The killer whale or orca ( Orcinus orca ) is a tooth whale belonging to a family of ocean dolphins, which is the largest member. Killer whales have diverse diets, although individual populations often specialize in certain types of prey. Some feed exclusively on fish, while others hunt marine mammals such as seals and dolphins. They are known to attack baleen whales, and even adult whales. Killer whales are the top predators, because no animals prey on them. Killer whales are considered cosmopolitan species, and can be found in every ocean in the world in a variety of marine environments, from Arctic and Antarctic to tropical oceans - killer whales only absent from the Baltic Sea and Black Sea, and some Arctic Ocean regions.
Killer whales are very social; some populations consist of matrilineal family groups (pods) which are the most stable animal species. Their sophisticated hunting techniques and vocal behavior, which are often specific to a particular group and passed down from generation to generation, have been described as manifestations of animal culture.
The International Union for Nature Conservation assesses the status of orca conservation as less data because of the possibility that two or more types of killer whales are a separate species. Some local populations are considered threatened or endangered due to destruction of prey, habitat loss, pollution (by PCBs), arrests for marine mammal parks, and conflicts with human fisheries. At the end of 2005, Southern Resident Killer Whales, a population that inhabits British Columbia and waters of Washington state, is placed on the US Endangered Species list.
Wild whales are not considered a threat to humans, but there are cases of captured orcas that kill or hurt their handling in marine amusement parks. Killer whales are particularly prominent in indigenous cultural mythology, with their reputation ranging from the human soul to the merciless murderer.
Video Killer whale
Taxonomy and evolution
Orcinus orca is the only recognized species in the genus Orcinus , one of the many animal species originally described by Linnaeus in 1758 in < i> Systema Naturae . Konrad Gessner wrote the first scientific description of the killer whale in his book Piscium & amp; aquatilium animantium natura in 1558, part of a larger animalium historicia , based on the examination of dead animals stranded in Greifswald Bay that has attracted much local attention.
The killer whale is one of 35 species in the oceanic dolphin family, which first appeared about 11 million years ago. The genealogies of the whales may branch off shortly afterwards. Despite having a morphological similarity to dwarf-killer whales, false killer whales and pilot whales, cytochrome gene sequence research by Richard LeDuc indicates that his closest remaining relative is the snubfin dolphin of the orcaella genus .
Common names
English-speaking scientists most often use the term "killer whale", although the term "orca" is increasingly being used. Killer whale killer shows that it has a long inheritance. Indeed, the genus name Orcinus means "kingdom of the dead", or "belonging to Orcus". The ancient Romans originally applied orca (plural orcae ) to these animals, possibly borrowing it from the Greek ? ??? , which refers (among other things) to whale species. Since the 1960s, "orca" has continued to grow in popularity; both names are now used. The term "orca" is subtly favored by some to avoid the negative connotation of "killer", and because, being part of the Delphinidae family, this species is more closely related to other dolphins than whales.
According to some authors, the name killer whale is a mistranslation of the 18th century Spanish name asesina-ballenas which literally means
They are sometimes referred to as "blackfish", a name that is also used for other whale species. "Grampus" is an old name for the species, but is now rarely used. The meaning of "grampus" is not to be confused with the genus of Grampus , whose only member is the Risso dolphin.
Type
Three to five types of killer whales may be different enough to be considered racial, subspecies, or even different species (see Species issue). The IUCN reported in 2008, "The taxonomy of this genus clearly requires a review, and it is likely that O. Orca will be divided into a number of different species or at least subspecies over the next few years." Although large variations in ecological specificity of different killer whale groups make it difficult for simple differentiation into types, research off the west coast of Canada and the United States in the 1970s and 1980s identifies the following three types:
- Population : This is the most commonly seen of the three populations in coastal waters of the northeast Pacific. The population food consists mainly of fish and sometimes squid, and they live in complex and integrated family groups called pods. The typical female inhabitant has a rounded dorsal fin tip that ends at a sharp angle. They visit the same area consistently. Population residents of British Columbia and Washington are among the most intensive marine mammals studied anywhere in the world. Researchers have identified and named more than 300 killer whales over the past 30 years.
- Transients : This whale diet consists almost entirely of marine mammals. Transients generally travel in small groups, usually two to six animals, and have fewer family ties than residents. Transients are voiced in less variable and less complex dialects. Female transients are characterized by more triangular and pointed dorsal fins compared to residents. The gray or white area around the dorsal fins, known as the "saddle saddle", often contains some black coloring in the dwellers. However, the transient saddle is solid and the uniform is gray. Transients roam along the coast; several people have been seen in southern Alaska and California. Transients are also referred to as Bigg's whaling whales in honor of the cetologist Michael Bigg. This term is becoming increasingly common and can eventually replace a temporary label.
- Offshore : The third population of killer whales in the northeastern Pacific was discovered in 1988, when a humpback whale researchers observed it in open water. As the name implies, they travel far from shore and feed primarily on school fish. However, because they have large dorsal fins, scars and tears are similar to transients of mammal hunting, they may also eat mammals and sharks. They are mostly found off the west coast of Vancouver Island and near Haida Gwaii. Offshores usually gather in groups of 20-75, with occasional group appearances of up to 200. Little is known about their habits, but they are genetically distinct from the population and transients. Offshores appear to be smaller than others, and women are marked with a rounded tip of the dorsal fin.
