cetorhinus maximus (Gunnerus, 1765) The Basking Shark (Cetorhinus maximus), also known as the Bone Shark, is the second largest fish alive, after the Whale Shark. ... Binomial name Carcharhinus longimanus (Poey, 1861) Range of oceanic whitetip shark The oceanic whitetip shark, Carcharhinus longimanus, is a large pelagic shark of tropical and warm temperate seas. ... Binomial name Carcharodon carcharias (Linnaeus, 1758) Range (in blue) The great white shark, Carcharodon carcharias, also known as white pointer, white shark, or white death, is an exceptionally large lamniforme shark found in coastal surface waters in all major oceans. ... Orders Subclass Nautiloidea †Plectronocerida †Ellesmerocerida †Actinocerida †Pseudorthocerida †Endocerida †Tarphycerida †Oncocerida †Discosorida Nautilida †Orthocerida †Ascocerida †Bactritida Subclass †Ammonoidea †Goniatitida †Ceratitida †Ammonitida Subclass Coleoidea †Belemnoidea †Aulacocerida †Belemnitida †Hematitida †Phragmoteuthida Neocoleoidea (most living cephalopods) ?†Boletzkyida Sepiida Sepiolida Spirulida Teuthida Octopoda Vampyromorphida The cephalopods (Greek plural (kephalópoda); head-foot) are the mollusk class... Suborders †Pohlsepia (incertae sedis) †Proteroctopus (incertae sedis) †Palaeoctopus (incertae sedis) Cirrina Incirrina Synonyms Octopoida Leach, 1817 The octopus (Greek , eight-legs) is a cephalopod of the order Octopoda that inhabits many diverse regions of the ocean, especially coral reefs. ... Suborders Myopsina Oegopsina Squid are a large, diverse group of marine cephalopods. ...

While salmon are usually hunted by a single Orca or a small group of individuals, herring are often caught using carousel feeding: the Orcas force the herring into a tight ball by releasing bursts of bubbles or flashing their white undersides. The Orcas then slap the ball with their tail flukes, either stunning or killing up to 10–15 herring with a successful slap. The herring are then eaten one at a time. Carousel feeding has only been documented in the Norwegian Orca population and with some oceanic dolphin species. This article or section does not cite any references or sources. ...

Marine mammal prey

Twenty-two cetacean species have been recorded as preyed on by Orcas, either through an examination of stomach contents, examining scarring on the prey's body, or from observing the Orcas' feeding activity. Groups of Orcas attack even larger cetaceans such as Minke Whales, Gray Whales, and very occasionally Sperm Whales or Blue Whales. Orcas generally choose to attack whales which are young or weak. However, a group of five or more Orcas may attack healthy adult whales. Suborders Mysticeti Odontoceti (see text) The order Cetacea includes whales, dolphins and porpoises. ... In anatomy, the stomach is a bean-shaped hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication. ... This article or section does not adequately cite its references or sources. ... Binomial name Balaenoptera acutorostrata Lacepede, 1804 Balaenoptera bonaerensis Burmeister, 1867 Minke Whale range Antarctic Minke Whale range Dwarf Minke Whale range The Minke Whale or Lesser Rorqual is a marine mammal belonging to the suborder of baleen whales. ... Binomial name Eschrichtius robustus Lilljeborg, 1861 Gray Whale range The Gray Whale or Grey Whale (Eschrichtius robustus), more recently called the Eastern Pacific Gray Whale, is a whale that travels between feeding and breeding grounds yearly. ... Binomial name Physeter macrocephalus Linnaeus, 1758 Sperm Whale range (in blue) The Sperm Whale (Physeter macrocephalus) is the largest of all toothed whales and is the largest toothed animal alive, measuring up to 18 metres (60 ft) long. ... Binomial name Balaenoptera musculus (Linnaeus, 1758) Blue Whale range The Blue Whale (Balaenoptera musculus) is a marine mammal belonging to the suborder of baleen whales. ...

