We explain what an orca is, what its habitat is, its diet, reproduction and other characteristics. Also, how dangerous are they.
What is an orca?
It is known as orca or orca whale to a marine mammal of the order of cetaceans and from the same family as dolphins (Delphinidae), common in all the world’s oceans. Its body is recognizable for its black (on the back) and white (on the belly) coloration, as well as for being one of the largest and most versatile marine predators in the world.
Scientific name Orcinus orca, this is the largest known dolphin species. The species evolved in the Pliocene, around 5.3 million years ago, moving away from the ancestors of today’s dolphins.
It has a reputation for being a fearsome predator, capable of killing other large carnivores such as the white shark, and at the same time of being a meek and intelligent animal capable of relating, in captivity, in an affectionate way with humans.
Killer whale hunting was common in 18th century Japan, while the large whaling industries ignored them, given the low amount of oil that can be extracted from their bodies, compared to whales and sperm whales.
Since the end of the 20th century, on the other hand, the sighting of killer whales has become an important tourist attraction, as well as its breeding in captivity and its incorporation into aquatic shows, since it is a fairly intelligent animal. Captivity produces dorsal fin atrophy in this species, due to the lack of exercise of his dorsal muscles, by constantly staying on the surface.
See also: Aquatic animals
Killer whale characteristics
Orcas, in general, are characterized by the following:
- They are marine mammals, adapted to submerged life, of characteristic black and white body, endowed with hydrodynamic proportions.
- Males of the species they can be about 9 meters long and weigh about 5.5 tons, while the females range around 7.7 meters in length and 4 tons in weight. Both sexes have an extensive dorsal fin that can reach 1.8 meters in length.
- It is a marine super predator born, without rivals or natural enemies, which uses echolocation (emitting sound under water) to perceive its prey.
- They are migratory animals, which make up more or less extensive herds, capable of coordinating an attack on larger prey, such as whales or white sharks.
- Four different types have been identified killer whales, whose physical distinctions are more or less obvious, and which could indicate that new species have formed over time. It is a species under intense study by marine biologists.
- They are highly intelligent animals, among the few able to recognize themselves in a mirror. They are capable of playing, of imitating other animals and of transmitting teachings to their offspring.
Where do orcas live?
Orcas have a presence in absolutely all the oceans of the world, from the cold waters of the polar oceans, to the warm waters of the tropics. They are animals of much and continuous movement, being able to swim up to 60 kilometers per day and dive to depths of 150 meters repeatedly.
What do killer whales eat?
The diet of killer whales is strictly carnivorous, and among its usual prey are salmon, tuna, herring, rays, cod, squid, penguins, whales, sharks and even other marine mammals, such as seals, porpoises, sea lions and dolphins. The human being is not among its usual prey.
How do killer whales reproduce?
As in all mammals, Killer whale reproduction is sexual and viviparousBut unfortunately not much is known about the reproductive habits of wild killer whales.
From the study of specimens in captivity, it is known that they are a polygamous species, whose periods of heat are variable and unpredictable, depending on the individual, and that their gestation period lasts between fifteen and eighteen months, at the end of which a single calf per parturition is given at any time of the year.
How long do orcas live?
The average lifespan of an orca is comparable to that of a human being. Once the risk stages of infancy (when about 37-50% of the calves die), killer whales They can lead lives of between 60 and 80 years for males and almost 100 years for females. Like humans, female killer whales suffer from the end of ovulation and reproductive life (menopause) after a certain age.
How dangerous are killer whales?
There are records of killer whale attacks on human beings, generally accidental, as a result of confusion (a surfer who resembles a seal) or stress due to situations typical of captivity.
Nevertheless, the human being does not appear among the habitual prey of the killer whaleRather, they tend to be curious and playful when interacting with human beings, as long as they do not represent any immediate danger to them, of course.
A famous case of a particularly aggressive killer whale was that of Tilikum, an Icelandic killer whale that was involved in the deaths of three of his SeaWorld trainers in the United States. His story is told in the documentary Blackfish, of 2013.