Transients and residents live in the same area, but avoid each other.
Other populations have not been studied, although special fish and mammals feeding killer whales have been distinguished elsewhere. In addition, separate populations of "generalists" (fish-and mammals-fed) and "specialists" (mammals-fed) killer whales have been identified in northwestern Europe. Like populations and transients, the lifestyles of these popes seem to reflect their diet; fish-eating killer whales in Alaska and Norway have similar population-like structures, while mammal-eating whales in Argentina and the Crozet Islands behave more like transients.
Three types have been documented in Antarctica. Two dwarf species, named Orcinus nanus and Orcinus glacialis , were described during the 1980s by Soviet researchers, but most cetacean researchers are skeptical about their status, and connect this directly to the type explained below is difficult.
- Type A looks like a "regular" killer whale, large, black and white with medium-sized white eyes, living in open water and feeding mostly on minke whales.
- Type B is smaller than type A. It has a large white eye patch. Most of the dark parts of the body are medium gray, not black, despite having dark gray spots called "dorsal cape" that extend back from the forehead to the back of the dorsal fin. The white area was stained with yellow. It feeds mostly on the seal.
- Type C is the smallest type and lives in a larger group than the others. The blindfold is clearly tilted forward, rather than parallel to the body axis. Like type B, it's mainly white and medium gray, with dark gray robe and yellow-colored patches. The only observed monster is the Antarctic cod. Type D was identified based on 1955 photographs of mass stranded in New Zealand and six sightings at sea since 2004. The first videotape of this kind in life occurred between the Kerguelen and Crozet Islands in the year 2014. Immediately recognized by a patch of white eyes that are very small, narrower and shorter than the usual dorsal fin, round head (similar to pilot whales), and smaller teeth. Its geographical range appears to be circular in subantarctic waters between latitudes 40 Â ° S and 60 Â ° S. And although nothing is known about the Type D diet, it is thought to include fish because the group has been photographed around longline vessels, where they reportedly preyed on Patagonia teeth ( Dissostichus eleginoides ).
Types B and C live close to ice packs, and diatoms in these waters may be responsible for coloring the yellowish of both types. Mitochondrial DNA sequences support the theory that this is a separate species recently. Recently, complete mitochondrial sequences show two Antarctic groups feeding seals and fish should be recognized as distinct species, as do North Pacific transients, leaving others as subspecies waiting for additional data. Sophisticated methods that sequence the entire mitochondrial genome reveal systematic differences in DNA among different populations.
Mammal-eatered killer whales are thought to be long associated with mammal-eating killer whales from different regions, but genetic testing disputes this hypothesis.
The seven identified ecotypes inhabit the isolated ecological niche. Of the three orc ecotypes in Antarctica, one preys on minke whales, the second in seals and penguins and the third in fish. Other ecotypes live in the eastern North Atlantic, while the three Northeast Pacific ecotypes are labeled transient, resident and offshore populations, as discussed above. The study supports a proposal to reclassify fish and fish feeder populations in Antarctica and North Pacific transients as distinct species, leaving the remaining ecotype as subspecies. The first split in the orca population, between North Pacific transients and the rest, occurred about 700,000 years ago. Such an assignment would mean that each new species is the subject of separate conservation assessments.
Maps Killer whale
Appearance and morphology
A typical killer whale bear black back, white chest and sides, and white patches above and behind the eyes. The calf is born with a yellowish or orange color, which fades to white. It has a heavy and strong body with large dorsal fin to 1.8 m (5.9 ft). Behind the flipper, it has a dark gray "saddle patch" on the back. Antarctic killer whales may have pale gray hairs on almost white backs. The adult killer whale is very different and usually not confused with other sea creatures. When viewed from a distance, teenagers may be confused with other cetacean species, such as false killer whales or Risso dolphins. The killer whale's teeth are very strong and the jaw hardens; the upper teeth fall into the gap between the lower teeth when the mouth is closed. The front teeth tend to be slightly forward and outward, allowing the killer whales to resist the powerful jerking motion of the prey while the middle and back teeth hold it firmly in place.
Killer whales are the largest remaining dolphins. Males usually range from 6 to 8 meters (20 to 26 feet) and weigh more than 6 tons (5.9 tons long, 6.6 tons short). Females are smaller, generally ranging from 5 to 7 m (16 to 23 feet) and weighing about 3 to 4 tonnes (3.0 to 3.9 ton long, 3.3 to 4.4 ton short). The largest recorded killer whale is 9.8 m (32 ft), weighing 10 tonnes (9.8 ton long, 11 ton short), while the largest female is 8.5 m (28 ft), weighing 7, 5 tons (7.4 tons long; 8.3 tons short). Calves at birth weigh about 180 kg (400 pounds) and about 2.4 m (7.9 feet). The large size and strength of the killer whales make it one of the fastest marine mammals, capable of reaching speeds of more than 56 km/h (30 kn). The killer whale's skeleton is a typical, but stronger, delphinid structure. Its integument, unlike most other dolphin species, is characterized by a well-developed dermal layer with a dense network of collagen fibers.