When hunting a young whale, a group chases it and its mother until they are worn out. Eventually the Orcas manage to separate the pair and surround the young whale, preventing it from returning to the surface to breathe. Whales are typically drowned in this manner. Pods of female Sperm Whales can sometimes protect themselves against a group of Orcas by forming a protective circle around their calves with their flukes facing outwards. This formation allows them to use their powerful flukes to repel the Orcas. Hunting large whales, however takes a lot of time, usually several hours. Binomial name Physeter macrocephalus Linnaeus, 1758 Sperm Whale range (in blue) The Sperm Whale (Physeter macrocephalus) is the largest of all toothed whales and is the largest toothed animal alive, measuring up to 18 metres (60 ft) long. ...

A Harbour Seal

Orca grabbing a seal from the beach in Patagonia

Other marine mammals prey species include most species of seal and sea lion, and less frequently Walruses and Sea Otters. Orcas often use complex hunting strategies to find and subdue their prey. Sea lions are killed by head-butting or by being slapped and stunned by a tail fluke. They occasionally throw seals through the air in order to stun and kill them. Often, to avoid injury, they disable their prey before killing and eating it. This may involve throwing it in the air, slapping it with their tails, ramming it, or breaching and landing on it. Image File history File links Download high resolution version (2240x1488, 954 KB) Common Seal (Phoca vitulina) Source: Marcel Burkhard alias cele4 - http://www. ... Image File history File links Download high resolution version (2240x1488, 954 KB) Common Seal (Phoca vitulina) Source: Marcel Burkhard alias cele4 - http://www. ... Binomial name Phoca vitulina Linnaeus, 1758 Common or Harbour Seals (Phoca vitulina) are true seals of the Northern Hemisphere. ... Image File history File links OrcaSeal. ... Image File history File links OrcaSeal. ... Patagonia, as most commonly defined (in orange). ... Families Odobenidae Otariidae Phocidae Pinnipeds (fin-feet, lit. ... Genera Eumetopias Zalophus Otaria Neophoca Phocarctos Hundreds of California Sea Lions sunbathing on Pier 39 in San Francisco. ... Binomial name Odobenus rosmarus (Linnaeus, 1758) Distribution of Walrus Subspecies Walruses (Odobenus rosmarus) are large semi-aquatic mammals that live in the cold Arctic seas of the Northern Hemisphere. ... Binomial name Enhydra lutris (Linnaeus, 1758) The Sea Otter (Enhydra lutris) is a large otter native to the North Pacific, from northern Japan and Kamchatka west across the Aleutian Islands south to California. ... Head butting is a fighting technique that uses the cranium to strike an opponents face to cause injury or a knockout. ...

Some highly specialized hunting techniques have been observed. Off Argentina and the Crozet Islands, Orcas feed on South American sea lion and elephant seal pups in shallow water; even beaching themselves temporarily. Beaching, usually fatal to whales, is not an instinctive behaviour. Adult Orcas have been observed to teach the younger whales the skills of hunting in shallow water. Off Argentina, adults pull seals off the shoreline for younger whales to recapture. Off the Crozet Islands, mothers have been seen pushing their calves onto the beach, waiting to pull the youngster back if needed.^[4] Orthographic projection centred over the Iles Crozet The Crozet Islands (French: ÃŽles Crozet or officially Archipel Crozet) are a sub-antarctic archipelago of small islands in the southern Indian Ocean, part of the French Southern Territories. ... Binomial name Otaria flavescens (Shaw, 1800) The South American Sea Lion (Otaria flavescens, previously Otaria bryonia) is a sea lion found on the Chilean, Peruvian, Uruguayan and Argentine coasts. ... Species M. leonina M. angustirostris Elephant seals are large, oceangoing mammals in the genus Mirounga, in the earless seal family (Phocidae). ... A mass stranding of Pilot Whales A beached whale is a whale which has become stranded on land, usually on a beach. ...

