Information about killer whales

The killer whale (scientific name: Orcinus orca) is a large toothed whale, 8-10 meters in length, weighing about 9 tons, with a slightly rounded head and an inconspicuous rostrum; the dorsal fin is high and erect, curving up to 1 meter; the body is black and white. The two pterygoid bones are far apart. Temporal fossa large. Mandibles relatively short. 10-12 conical teeth per tooth row in upper and lower jaws. Slender mouth, sharp teeth, ferocious temperament, carnivore, good at attacking prey, is the natural enemy of penguins, seals and other animals. Sometimes they also attack other cetaceans, and even great white sharks, which can be called the king of the sea.

The killer whale is a highly socialized animal, there are some groups composed of the family is the most stable family in the animal kingdom. Some of the orca's complex social behaviors, hunting techniques, and vocal communication are considered evidence that orcas have a culture of their own. Distributed in almost all regions of the oceans, from the equator to polar waters. Water temperature or depth does not limit their range. Distribution extends to many enclosed or semi-enclosed seas, such as the Gulf of Alaska, the Mediterranean Sea, the Sea of Okhotsk, the Gulf of California, the Gulf of Mexico, the Red Sea, and the Persian Gulf.

Morphological features

The maximum recorded length of an adult male killer whale is 9.75 meters, and its weight is 9,524 kilograms. It is the largest of the dolphin family. There is a distinct sexual dimorphism in body size, flipper size and dorsal fin height. Females reach a maximum length of 7.70 meters and males reach 9 meters. Adult males have erect dorsal fins up to 1.0-1.8 m high, while females have distinctly sickle-shaped dorsal fins less than 0.7 m high. The head is slightly rounded with an inconspicuous rostrum. The elliptical fin limbs are located in the first 1/4 of the body length. In males, the limb length can reach 20% of the total body length, in females 11-13%. The caudal lobe can be more than 1/5 the length of the body; the dorsal surface of the body is black with a light gray saddle spot behind the dorsal fin. The mandibles and the ventral surface of the body from the anterior end of the mandibles to the urogenital region are white. There is 1 white foliate spot extending upward from the urogenital region to the side of the body behind the dorsal fin. The ventral surface of the caudal lobe is white or light gray, possibly with a black margin. There is 1 white oval spot above the back of each eye on each side. The saddle spots are inconspicuous when young and become more prominent after sexual maturity.

The condylar base of the adult skull may be up to 1000 mm long. Anterior to the preorbital recess over both premaxillae is less than the width of the anastomosis. The two pterygoid bones are distally segregated. The temporal fossa is large. Mandible relatively short. There are 10-12 teeth on each side of the maxilla and mandible, which are elliptical in cross-section, with the cusps directed inward and backward. In some older individuals, the teeth are often damaged by abrasion or ulceration.

Killer whales are large, fusiform, with a smooth surface and a thick layer of blubber under the skin used to conserve body heat. The body length is about 600-1000 centimeters and the weight is 5,000-10,000 kilograms. The color of the body is black and white, the back is pitch black, just behind the fins there is a saddle-shaped grayish-white spot, behind each eye there is a pike-shaped white spot, most of the ventral surface for the snow-white color. The head is more rounded, without a protruding muzzle, and the nostrils are on the right side of the head, with open and closed flaps, which, when floating to the surface, are opened for breathing, and emit a frothy aerosol, which meets with the cold air of the sea and becomes a column of water. The forelimbs become a pair of fins, which are well developed, and the hind limbs degenerate and disappear. The powerful triangular dorsal fin that towers over the center of the back is very conspicuous, and the male's can be up to 1.5 meters high, serving as both an offensive weapon and a rudder. The mouth is large, with 40-50 large conical teeth on the upper and lower jaws***, capable of swallowing a sea lion whole.

Habitat

The habitat of killer whales is polar and temperate seas mainly. Widely distributed in the waters of the world Japan North Sea, Iceland, for water temperature, depth and other factors do not seem to have obvious limitations. They have a fairly high density of habitat at high latitudes, especially in waters where prey is plentiful. Their movements are commonly associated with tracking prey or increasing predation rates, usually during the fish spawning season and seal production. In the summer, most killer whales in the Atlantic inhabit ice floes or ice-floated waterways, feeding on baleen whales, penguins, seals, and others. Where they migrate to and how far they move remains uncertain. Some orcas remain in Antarctic waters year-round, while those in the Arctic rarely approach ice floes. According to orca researchers in Washington State and British Columbia, there are both sedentary and transient killer whale populations, which can be found throughout the year. Some of these individuals have very large ranges, and photographic identification has shown that some orcas range from Alaska to southern California.