The pectoral fin fin fin, analogous to the forelimbs, is large and rounded, resembling an oar. Males have a significantly larger pectoral fins than women. Approximately 1.8 m (5.9 ft) of male dorsal fins is more than twice the size of a female and more triangular - a triangle of long, elongated legs - while shorter and more curved. Men and women also have different black and white skin patterns in their genital area. Sexual dimorphism is also seen in the skull; adult males have lower jaws than women, and have larger occipital peaks.
An individual killer whale can often be identified from the dorsal fin and the saddle saddle. Variations such as nicks, scratches, and tears on the dorsal fin and white or gray patterns in the saddle patch are unique. The published directory contains photos and names identified for hundreds of North Pacific animals. Photographic identification has enabled local populations of killer whales to be counted annually than estimated, and has enabled great insight into the life cycle and social structure.
Sometimes killer whales are white; they have been found in the northern Bering Sea and around St. Lawrence, and near the Russian coast. In February 2008, a white-killing whale photographed 3.2 km (2.0 million) from Kanaga Volcano in the Aleutian Islands. In 2010, the Far Eastern Russia Orca Project (FEROP), co-founded and directed by Alexander M. Burdin and Erich Hoyt, filmed a grown man dubbed Iceberg.
Killer whales have good eyesight above and below water, excellent hearing, and a good touch. They have very sophisticated ecolocation capabilities, detect the location and characteristics of prey and other objects in their environment by emitting clicks and listening to echoes, as do other members of the dolphin family. The average body temperature of orca is 36 to 38 ° C (97 to 100 ° F). Like most marine mammals, orcas have a layer of insulating blubber ranging from 7.6 to 10 cm (3.0 to 3.9 inches) thick under the skin. The heart beats at a rate of about 60 times/minute when the orca is on the surface, dropping to 30 beats/min when submerged.
Life cycle
Female killer whales begin to mature at about 10 years (reaching a peak of about 20), consisting of a polyestrous cycling period with a non-biking period of between three and 16 months. Women can often breed until age 40, after which there is a rapid decline in fertility. Thus, orcas are animals that experience menopause and live for decades after they have finished breeding. The life span of wild females averages 50 years. Some claimed to have lived much longer; Grandmother (J2) was estimated by some researchers to be 105 years old at the time of her death, but the biopsy sample showed her age was 65-80.
To avoid inbreeding, males mate with females from other pods. Gestation varies from 15 to 18 months. The mother gives birth, usually one offspring, about once every five years. In population pods, births occur at any time of the year, although winter is the most common. Death is very high during the first seven months of life, when 37-50% of all calves die. Weaning starts about 12 months and finishes at the age of two. According to observations in some areas, all male and female pod members participate in the care of young people.
Male adults are sexual at age 15, but usually do not reproduce until age 21. Wild men live on average about 29 years, with a maximum of about 60 years. A man, known as Old Tom, is reportedly seen every winter between the 1840s and 1930s in New South Wales, Australia. This will make it to 90 years. Her teeth examination showed she died around the age of 35, but this age-setting method is now believed to be inaccurate for older animals. A man known to researchers in the Pacific Northwest (identified as J1) is estimated to be 59 years old when he died in 2010. Killer whales are unique among cetaceans, as their heads become relatively shorter as they age, ie, orca's caudal more-very relative to his head.
Infanticide, once regarded only in captive killer whales, was found to be present in a wild population after being documented by researchers from British Columbia for the first time in 2018. In this incident, an adult male kills a woman's calf in a pod. Adult males also joined in the attack. The exact reason for the infant's killing is unknown, but theorizes that men kill young calves to mate with their mothers (something that happens to other carnivorous species), while the male attacker's mother may have joined in to provide breeding. opportunity for his son. These findings suggest that killer whales are willing to infanticide, as do many smaller species of dolphins such as bottlenose dolphins known to perform.
Range and habitat
Killer whales are found in all oceans and most oceans. Because of their enormous range, amount and density, distribution estimates are difficult to compare, but they obviously prefer higher latitudes and coastal areas than pelagic environments. Areas that serve as major study sites for species including the coast of Iceland, Norway, Argentina's Valdes Peninsula, the Crozet Islands, New Zealand and parts of the west coast of North America, from California to Alaska.
Systematic surveys show the highest density of killer whales (0.40 individuals per 100Ã, kmÃ,²) in the northeast Atlantic around the coast of Norway, in the northern Pacific along the Aleutian Islands, Alaska Gulf and in the Southern Ocean on most beaches Antarctica. They are considered "common" (0.20-0.40 individuals per 100Ã, kmÃ,²) in the eastern Pacific along the coasts of British Columbia, Washington and Oregon, in the North Atlantic Ocean around Iceland and the Faroe Islands. High density has also been reported but not calculated in the western North Pacific around the Sea of ​​Japan, the Okhotsk Sea, Kuril Islands, Kamchatka and Islands Commanders and in the Southern Hemisphere just off southern Brazil and the southern tip of Africa. They are reported as common seasonality in the Canadian Arctic, including Baffin Bay between Greenland and Nunavut, as well as Tasmania and Macquarie Island and populations that occur regularly or differently in Northwest Europe, California, Patagonia, Crozet Islands, Marion Island, South Australia. and New Zealand. The northwest Atlantic population of at least 67 individuals ranges from Labrador and Newfoundland to New England with sightings to Cape Cod and Long Island.