Another technique for capturing seals is known as wave-hunting: Orcas spy-hop to locate seals resting on ice floes, and then create waves by swimming together in groups to wash over the floe. This causes the seal to be thrown into the water where another Orca waits to kill it. This behaviour has only been recorded a few times and it is not known how often it occurs. The most recent recorded instance in April 2006 ended with the group of Orcas actually returning the seal to the ice floe after they had shown the younger animals how to properly perform the technique. Whales exhibit various types of physical behaviour when they surface. ...

Birds

Several species of bird are also preyed upon, including penguins, cormorants and sea gulls. A captive Orca in Friendship Cove discovered that it could regurgitate fish onto the surface, attracting sea gulls, and then eat them. Other Orcas then learned the behaviour by example.^[11] Orcas at Sea World California have also been observed hunting birds.^[12] Modern genera Aptenodytes Eudyptes Eudyptula Megadyptes Pygoscelis Spheniscus For prehistoric genera, see Systematics Some penguins are curious. ... For other uses, see Cormorant (disambiguation). ... Genera Pagophila Larus Rissa Creagus Xema Rhodostethia Gulls are seabirds in the family Laridae and subfamily Lari. ... Marinoland is a themed amusement and animal exhibition park in the city of Niagara Falls, Ontario, Canada. ...

Behavior

Orcas often raise their bodies out of the water in a behaviour called spyhopping.

The day-to-day behaviour of Orcas is generally divided into four activities: foraging, travelling, resting and socializing. Orcas are generally enthusiastic in their socializing, engaging in behaviours such as breaching, spyhopping, and tail-slapping. Image File history File links Download high resolution version (1180x850, 307 KB)A spyhopping Orca in the Ross Sea. ... Image File history File links Download high resolution version (1180x850, 307 KB)A spyhopping Orca in the Ross Sea. ... Whales exhibit various types of physical behaviour when they surface. ... Whales exhibit various types of physical behaviour when they surface. ... Whales exhibit various types of physical behaviour when they surface. ...

Resident Orcas can also be seen swimming with porpoises, other dolphins, seals, and sea lions, which are common prey for transient Orcas. Resident Orcas are continually on the move, sometimes travelling as much as 160 km (100 miles) in a day, but may be seen in a general area for a month or more. Range for resident Orca pods may be as much as 1300 km (800 miles) or as little as 320 km (200 miles). Genera Neophocaena Phocoena - Harbor porpoise Phocoenoides - Dalls porpoise The porpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. ... Genera See article below. ... Genera Monachus (Monk Seals) Mirounga (Elephant Seal) Lobodon (Crabeater Seals) Leptonychotes Hydrurga (Leopard Seals) Ommatophoca Erignathus (Bearded Seals) Phoca Halichoerus (Grey Seals) Cystophora (Hooded Seals) The true seals or earless seals are one of the three main groups of mammals within the seal suborder, Pinnipedia. ... Genera Eumetopias Zalophus Otaria Neophoca Phocarctos Hundreds of California Sea Lions sunbathing on Pier 39 in San Francisco. ...

Social structure of resident Orca communities

Fish-eating Orcas in the North Pacific have a complex but extremely stable system of social grouping. Unlike any other mammal species whose social structure is known, resident Orcas of both genders live with their mothers for their entire lives. Therefore, Orca societies are based around matrilines consisting of a single female (the matriarch) and her descendants. The sons and daughters of the matriarch form part of the line, as do the sons and daughters of those daughters. The average size of a matriline is nine animals. Matrilineality is a system in which one belongs to ones mothers lineage; it may also involve the inheritance of property or titles through the female line. ... ...

Because females can live for up to ninety years, it is not uncommon for four or even five generations to travel together. These matrilineal groups are highly stable. Individuals split off from their matrilineal group only for up to a few hours at a time, in order to mate or forage. No permanent casting-out of an individual from a matriline has ever been recorded.