Habits

Swimming

Killer whales are often seen leaping over waves, peering into the water, or slapping the surface of the water with their tail or pectoral fins. In the shallow waters of the bay, it also likes to use the notch in its tail to hook and pull seaweed, making a "whirring" sound that soon covers its body in translucent seaweed. Killer whales can swim as fast as 55 kilometers per hour and can hold their breath for about 17 minutes. When the air around them is cool, they can usually be seen in low, dendritic spouts. Killer whales have an angled, thick and short water column, unlike baleen whales, which are thin and tall. They react to ships in a variety of ways, with indifferent neglect or curiosity possible. Occasionally stranded en masse, groups are sometimes trapped in tide pools or bays. In Arctic and Antarctic waters, ice floes created rapidly by wind can be a major problem for killer whales, sometimes forcing them to remain in small, narrow areas of water for considerable periods of time. [

Voice

If humpbacks are the "singers" of cetaceans and belugas the "canaries of the sea," then killer whales are the "masters of language" of cetaceans. "It can make 62 different sounds, and these sounds have different meanings. For example, when feeding on fish, it will emit an intermittent "sneeze" sound, as if pulling hard on the hinges of a rusty iron door or window, and the fish will become unhinged after being terrorized by this sound. Killer whales are not only able to emit ultrasonic waves and search for fish through echoes, but they are also able to judge the size of fish and the direction they are swimming in through ultrasonic waves. This ability, which is important for predators living in the ocean, is very dark beneath the water, making it difficult to see distant prey targets in this environment.

Clusters

Killer whales prefer to live in groups, ranging from small groups of 2-3 to large groups of 40-50, and always spend 2-3 hours a day quietly at the surface of the water, able to float peacefully on the surface with their huge dorsal fins exposed because their lungs are filled with enough air. The pectoral fins of group members often remain in contact with each other, appearing affectionate and united. If a member of the group is injured or loses consciousness in an accident, the other members will come to their aid and support them with their bodies or heads so that they can continue to float on the surface of the sea, that is, they are also tied up in a pile when they are sleeping, which is to take care of each other and to maintain a certain degree of wakefulness. They travel together, use food, are socially organized in populations, rest in vast families, and rely on each other to survive and grow up.

Social Ancestry

The basic social unit of sedentary killer whales in Washington State and British Columbia is the small matrilineal group, typically consisting of two to nine orcas that are closely related, which remains solid for long periods of time, and where all members seem to **** share parenting duties. Several such groups may **** together to form a small group (a term often used to describe a group of cetaceans that associate socially with each other). A typical group usually contains adult and immature orcas of both sexes and their calves, with the oldest female leading the group, and the males in the group usually being the females' offspring. There are even male orcas up to 9 meters long that still live in small groups.

Killer whales are matrilineal in their social patterns, and the selection of mating partners is more complex, and is not determined by the power of the males: for example, the matriarchs of the group sometimes live to be 80 years old, and there are instances of mating in their later years, and their choice of mating partners is usually the older males within the group. The criteria by which female whales choose their mates are not clear to scientists, and the mating scene is rarely observed; only the mother is known, not where the father is.

There is no paternity or paternity within the whale group, the responsibility of the male is to go out and look for food, and then guide the group to hunt collectively, the division of labor is clear, there is no status; while the mother-daughter, mother-son relationship is very stable, is a lifelong relationship, and generally will not leave the group. The reason for the presence of orphan whales is usually injury or getting lost. When the group gets too big, it will "split up" and create a new group.

Hunting

Sometimes killer whales hunt in groups, using ultrasound waves emitted from their rumps (the part of the dolphin family used to create echolocation, which concentrates sound into a beam) to communicate with each other and strategize tactics. They also combine their efforts to concentrate schools of fish into a large ball, which they then take turns burrowing into for food. When hunting fur seals, killer whales will observe the cracked ditch that leads directly to the beach before the full tide, when the ditch fills with water at full tide and forms a shallow area on the beach, at this time the killer whales will rush along the ditch to the beach and intentionally strand themselves to take advantage of the opportunity to feed on the fur seals or sea lions, sometimes an orca will show its large dorsal fin to attract the attention of the fur seals, then the other orca will quietly approach to hunt the fur seals and when the prey escape, the other orca will rush up to them and kill the fur seals. When the prey escapes, another orca rushes forward to take over the hunt. Similarly, the killer whale will sometimes belly up, floating motionless on the surface of the sea, very much like a dead body, and when the squid, seabirds, sea animals, etc. close to it, it will suddenly turn over, open its mouth to eat them, and sometimes also with the tail of the prey will be knocked out, such as sea lions, and then foraging.

The orca's diet consists of fish, other cetaceans, finfoots, sea otters, birds, reptiles and cephalopods. Of the 362 stomachs of killer whales collected in the Antarctic, 217 contained fish, 75 contained remnants of minke whales, 35 contained fin-footed animals and 35 contained cephalopods.