Information for offshore areas and warmer waters is rarer, but widespread sightings suggest killer whales can survive at most water temperatures. They have been seen, though more rarely, in the Mediterranean, the Arabian Sea, the Gulf of Mexico, and the Caribbean. More than 50 individual whales have been documented in the northern Indian Ocean, including two individuals seen in the Persian Gulf in 2008 and off the coast of Sri Lanka by 2015. The orcas occasionally enters the Red Sea through the Gulf of Aden. The modern status of species along mainland China and beyond is unknown. Recorded sightings have been made from almost all coastlines. The vast population is likely to be in the central Pacific, with multiple sightings off the coast of Hawaii. Different populations may also exist off the west coast of tropical Africa, and Papua New Guinea. In the Mediterranean, killer whales are considered "visitors", possibly from the North Atlantic, and sightings are becoming less common in the east. However, a small population throughout the year is known to exist in the Strait of Gibraltar. Killer whales also appear regularly on the Galapagos Islands.
In Antarctica, the killer whales are on the edge of the ice and are believed to be entering solid ice, finding open tin like a beluga whale in the Arctic. However, the killer whales are only seasonal visitors in the Arctic waters, and not close to ice packs in the summer. With the decline of Arctic sea ice in the Hudson Strait, their range now extends far into the northwest Atlantic. Occasionally, killer whales swim into freshwater rivers. They have been documented 100 miles (160 km) on the Columbia River in the United States. They are also found in the Fraser River in Canada and the Horikawa River in Japan.
Migration patterns are not well understood. Every summer, the same people appear on the shores of British Columbia and Washington. Despite decades of research, where these animals go for the rest of the year is still unknown. Transient pods have been sighted from southern Alaska to central California.
Population
Estimates of populations around the world are uncertain, but recent consensus shows an absolute minimum of 50,000. Local estimates include about 25,000 in Antarctica, 8,500 in the tropical Pacific, 2,250-2,700 from the cooler northeast Pacific and 500-1,500 from Norway. Japan's Fisheries Agency estimates 2,321 killer whales are in the oceans around Japan.
Giving Feeding
Killer whales are the top predators, meaning that they themselves have no natural predators. They are sometimes called the sea wolves, because they hunt in groups like wolves. Killer whales hunt for varied prey including fish, squid, mammals, sea birds, and turtles. Different populations or ecotypes can specialize and some can have a dramatic impact on certain prey species. However, whales inhabiting the tropics seem to have a more general diet due to lower food productivity.
Fish
Predator eater predates about 30 species of fish. Some populations in the Norwegian and Greenland seas specialize in herrings and follow the autumn migration of fish to the coast of Norway. Salmon is responsible for 96% of the diet of the northeastern Pacific population. About 65% of them are big Chinook, fat. Chum salmon is also edible, but smaller sockeye and pink salmon are not significant foods. The depletion of certain prey species in an area, therefore, raises concern for the local population, despite the high diversity of prey. On average, a killer whale takes 227 kilograms (500 pounds) every day. While salmon is usually hunted by individuals or a small group of individuals, herring is often caught using a carousel meal; Killer whales force herring into tight balls by releasing bubble bursts or flashing their white bottom. They then slap the ball with their tail worms, either surprisingly or kill up to 15 fish at once. The herring is then eaten one by one. Carusel administration is only documented in the Norwegian population of killer whales and with some species of sea dolphins.
In New Zealand, sharks and rays appear to be important prey; Species taken include eagle rays, long tail and short stingrays, general thrillers, hammerhead sharks, blue sharks, basking sharks and shortfin mako sharks. With sharks, orcas can lead them to the surface and attack them with their tailworms, while the lower rays are cornered, pinned to the ground and brought to the surface. In other parts of the world, species that have been prey include large sharks, tiger sharks and even small whale sharks. Killer whales have also been recorded feeding on large white sharks including one incident that was filmed near the Farallon Islands in October 1997, where 4.7-5.3 meters (15-17 feet) of orca women killed 3-4 meters (9.8 -13.1 ft) white shark, possibly causing a tonic immobility before breastfeeding. A group of orcas has been recorded killing white sharks off South Australia. and has been blamed for deaths in South Africa. They seem to target the heart of this species. Competition between killer whales and white sharks may occur in areas where food preferences overlap.
Mammals
Killer whales are highly sophisticated and effective marine mammal predators. Thirty-two species of cetaceans have been recorded as prey, from observing orcas feeding, examining the dead orcas, and seeing scars on the bodies of living prey animals. Groups even attack larger cetaceans such as minke whales, gray whales, and, rarely, sperm whales or blue whales.
Big whale hunting usually takes a few hours. Killer whales generally choose to attack young or weak animals; However, a group of five or more can attack healthy adults. When hunting a young whale, a group chases and its mother until they are worn out. Finally, they separate the couple and surround the calf, preventing it from surfacing to breathe, drowning it. Female sperm whales sometimes protect themselves by forming a protective circle around their calves with their worms facing outward, using them to repel the attackers. Rarely, large killer whales can overwhelm adult female sperm whales. Adult male sperm whales, large, strong and aggressive when threatened, and adult blue adult whales, which may be too big to be flooded, are not believed to be prey for killer whales.