Closely-related matrilines form loose aggregations called pods, consisting on average of about 18 animals. All members of a pod use a similar set of calls, known as a dialect. Unlike matrilines, pods may split apart for days or weeks at a time in order to forage. Orcas within a pod do not interbreed; mating occurs only between members of different pods.

Orcas, like this one spotted near Alaska, commonly breach, often lifting their entire body out of the water.

Resident pods have up to 50 or more members. Occasionally, several pods join to form "superpods," sometimes with more than 150 animals. Taken from German Wikipedia, who took it from the NOAA, (US Gov employee photo, thus public domain). ... Whales exhibit various types of behaviour when they surface. ...

The next level of grouping is the clan. A clan consists of pods which have a similar dialect. Again the relationship between pods appears to be genealogical, consisting of fragments of families with a common heritage on the maternal side. Different clans can occupy the same geographical area; pods from different clans are often observed travelling together. When resident pods come together to travel as a clan, they greet each other by forming two parallel lines akin to a face-off before mingling with each other. Parallel is a term in geometry and in everyday life that refers to a property in Euclidean space of two or more lines or planes, or a combination of these. ...

The final layer of association, perhaps more arbitrary and devised by humans rather than the other very natural divisions, is called the community and is loosely defined as the set of clans that are regularly seen mixing with each other. Communities do not follow discernible familial or vocal patterns.^[13]

Transient groups are generally smaller because, although they too are based on matrilines, some male and female offspring eventually disperse from the maternal group. However, transient groups still have a loose connection defined by their dialect.

Vocal behavior

See also: Whale song

As with other dolphins, Orcas are highly vocal. They produce a variety of clicks and whistles that are used for communication and echolocation. The vocalization types vary with activity. While resting they are much quieter, merely emitting an occasional call that is distinct from those heard when engaging in more active behaviour. Killer whale. ... Software development stages In computer programming, development stage terminology expresses how the development of a piece of software has progressed and how much further development it may require. ... Killer whale simple. ... Software development stages In computer programming, development stage terminology expresses how the development of a piece of software has progressed and how much further development it may require. ... Killer whale residents broadband. ... Software development stages In computer programming, development stage terminology expresses how the development of a piece of software has progressed and how much further development it may require. ... Humpback whales are well known for their songs Whale song is the sound made by whales to communicate. ... Echolocation, also called Biosonar, is the biological sonar used by several mammals such as bats (not all of them), dolphins and whales. ...

Fish-eating resident groups of Orcas in the northeast Pacific tend to be much more vocal than transient groups living in the same waters. Resident Orcas feed on fish, particularly salmon, a prey with poor underwater hearing that cannot detect Orca calls at any significant distance. Transient Orcas on the other hand feed mainly on marine mammals and occasionally on seabirds. Because all marine mammals have excellent underwater hearing, transients probably remain silent for much of the time to avoid detection by their acoustically-sensitive prey. They sometimes use a single click (called a cryptic click) rather than the long train of clicks observed in other populations. On the other hand, residents will make sounds to identify themselves when they are approaching other sea mammals. Illustration of a male Coho Salmon The Chinook or King Salmon is the largest salmon in North America and can grow to 1. ...

Resident pods have group-specific dialects. Each pod has its own vocal repertoire or set of particular stereotyped underwater calls (call types). Every member of the pod seems to know all the call types of the pod, so it is not possible to identify a single animal using voice alone. A particular call type might be used by only one group or shared among several.

The number of call types shared by two groups appears to be a function of their genealogical relatedness rather than their geographical distance. Two groups that share a common set of ancestors but have grown apart in distance are likely to have a similar set of call types, indicating that calls are a learned behaviour.

Orca mothers have been observed training their young in the pod's dialect. The mother uses a simplified version of the pod's dialect when training a calf; a sort of baby-talk. This suggests that Orca vocalization has a learned basis in addition to an instinctual one. The suckling of a newborn at its mothers nipple is an example of an instinctive behavior. ...

