What is the information about orcas?

Orcas are a kind of whales, which are large marine mammals of the genus orcas of the dolphin family, also known as orcas and killer whales. Their habitats are mainly in polar and temperate waters, and are widely distributed in the waters of Japan, North Sea and Iceland all over the world. There seems to be no obvious restriction on water temperature, depth and other factors. There is a very high habitat density in high latitudes. Let's take a look at the data of orcas.

Morphological characteristics of orcas

The largest adult male of orcas is 9.75m long and weighs 9524 kilograms, making it the largest species in the dolphin family. Orcas have obvious sexual dimorphism in body size, flipper size and dorsal fin height, with a maximum body length of 7.70 meters for females and 9 meters for males. The dorsal fin of the male adult is erect, up to 1.0 to 1.8 meters high, while the female dorsal fin is obviously sickle-shaped, less than 0.7 meters high. The head is slightly rounded, with an inconspicuous beak. The back of the body is black, there is a light gray Sellar spot behind the dorsal fin, the lower jaw and the ventral surface of the body from the anterior mandible to the urogenital area are white, there is a white leafy spot extending upward from the urogenital area to the posterior side of the dorsal fin, the ventral surface of the caudal lobe is white or light gray, and there may be a black edge, and there is a white oval spot on each side of the eye. Sellar spot is not obvious when young, but more significant after sexual maturity.

Feeding habits of orcas

Orcas feed on fish, other cetaceans, flippers, sea otters, birds, reptiles and cephalopods. Of the 362 stomachs of orcas collected in Antarctica, 217 contain fish, 75 contain remnants of minke whales, 35 contain fins and 35 contain cephalopods. With a well-developed brain and powerful bodies, these highly intelligent animals are able to chase and kill many of the top predators in the ocean, and some orcas have at least nine kinds of shark delicacies on their menus, including great white sharks and mackerel sharks that frighten many animals.

The sound system of orcas

If the humpback whale is the "singer" of whales and the beluga whale is the "canary" of the sea, then the orca is the "language master" of cetaceans, it can make 62 different sounds, and these sounds have different meanings. For example, when preying on fish, there will be an intermittent "how to sneeze" sound, just like the sound of tugging at the hinges of rusty iron doors and windows. After being threatened by this sound, the fish will become abnormal. Orcas can not only emit ultrasonic waves and find schools of fish through echoes, but also judge the size of schools of fish and the direction of swimming through ultrasonic waves. This ability is very important for predators living in the ocean. It is very dark under the sea. It is difficult to see distant prey targets in this environment.

The herding habits of orcas

Orcas like to live in groups, ranging from a small group of 2 to 3 to a large group of 40 to 50. They spend 2 to 3 hours a day quietly on the surface of the water. Because their lungs are filled with enough air, they can float safely on the surface of the sea, revealing their huge dorsal fins. The pectoral fins of the group members often keep in touch, showing intimacy and unity. If a member of the group is injured or loses consciousness in an accident, other members will come to help, with a top support attached to the body or head, so that they can continue to float on the sea, even when they sleep. This is to take care of each other, and maintain a certain degree of sobriety, travel together, eat together, take the population as a social organization, rest in the vast number of families, and rely on each other to survive and grow up.

The social ancestry of orcas

The social form of orcas is matrilineal, and the choice of mating objects is more complicated, and everything is not determined by the strength of males. For example, the patriarch of a group of whales can sometimes live to be 80 years old, and there are also examples of mating in their later years. The objects they choose to mate are generally older males within the herd. The standard scientists of the female whales are not clear. They rarely observe the scene of mating, only know the mother, and do not know where the father is. There is no father-son relationship or father-daughter relationship in the whale herd. The responsibility of the male is to go out to find food and then lead the whale group to hunt collectively. The division of labor is clear and there is no status, while the mother-child relationship is very stable and is a lifelong relationship. The reason for the emergence of a lone whale is usually injured or lost. When the population is too large, it will be "separated" and a new group will be created.

Breeding habits of orcas

Orcas can mate all year round. The female gives birth every 3 to 5 years, the gestation period is 1 year, and each baby gives birth to 1 calf, and the lactation period takes about 1 year. Within 1-2 years after birth, the cubs can only make harsh sounds when they are hungry or calling the female. Later, with the increase of age, they gradually imitate the adult voice, improve and enrich their own calls, but because of the complexity of orca language and changeful. It takes at least 5 years for the young to fully master the adult "language". The female stops giving birth at about 40 years old, and then the average reproductive period is about 10 years, which can be extended to more than 30 years, and the average life expectancy is estimated to be 80 ~ 90 years. Males reach sexual maturity at about 15 years old, with an average life span of about 29 years and a maximum life span of about 50 years.