Prior to the emergence of whaling, large whales may be the main source of food for killer whales. The introduction of modern whaling techniques may have helped killer whales with exploding lance sounds indicating the availability of prey to scavenge, and compressed air inflation from whale carcasses that cause them to float, thus exposing them to scavenging. However, large whale populations by unlimited whaling may have reduced their availability as a prey for killer whales, and caused them to expand the consumption of smaller marine mammals, thus contributing to their decline as well.
Predation by orcas in young whales in high productivity, high latitudes has been hypothesized to be the reason for the migration of large whales into low-productivity tropical water, to reduce the risk of attack on the highly susceptible calves due to the lower density of orcas in these waters..
Other marine mammal species include nearly 20 species of seals, sea lions and seals. Walrus and sea otters are seldom taken. Often, to avoid injury, the killer whale disables its prey before killing and eating it. This may involve throwing it in the air, slapping it with their tail, bumping it, or breaking and landing on it. Sea lions were killed by heads sank or after a stunning blow from a tail accident. In the Aleutian Islands, the decline in sea otter populations in the 1990s was controversially linked by some scientists to predation of whale killers, albeit without direct evidence. The degeneration of sea otters is followed by the decline of seal ports and the population of Steller's sea lions, a prey favored by killer whales, which in turn may be a substitute for their original prey, which is now destroyed by industrial fishing.
In its steep sands off the peninsula of ValdÃÆ' Â © s, Argentina, and the Crozet Islands, killer whales feed on South American sea lions and southern elephants in shallow waters, even beaches temporarily take their prey before stretching back into the sea. Beaching, usually fatal to cetaceans, is not an instinctive behavior, and can take years of practice for young people. Killer whales can then release animals near adolescent whales, allowing younger whales to practice difficult fishing techniques on currently weak prey. The "spider hunter" of spy whales to find the Weddell seal, the crabeater, the leopard seal, and the penguins rely on ice clumps, then swim in groups to create waves that wash away the lumps. It washes the prey into the water, where other killer whales wait.
Killer whales have also been observed feeding on terrestrial mammals, such as deer swimming among islands off the northwest coast of North America. Killer whale cannibalism has also been reported based on abdominal contents analysis, but this may be the result of the remains of scavengers being dumped by whalers. One killer whale was also attacked by his friends after being shot. Although predatory killer whales have never been observed to eat other marine mammals, they occasionally harass and kill dolphins and seals for no apparent reason.
Bird
Killer whales in many areas may prey on birds and seagulls. A killer whale in MarineLand finds the fish can spew fish to the surface, attract sea gulls, and then eat birds. Four others later learned to imitate the behavior.
Behavior
Daily killer whale behavior generally consists of foraging, traveling, resting and socializing. Killer whales engage in frequent behavior on the surface such as breaking (jumping completely out of the water) and slapping the tail. These activities may have various purposes, such as courtship, communication, getting rid of parasites, or playing. Spyhopping, the behavior in which the whale holds his head above the water, helps the animal look around.
Resident killer whales swim with dolphins, other dolphins, seals, and sea lions, which are common prey for transient killer whales.
Social structure
Killer whales are famous for their complex society. Only elephants and higher primates, like humans, live in very complex social structures. Due to the complex social and societal ties of orcas, many oceanographers have concerns about how humanly keeping these animals in captivity.
The killer whale in the eastern North Pacific has a very complex and stable social grouping system. Unlike other mammalian species whose social structure is known, people live with their mothers for the rest of their lives. These family groups are based on a matriarch consisting of the oldest woman (matriarch) and her sons and daughters, and the offspring of her daughters, etc. The average size of matriline is 5.5 animals. Because women can reach the age of 90, as many as four generations travel together. These matrilineal groups are very stable. Individuals are separated for only a few hours each time, for mating or foraging. With one exception, a killer whale named Luna, no permanent separation from an individual from a citizen matriline has been recorded.
The closely related matrilin forms a loose aggregation called a pod, usually consisting of one to four matrilines. Unlike matrilines, pods can be separated for weeks or months at a time. DNA tests show that male population almost always mates with women from other pods. The clan, the next level of the social structure of the population, consists of pods with the same dialect, and the legacy of older but older ancestors. Clan ranges overlap, mixing pods from different clans. The last association layer, perhaps more arbitrarily defined than the family clustering, is called the community, and is defined as a cluster of clans that are regularly mixed. Clans in the community do not share vocal patterns.
Transient pods are smaller than pods, usually consisting of adult women and one or two offspring. Men usually maintain stronger relationships with their mothers than other women. These bonds can be extended to adulthood. Unlike residents, long or permanent separations from temporary offspring of common birth matrilines, with adolescents and adults of both sexes participating. Some men become "inventors" and do not form long-term associations, sometimes joining groups containing reproductive women. As in the residents clan, members of the community while sharing an acoustic repertoire, although regional differences in vocalizations have been recorded.
Vocalizations
Like all cetaceans, killer whales depend heavily on underwater sounds for orientation, feeding, and communication. They produce three categories of sound: clicks, whistles, and pulsed calls. Clicks are believed to be used primarily for navigation and differentiate prey and other objects in the surrounding environment, but also often heard during social interaction.