Intelligence

Main article: Cetacean intelligence

Orcas are well known for their mental capabilities. Studies have indicated that an Orca has an outstanding memory, perhaps even photographic. Cetacean intelligence denotes the cognitive capabilities of the cetacean order of mammals and especially the various species of dolphin. ...

The Orca's use of dialects and the passing of other learned behaviours from generation to generation has been described as a form of culture. The paper Culture in Whales and Dolphins,^[14] goes as far as to say, "The complex and stable vocal and behavioural cultures of sympatric groups of killer whales (Orcinus orca) appear to have no parallel outside humans and represent an independent evolution of cultural faculties. Culture (from the Latin cultura stemming from colere, meaning to cultivate), generally refers to patterns of human activity and the symbolic structures that give such activity significance. ...

Conservation

An adult female and her calf

Environmental degradation, depletion of prey species, conflicts with fishing activities, and habitat degradation are currently the most significant threats to Orcas worldwide.^[2][1] Image File history File links Orca_mother_calf. ... Image File history File links Orca_mother_calf. ... Fishing is the activity of hunting for fish by hooking, trapping, or gathering. ...

Like other animals at the highest trophic levels of the food chain, the Orca is particularly susceptible to poisoning via accumulation of Polychlorinated biphenyls (PCBs) in the body. A survey of animals off the Washington coast found that PCB levels in Orcas were higher than those in harbour seals in Europe that have been sickened by the chemical. Samples from the blubber of Orcas in the Norwegian Arctic show higher levels of PCBs, pesticides and brominated flame-retardants than in Polar Bears. In ecology, the trophic level (Greek trophē, food) is the position that an organism occupies in a food chain - what it eats, and what eats it. ... This article or section does not cite any references or sources. ... It has been suggested that this article or section be merged with Polychlorinated biphenyls (PCBs). ... This article deals with the U.S. state. ... Binomial name Phoca vitulina Linnaeus, 1758 Common or Harbour Seals (Phoca vitulina) are true seals of the Northern Hemisphere. ... World map showing the location of Europe. ... The red line indicates the 10°C isotherm in July, commonly used to define the Arctic region border Satellite image of the Arctic surface The Arctic is the region around the Earths North Pole, opposite the Antarctic region around the South Pole. ... A cropduster spreading pesticide. ... Brominated flame-retardants are produced synthetically in 70 variants with very varying chemical properties. ... Binomial name Ursus maritimus Phipps, 1774 Polar bear range Synonyms Thalarctos maritimus The polar bear (Ursus maritimus), also known as the white bear, northern bear, sea bear, ice bear or nanuq in some Inuit languages, is a species of bear that is native to the Arctic and the apex predator...

Stocks of most species of salmon, a main food source for resident Orcas in the northeast Pacific, have declined dramatically in recent years. On the west coast of Alaska and the Aleutian Islands, populations of seals and sea lions have also undergone a major decline.^[1] If food is scarce, Orcas must draw from their blubber for energy, which further magnifies the effects of pollutants. In 2005, the United States government listed the Southern Resident community of Orcas as an endangered population under the Endangered Species Act. The Southern Resident community comprises three pods which spend most of the year in the Georgia and Haro Straits and Puget Sound in British Columbia and Washington state. These Orcas do not breed outside of their community, which was previously estimated at around 200 animals and had shrunk to around 90.^[15] Official language(s) none Capital Juneau Largest city Anchorage Area  Ranked 1st  - Total 663,267 sq mi (1,717,855 km²)  - Width 808 miles (1,300 km)  - Length 1,479 miles (2,380 km)  - % water 13. ... Aleutians seen from space The Aleutian Islands (possibly from Chukchi aliat, island) are a chain of more than 300 small volcanic islands forming an island arc in the Northern Pacific Ocean, occupying an area of 6,821 sq mi (17,666 km²) and extending about 1,200 mi (1,900... Remains of seventeenth century blubber cauldrons at the abandoned Dutch settlement of Smeerenburg in Svalbard, Norway This article is about the body tissue. ... This article or section is in need of attention from an expert on the subject. ... Puget Sound For the liberal arts university located in this region, see University of Puget Sound. ... Motto: Splendor Sine Occasu (Latin: Splendour without diminishment) Capital Victoria Largest city Vancouver Official languages English Government - Lieutenant-Governor Iona Campagnolo - Premier Gordon Campbell (BC Liberal) Federal representation in Canadian Parliament - House seats 36 - Senate seats 6 Confederation July 20, 1871 (6th province) Area Ranked 4th - Total 944,735 km... This article deals with the U.S. state. ...