Killer whales have highly developed brains as well as powerful bodies, and with these advantages, these highly intelligent animals are able to chase and kill many of the ocean's top predators. Some orca family members have at least nine shark delicacies on their menus, including the great white and mackerel sharks, which are feared by many animals.

Dr. Ingrid Vissar, an orca expert who has studied orca behavior for 17 years, said, "The most impressive tactic is to perform the palm chop from karate." Killer whales will use their tails to drive sharks out of the water, the whole time without even having to make physical contact with the shark. With the upward force generated by their tails, they are able to create a vortex that places the shark on top of the current created by their movement. Once the prey is out of the water, the killer whales turn their bodies and stick their tails out of the water, then attack the shark like a palm chop in karate.

After the shark is stunned, the killer whale grabs it and flips it over. This is clearly an unbelievable strategy, showing that the orca knows its opponent very well. After being quickly flipped upside down, the shark goes into a state of paralysis, known as "muscular dystonia," and is left for dead.

Vissar, from Tutukaka, North Island, New Zealand, said: "Killer whales don't understand the physiology of sharks, but the behavior they show does show that they know what happens when they take a definite action. You don't have to know how a car works in order to drive it, all you have to know is what you have to do to get it going. Similarly, orcas seem to know that once a shark is flipped over, they are incapable of fighting back. What orcas do is use their strengths to their advantage." Among other attack techniques scientists have observed in killer whales are "roundups," in which a pod of whales surrounds a lone shark and then moves in head-on, or creeps in from below and quickly strikes the shark in the lower abdomen before it can take advantage of the situation.

Visser said: "Usually, the killer whales will flip the sharks over so that the sharks can no longer fight back, so a successful hunt is over, and all they have to do is enjoy the fruits of their labor. We don't think orcas make special plans to go out and kill sharks. Foraging for food in the ocean is not an easy task, and they are relentless in their attacks on sharks once the opportunity presents itself."

Range

Distributed in Albania, Algeria, American Samoa, Anguilla Antarctica, Antigua and Barbuda, Argentina, Aruba, Australia, Bahamas, Bangladesh, Barbados, Belize, Benin, Bermuda, Brazil, British Indian Ocean Territory, Brunei, Cambodia, Cameroon Canada, Cape Verde, Cayman Islands, Chile, China, Cocos Islands, Colombia, Comoros, Congo, Democratic Republic of the Congo***, Cook Islands, Costa Rica, C?te d'Ivoire, Cuba, Denmark, Djibouti, Dominica, Ecuador (Colón Islands), El Salvador, Equatorial Guinea, Falkland Islands (Malvinas), Faroe Islands, Fiji, France, French Guiana, French Polynesia, Gabon, Gambia Ghana, Gibraltar Greenland, Grenada, Guadeloupe, Guam, Guatemala, Guinea, Guinea-Bissau, Guyana, Haiti, Heard Island and McDonald Islands, Honduras, Iceland, India, Indonesia, Iran (Islamic***nation of), Ireland, Israel, Italy, Jamaica Japan, Kenya, Kiribati, Liberia, Madagascar, Malaysia, Maldives, Marshall Islands, Mauritania, Mexico, Micronesia (Federated States of), Monaco, Morocco, Mozambique, Myanmar, Namibia, Nauru, Netherlands, Netherlands Antilles, New Caledonia, New Zealand, Nicaragua, Nigeria, Niue, Northern Mariana Islands, Norway, Oman, Pakistan, Palau, Panama, Papua New Guinea, Peru, Philippines Pitcairn, Portugal, Puerto Rico, Russian Federation, Saint Helena, Ascension Island and Tristan da Cunha, Saint Kitts and Nevis, Saint Lucia, Saint Pierre and Miquelon, Saint Vincent and the Grenadines, Samoa, Senegal, Sierra Leone, Singapore, Solomon Islands, Somalia, South Africa, South Georgia and the South Sandwich Islands, Spain, Sri Lanka, Suriname, Svalbard and Jan Mayen Islands, United **** and States of Tanzania, Thailand, Timor-Leste, Togo, Tonga, Trinidad and Tobago, Tunisia, United Arab Emirates, United Kingdom, United States of America (Aleutian Islands, Hawaii), Uruguay, Vanuatu, Venezuela, Viet Nam, Virgin Islands, Wallis and Futuna Islands, Western Sahara, Yemen.

Breeding

Killer whales can mate throughout the year, females give birth every 3-5 years, pregnancy lasts 1 year, each litter gives birth to 1 calf, lactation also takes about 1 year, and life expectancy is about 20-5 years. In the first 1-2 years after birth, the cubs can only make a coarse and harsh sound when they are hungry or call out to the female. Later, as they grow older, they gradually imitate the adult's voice, improving and enriching their own calls, but because of the complexity and variability of the orca's language, it takes at least five years for the cubs to fully master the adult's "language".