The Pacific Northeast population tends to be much more vocal than the temporary group in the same waters. Residents feed mainly on Chinook and chum salmon, a species that is insensitive to killer whale calls (inferred from gram of Atlantic salmon salt). In contrast, the prey sea mammals of transients hear well underwater at the frequencies used in killer whale calls. Thus, transients are usually silent, perhaps to avoid alerting their prey mammals. They sometimes use one click (called faint clicks) rather than the long train clicks observed in other populations. Residents are silent only when resting.
All members of the population pod use a similar vocation, known collectively as dialect. The dialect consists of a certain number and type of discrete, repeated calls. They are complex and stable over time. Typical patterns and call structures in matrilines. Newborns produce calls that are similar to their mothers, but have a more limited repertoire. Individuals tend to study their dialect through contact with their mother and other pod members. For example, certain family calls have been observed more frequently in the days following the birth of calves, which can help calves learn about them. Dialects may be an important means of maintaining group identity and cohesiveness. The similarities in dialect may reflect the degree of interconnection between pods, with building variations over time. When the pod converges, the dominant call type decreases and the subset call type increases. The use of both types of calls is called biponasi. Increased subset call types can be a distinguishing factor between pods and inter-pod contacts.
The killer whale's dialect not only distinguishes them among pods, but also between species. The resident dialect contains seven to 17 (mean = 11) special call types. All members of the west coastal transient community of North America express the same basic dialect, although small regional variations in this type of call are clear. Preliminary research has shown that offshore killer whales have specific group dialects that are different from residents and transients.
The vocalizations of killer whales in other parts of the world have also been studied. Norway and Iceland eating orcas fish seem to have different vocalizations for activities such as hunting and traveling.
Intelligence
Killer whales have the second heaviest brain among marine mammals (after sperm whales, which have the largest brains of any animal). They can be trained in captivity and are often described as smart, although defining and measuring "intelligence" is difficult in species whose environments and behavior strategies are very different from humans.
Killer whales imitate others, and seem to deliberately teach skills to their brothers. Outside the Crozet Islands, mothers push their calves to shore, waiting to recall the child if necessary.
People who interact closely with killer whales offer many anecdotes that show the curiosity, pleasure, and whale's ability to solve problems. Alaska's killer whales not only learn how to steal fish from longlines, but also overcome various techniques designed to stop them, such as the use of unwarranted lines as bait. Once, fishermen place their boats several miles apart, taking turns taking their catches in small quantities, in the hope that the whales will not have enough time to move between the boats to steal the catch when the fish is taken. One researcher explained what happened next:
This works very well for a while. Then the pope is divided into two groups. In fact they do not take an hour to find out. They were so happy when they knew what was happening, that we were playing games. They broke by boat.
In other anecdotes, the researchers describe an incident in which wildly killer whales play teasingly humans by repeatedly removing objects that human beings are trying to reach, or suddenly start throwing a piece of ice after a man throws a snowball.
The use of the killer whale dialect and the passage of behavior learned from generation to generation has been described as a form of animal culture.
The vocal culture and the complex and stable behavior of the sympatric groups of orcinus orca (orcinus orca) seem to have no parallels outside of humans and represent an independent evolution of the faculty of culture.
(Two species or populations are considered sympatric when they exist in the same geographical area and thus regularly meet each other.)
Preservation
In 2008, the IUCN (International Union for Conservation of Nature) changed the assessment of the conservation status of killer whales from conservation that rely on less data, recognizing that one or more types of killer whales may be completely separate, endangered species. The depletion of species of prey, pollution, large-scale oil spills, and habitat disturbance caused by noise and conflicts with ships are the most significant world threats.
Like other animals at the highest trophic level, killer whales are especially at risk of poisoning from toxic bioaccumulation, including polychlorinated biphenyls (PCBs). The European port seals have problems in reproductive and immune function associated with high levels of PCB and related contaminants, and offshore surveys of Washington found PCB levels in killer whales higher than levels that have caused health problems at seaports. Blubber samples in the Norwegian Arctic showed higher levels of PCBs, pesticides and brominated retardants than in polar bears. When food is scarce, killer whales metabolize fats for energy, which increases the concentration of pollutants in their blood.
In the Northwest Pacific, the stock of wild salmon, the main food source of the population, has dropped dramatically in recent years. On the west coast of Alaska and the Aleutian Islands, seabed populations and sea lions have also decreased substantially.
In 2005, the United States government registered a southern population community as an endangered population under the Endangered Species Act. This community consists of three pods that mostly live in Georgia and Haro Straits and Puget Sound in British Columbia and Washington. They do not breed outside of their community, which was once thought to be around 200 animals and then shrink to about 90. In October 2008, an annual survey revealed seven missing and allegedly dead, reducing the count to 83. This has the greatest potential population decline in the last ten years. This death can be attributed to the decline of Chinook salmon.
Scientist Ken Balcomb has extensively studied killer whales since 1976; he is a research biologist who is responsible for finding a US Navy sonar that can harm killer whales. He studied the killer whale from the Whale Research Center, located in Friday Harbor, Washington. He was also able to study the killer whales from his "porch home perched on top of Puget Sound, where animals hunt and play in the summer". In May 2003, Balcomb (along with other whale observers near the coast of Puget Sound) saw the unusual behavior displayed by killer whales. The pope looks "restless and moves in vain, trying to raise their heads free of water" to avoid sonar sound. "Balcomb confirmed at the time that ping ping sounds detected underwater with an underwater microphone were sonar.The sound was from a US Navy frigate 12 miles (19 kilometers) away, Balcomb said. The impact of sonar waves on killer whales is potentially life-threatening. Three years before the discovery of Balcomb, research in the Bahamas showed 14 beak whales stranded on shore. These whales were stranded on the day the US Navy destroyer was turned into sonar training. Of the 14 whales that were stranded on the beach, six of them died. The six dead whales were studied, and a CAT scan of two whale heads showed bleeding around the brain and ear, which is consistent with the decompression disease.