Noise from shipping, drilling, and other human activities can interfere with the acoustic communication and echolocation of Orcas. In the mid-1990s, loud underwater noises from salmon farms were used to deter seals. Orcas subsequently avoided the surrounding waters.^[16] In addition high intensity navy sonar has become a new source of distress for Orcas.^[17] Orcas are popular with whale watchers, which may change Orca behaviour and stress Orcas, particularly if boats approach Orcas too closely or block their line of travel.^[18] Whale watching off the coast of Bar Harbor, Maine. ...

The Exxon Valdez oil spill had an adverse effect on Orcas in Prince William Sound and the Kenai Fjords region of Alaska. One resident pod was caught in the spill; though the pod successfully swam to clear water, eleven members (about half) of the pod disappeared in the following year. The spill had a long-term effect by reducing the amount of available prey, such as salmon, and has thus been responsible for a local population decline. In December 2004, scientists at the North Gulf Oceanic Society said that the AT1 transient population of Orcas (currently considered part of a larger population of 346 transients), now only numbering 7 individuals, has failed to reproduce at all since the spill. This population is expected to become extinct.^[19] This article is about the tank vessel Exxon Valdez. ... Prince William Sound, on the south coast of Alaska. ...

Orcas and humans

Although only scientifically identified as a species in 1758, the Orca has been known to humans since prehistoric times.

The first written description of an Orca is given in Pliny the Elder's Natural History (written circa 70 AD). The aura of invincibility around the all-consuming Orca was well-established by this time. Having observed the public slaughter of an Orca stranded at a harbour near Rome, Pliny writes, "Orcas (the appearance of which no image can express, other than an enormous mass of savage flesh with teeth) are the enemy of [other whales]... they charge and pierce them like warships ramming."^[20] Pliny the Elder: an imaginative 19th Century portrait. ... Nickname: Motto: SPQR: Senatus Populusque Romanus Location of the city of Rome (yellow) within the Province of Rome (red) and region of Lazio (grey) Coordinates: Region Lazio Province Province of Rome Founded 21 April 753 BC Government  - Mayor Walter Veltroni Area  - City 1,285 km²  (580 sq mi)  - Urban 5...

Whaling

An adult male Orca with its characteristic tall dorsal fin swims in the waters near Tysfjord, Norway

Orcas were targeted in commercial whaling for the middle part of the twentieth century once stocks of larger species had been depleted. Commercial hunting of Orcas came to an abrupt halt in 1981 with the introduction of a moratorium on all whaling. (Although from a taxonomic point of view an Orca is a dolphin rather than a whale, it is sufficiently large to come under the purview of the International Whaling Commission.) Download high resolution version (1054x481, 99 KB)This image (C) User:Pcb21, 2002. ... Download high resolution version (1054x481, 99 KB)This image (C) User:Pcb21, 2002. ... The municipality Tysfjord in the county of Nordland, Norway, has 2,283 inhabitants as of January 1, 2002. ... The crew of the oceanographic research vessel Princesse Alice, of Albert Grimaldi (later Prince Albert I of Monaco) pose while flensing a catch. ... International Whaling Commission Logo The International Whaling Commission (IWC) was set up by the International Convention for the Regulation of Whaling (ICRW)[1] on December 2, 1946 to promote and maintain whale fishery stocks. ...