Killer whales are polygamous. In the Pacific Northwest, most mate between May and July. In the northeast Pacific, they mostly calve between October and March. Sexually mature males are 5.2-6.2 meters long and females are 4.6-5.4 meters long. Females give birth to their first viable calf between 11-16 years, and the smallest newborn calf recorded in the North Pacific was 2.28 meters long. The calving interval is about 5 years. Females stop calving at about 40 years of age, after which the reproductive period averages about 10 years and can extend to more than 30 years. The average lifespan is estimated to be 80-90 years. Males reach sexual maturity at about 15 years of age, with an average lifespan of about 29 years and a maximum lifespan of about 50-60 years. [

Subspecies differentiation edited

U.S. researchers recently reported in the journal Genome Research that they have discovered at least three new killer whale species after sequencing the mitochondrial DNA of killer whales, suggesting that more than one species of killer whale exists in the global ocean.

In the new study, the researchers sequenced the mitochondrial DNA of 139 killer whales using "highly parallel sequencing technology. The whales came from the North Atlantic, the North Pacific, and the waters off the Antarctic continent. The researchers ultimately found that two species of killer whales living in Antarctic waters that feed primarily on fish and seals, respectively, may be new species, and that new populations of killer whales also exist in the North Pacific.

Philip Morin, a geneticist at the National Oceanic and Atmospheric Administration who led the study, said that like other cetaceans, mitochondria in killer whales rarely change over time, making it difficult to find newly evolved killer whale species without looking at the entire genome. But using "highly parallel sequencing technology," it is possible to sequence the genomes of killer whale mitochondria by measuring tissue samples from around the world to identify new species.

Population status

Historically, orcas were hunted directly in Japan, Norway, and the former Soviet Union. There is no longer a direct fishery for killer whales, but the rise of orca shows in aquariums in the 1960s led to the rapid development of a live fishery for killer whales. With the development of breeding techniques for orcas, the demand for live capture has declined. Pollution from oil spills and other toxic substances at sea poses some threats to the health of orcas, and disturbance of orca prey by marine traffic is a potential impact. There are an estimated 70,000 orcas in the Antarctic, and only a few sporadic population surveys of orcas in other seas.

The orcas are not in danger of extinction, but man-made hunting may have caused the decline of some populations in some areas. There are only a few hundred orcas left, both resident and transient, in Washington state and British Columbia, and they are threatened by pollution, heavy boat traffic, and declining prey. Intensive whale watching may disrupt the lives of orcas, and those who work to protect salmon farms from threats such as fin-footed vessel traffic and declining prey. Intensive whale watching may disrupt the lives of orcas, and those who work to protect salmon farms from driving finfoots and reduced prey may be driven out of their preferred habitats. It is estimated that there are about 8,500 killer whales in the eastern tropical Pacific, at least 850 in Alaskan waters, and possibly up to 2,000 or more off Japan, while there are about 8,000 orcas distributed in Antarctic waters during the summer, and possibly between a few hundred and a thousand or more in other areas of the distribution range. Whalers in Japan, Indonesia, Greenland and the West Indies continue to capture orcas, and although the numbers are small, the impact on local populations can be considerable.

Protection level

Listed on the IUCN Red List of Threatened Species 2013 ver 3.1 - Data Deficient (DD).

Breeding and domestication

Killer whales can be bred and domesticated in aquariums, and are both intelligent and obedient; they can also learn many skills and perform a variety of shows, the most exciting of which is the "welcome" show: with the ringing of a bell, the huge head comes out of the water, and swims towards the audience to show "welcome". "Welcome", or let the keeper ride on the back to run around, and even let the keeper put his head into its huge mouth, and did not move; "leaping to swallow the fish": break the water, open the mouth, jumped to a height of more than 5 meters, and swallowed a large fish hanging there; "speed swimming in the vertical jump": first swim quickly along the edge of the pool, breaking the waves, sometimes leaping out of the water; "called to come": hear the call signal, immediately swim over; "cat and mouse": Orca belly up, two pectoral fins exposed to the surface of the water, the handler sits on its chest, one hand holding its teeth, with the orca in the water after a few laps around, then jumped into the water, at which point the orca caught up with him from behind, once again carried him on his back, and repeated the action many times ....... In fact, orcas become so docile because people have mastered one of their weaknesses: once they leave their own kind and live alone, they become very timid. Of course, salmon, tuna and other delicacies are essential as rewards after a great show.

Because of their superior intelligence, killer whales have also been domesticated to accomplish some special tasks. For example, the U.S. Navy's Underwater Warfare Center in Hawaii spends millions of dollars each year to train an animal troop of which the killer whales are one of the main members to do deep diving, navigation, demining, and other work. People also train orcas to salvage undersea relics, play the sound of orcas to scare away vermin in the sea water, or use it as a police dog in the sea, guarding and managing artificially farmed fish and so on.