Other conservation concerns were announced in September 2008 when the Canadian government decided that there was no need to enforce further protection (including the Species at Risk Act in place to protect endangered animals throughout its habitat) for killer whales other than existing laws. In response to this decision, six environmental groups sued the federal government, claiming the killer whales face many threats on the British Columbia Coast and the federal government has done nothing to protect them from this threat. The legal and scientific nonprofit organization Ecojustice leads the lawsuit and represents the David Suzuki Foundation, the Environmental Defense, Greenpeace Canada, the International Fund for Animal Welfare, the Raincoast Conservation Foundation, and the Wilderness Committee. Many scientists involved in the lawsuit, including Bill Wareham, a marine scientist with the David Suzuki Foundation, noted an increase in boat traffic, toxic wastewater, and low salmon populations as a major threat, putting about 87 killer whales on the coast of British Columbia at risk.
Underwater noise from shipping, drilling, and other human activities is a significant concern in some of the major killer whale habitats, including the Johnstone Strait and the Haro Strait. In the mid-1990s, loud underwater sounds from salmon farms were used to block the seals. Killer whales also avoid the surrounding water. The high intensity sonar used by the Navy disturbs killer whales along with other marine mammals. Killer whales are very popular among pope watchers, who can emphasize whales and change their behavior, especially if the ship is approaching too close or blocking their path.
The Exxon Valdez oil spill had a devastating impact on the killer whales in Prince William Sound and Kenai Fjords region in Alaska. Eleven members (about half) of one pod of residents disappeared the following year. Damaged salmon spills and other prey populations, which in turn damage local killer whales. In 2009, scientists estimated the transient population of AT1 (considered part of a population greater than 346 transients), only seven people and not reproduced since the spill. This population is expected to die.
Relationships with humans
Indigenous cultures
Indigenous peoples on the Pacific Northwest Coast present killer whales throughout their art, history, spirituality, and religion. Haida regards the killer whales as the most powerful animal in the ocean, and their mythology tells of the killer whales that live in homes and cities under the sea. According to these myths, they take human form when submerged, and drowned humans go to live with them. For Kwakwaka'wakw, killer whales are considered the rulers of the underwater world, with sea lions for slaves and dolphins for warriors. In the mythology of Nuu-chah-nulth and Kwakwaka'wakw, killer whales can manifest the souls of the deceased leaders. The Tlingit of southeastern Alaska regards killer whales as sea guards and human benefactors.
Maritime Archaeologists in Newfoundland also greatly honor killer whales, as evidenced by the stone carvings found in a 4,000-year-old cemetery at the Port au Choix Archaeological Site.
In the stories and beliefs of the Siberian Yupik people, killer whales are said to emerge as wolves in the winter, and wolves as killer whales in summer. Killer whales are believed to assist their hunters in riding walruses. Respect is expressed in several forms: the boat represents animals, and wooden carvings hanging from the hunter's belt. Small sacrifices such as tobacco strewn into the sea for them. Killer whales are believed to have helped the hunters even while hiding wolves, by forcing deer to allow themselves to be killed.
Ainu's native tribe often identified the killer whales in folklore and their myth as Repuy Kamuy (Sea/Offshore God) to bring luck (whale) to the beach, and there was a traditional burial for orcas stranded or already died similar to a funeral for other animals like chocolate bears.
"Killer" stereotype
In Western culture, killer whales have historically been feared as dangerous wild predators. The first written description of a killer whale was given by Pliny the Elder sometime around AD 70, which writes, "Orcas (an apparition that can not be expressed by images, other than the mass of flesh with a very large tooth" Is the enemy of [other whales ]... they attack and stab them like a battleship. "
Of the few confirmed attacks on humans by wild killer whales, nothing is fatal. In one instance, the killer whale tries to pat a clump of ice where a team and a dog photographer from the Terra Nova Expedition stood up. The sling dog bark speculates has sounded quite like a call seal to trigger a killer whale killer curiosity. In the 1970s, a surfer in California was bitten, and in 2005, a boy in Alaska who was plunging in an area frequented by seal harbors was hit by a killer whale that seemed to mistake him for prey. Unlike wild-killer whales, captive killer whales have reportedly made nearly two dozen attacks on humans since the 1970s, some of which have been fatal.
Competition with fishermen also causes killer whales to be considered pests. In the waters of the Pacific Northwest and Iceland, the shooting of the killer whales was accepted and even encouraged by the government. As an indication of the intensity of shooting that occurred until recently, about 25% of killer whales captured in Puget Sound for the aquarium until 1970 have bullet scars. The US Navy claims to have deliberately killed hundreds of killer whales in Icelandic waters in 1956 with machine guns, rockets, and depth charges.