The greatest hunter of Orcas was Norway, which took an average of 56 animals per year from 1938 to 1981. Japan took an average of 43 animals from 1946 to 1981. (War year figures are not available but are likely to be fewer). The Soviet Union took a few animals each year in the Antarctic, with the extraordinary exception of the 1980 season when it took 916.

Today, no country carries out a substantial hunt. A small level of subsistence whaling is carried out by Indonesia and Greenland. As well as being hunted for their meat, Orcas have also been killed because of competition with fishermen. In the 1950s the United States Air Force, at the request of the Government of Iceland, used bombers and riflemen to slaughter Orcas in Icelandic waters because they competed with humans for fish. The operation was considered a great success at the time by fishermen and the Icelandic government. However, many were unconvinced that Orcas were responsible for the drop in fish stocks, blaming overfishing by humans instead. This debate has led to repeated studies of North Atlantic fish stocks, with neither side in the whaling debate giving ground since that time. The United States Air Force (USAF) is the aerial warfare branch of the United States armed forces and one of the seven uniformed services. ... Iceland is a republic. ... The B-17 Flying Fortress is one of the most recognizable and famous bombers of World War II. A bomber is a military aircraft designed to attack ground targets, primarily by dropping bombs. ... A rifle is a firearm with a barrel that has a helical groove or pattern of grooves (rifling) cut into the barrel walls. ...

Orcas have been known to co-operate with humans in the hunting of other whales. One well-known example occurred near the port of Eden in South-Eastern Australia in the 1920s. A pod of Orcas, led by a dominant male called Old Tom, would assist whalers in hunting baleen whales. The Orcas would find the target whales, shepherd them into Twofold Bay and then alert the whalers to their presence and often help to kill the whales. After the harpooning, some of the Orcas would even grab the ropes in their teeth and aid the whalers in hauling. The skeleton of Old Tom is on display at the Eden Killer Whale Museum, and significant wear marks still exist on his teeth from repeatedly grabbing fast moving ropes. In return for their help, the whalers allowed the Orcas to eat the tongue and lips of the whale before hauling it ashore. The Orcas would then also feed on the many fish and birds that would show up to pick at the smaller scraps and runoff from the fishing. Fear of Orcas has dissipated in recent years due to better education about the species, including the appearance of Orcas in aquariums. Eden (postcode 2551. ... Old Tom was the name given to a Killer Whale by whalers in the port of Eden on the South-East coast of Australia. ... Families Balaenidae Balaenopteridae Eschrichtiidae Neobalaenidae Scientifically known as the Mysticeti, the baleen whales, also called whalebone whales or great whales, form a suborder of the order cetacea. ... Twofold Bay is a bay in the South East of Australia. ...

Captivity

See also: List of marine parks with Orcas

The Orca's intelligence, trainability, striking appearance, playfulness in captivity and sheer size have made it a popular exhibit at aquariums and aquatic theme parks. The first Orca capture and display occurred in Vancouver in 1964. Over the next 15 years around 60 or 70 Orcas were taken from Pacific waters for this purpose. The Southern Resident community of the northeast Pacific lost 48 of its members to captivity; by 1976 only 80 Orcas were left in the community, which remains endangered.^[4] In the late 1970s and the first half of the 1980s, Orcas were generally taken from Icelandic waters (50 in the five years to 1985). Since then, Orcas have been successfully bred in captivity and wild specimens are considerably rarer. This is a list of marine theme parks with captive orcas. ... The term Animal intelligence is currently used in three distinct but overlapping ways: as a synonym for animal cognition, to pose the question “are animals intelligent?”, or to denote a discussion of relative levels of intelligence in different animal species. ... Vancouver (pronounced: ) is a city in south-western British Columbia, Canada. ...

The practice of keeping Orcas in captivity is controversial, and organisations such as the World Society for the Protection of Animals and the