Modern Western Attitude
The Western attitude toward the killer whales has changed dramatically in the last few decades. In the mid-1960s and early 1970s, killer whales came to much greater public and scientific awareness, starting with the first live-capture and featuring a killer whale known as the Moby Doll, a resident struck Saturna Island in 1964. So little was known at the time, almost two months before the whalers found what (fish) food to eat. To their surprise, Moby Doll is a benign and non-aggressive whale that does not try to attack humans.
Between 1964 and 1976, 50 killer whales from the Pacific Northwest were caught for display in an aquarium, and public interest in animals grew. In the 1970s, a study pioneered by Michael Bigg led to the discovery of the complex social structure of the species, the use of vocal communication, and its remarkably stable mother-parent bond. Through photo identification techniques, individuals are named and traced for decades.
The Bigg technique also reveals the Pacific Northwest population is in the lower hundreds than the thousands previously assumed. The southern resident community alone has lost 48 of its members to captivity; in 1976, only 80 were left. In the Northwest Pacific, the mindless species have been subjected to cultural icons in decades.
The increasing public appreciation also led to increased rejection of whale maintenance in aquariums. Only one whale has been taken in the waters of North America since 1976. In recent years, the level of public interest against killer whales has manifested itself in several high-profile efforts around individuals. Following the success of the 1993 film Free Willy, the star catcher Keiko was returned to his Icelandic coast in 1998. The Director of the International Ocean Mammal Project for Earth Island Institute, David Phillips, leads efforts to bring Keiko back to the waters of Iceland. In 2002, the orphan Springer was found in Puget Sound, Washington. He became the first successful whale to be reintegrated into the wild after human intervention, crystallizing decades of research into the vocal behavior and social structure of the region's killer whales. Springer's saving raises the hope that another young killer whale named Luna, who has been separated from his pod, can be returned there. However, his case was marked by controversy over whether and how to intervene, and in 2006, Luna was killed by a ship's propeller.
Whaling
That is earlier than a known record of the commercial hunt for the murderous whales dated to the 18th century in Japan. During the early 19th and early 20th century, the global whaling industry captures many baleen and sperm whales, but most killer whales are ignored because of the limited amount of oil that can be recovered, their smaller population, and the difficulty of taking it. After stocks of larger species ran out, killer whales were targeted by commercial whalers in the mid-20th century. Between 1954 and 1997, Japan took 1,178 killer whales (although the Ministry of the Environment claimed that there were about 1,600 domestic whales between the late 1940s and 1960s) and Norway took 987. More than 3,000 killer whales were taken by Soviet whalers, including catches Antarctica 916 in 1979-80 alone, prompted the International Whaling Commission to recommend a ban on commercial hunting of species awaiting further research. (Compare to the situation on the ground, commercial hunting.) Today, no country has a major hunt, although Indonesia and Greenland allow small hunting (see Aboriginal whaling). In addition to commercial hunting, killer whales are hunted along the coast of Japan due to public concern over potential conflicts with fisheries. Such cases include the semi-resident male and female couples in the Akashi Strait and Harimanada who were killed in the Seto Inland Sea in 1957, the killing of five popes from a pod containing 11 members who swam to Tokyo Bay in 1970, arrests in southern Taiwan in the 1990s.
Working with humans
Killer whales have helped humans hunt other whales. One notable example is the killer whale of Eden, Australia, including the man known as Old Tom. Fishers more often think of them as a nuisance, because orcas will gather to scavenge meat from whalers' catch. Some populations, such as in Prince William Sound in Alaska, may have been significantly reduced by whalers who shot them in retaliation.
Captivity
The intelligence of killer whales, ability to train, striking looks, playfulness in captivity and large size has made it a popular exhibit in aquariums and aquatic amusement parks. From 1976 to 1997, 55 whales were taken from the wild in Iceland, 19 from Japan, and three from Argentina. These numbers exclude animals that died during capture. Direct catches dropped dramatically in the 1990s, and by 1999, about 40% of the 48 animals on display in the world were born from captives.
Organizations such as the World Animal Protection and the Pope and Dolphin Conservation Society campaign against the practice of keeping them in captivity. In captivity, they often develop pathology, such as collapse of the dorsal fin seen in 60-90% of captive men. Prisoners have greatly reduced life expectancy, on average live only in their 20s. In the wild, females survive for 46 years on average, and up to 70-80 years in rare cases. Wild men who survive babies live 31 years on average, and up to 50-60 years old. Captive breeding usually has little resemblance to wild habitats, and whale groups are foreign to those found in the wild. Critics claim that the life of the prisoner is full of pressure because of these factors and the requirement to perform a circus trick that is not part of the behavior of wild killer whales, see above. Wild whale killers can travel up to 160 kilometers (100 miles) a day, and critics say the animals are too big and smart to fit for captivity. Prisoners sometimes act aggressively against themselves, their tank friends, or humans, which critics say are the result of stress. Between 1991 and 2010, the orca bull known as Tilikum was involved in the deaths of three people, and is featured in a critical 2013 movie, Blackfish . Tilikum lived in SeaWorld from 1992 until his death in 2017.
A study 2015 co-authored by staff at SeaWorld and the Minnesota Zoo indicates that there is no significant difference in survival capability between free and captive whales. The authors speculate about future utilities studying the breeding population for the purpose of understanding orca biology and the implications of captive animal studies in overall health of both wild and marine park populations.
Source of the article : Wikipedia
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