What is an Orca or Killer Whale?
It is known as orca or orca whale or Killer Whale to a marine mammal of the order cetaceans and from the same family as dolphins (Delphinidae), common in all the world’s oceans. Its body is recognizable by 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 species of dolphin.
The species evolved in the Pliocene, about 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 for being a meek and intelligent animal capable of relating affectionately with humans in captivity. 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, orca sightings have become an important tourist attraction, as well as their breeding in captivity and their 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 their dorsal muscles, by constantly staying on the surface. See also: Dolphins
Characteristics of killer whales
Orcas, in general, are characterized by the following:
- They are marine mammals, adapted to submerged life, with a characteristic black and white body endowed with hydrodynamic proportions.
- The males of the species can grow up to 9 meters long. and weigh about 5.5 tons, while 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 apex predator born, without rivals or natural enemies, which uses echolocation (emitting sound underwater) to perceive its prey.
- They are migratory animals that makeup 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 of killer whales, whose physical distinctions are more or less evident, 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, imitating other animals, and transmitting lessons to their offspring.
Where do killer whales live?
Orcas are present in absolutely all the world’s oceans, from the cold waters of the polar oceans to the warm waters of the tropics. They are animals of great and continuous movement, being able to swim up to 60 kilometers a day and submerge to depths of 150 meters repeatedly.
What do killer whales eat?
The killer whale diet 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, Orca reproduction is sexual and viviparous., but unfortunately not much is known about the reproductive habits of wild killer whales. From the study of captive specimens, it is known that they are a polygamous species, whose periods of heat are variable and unpredictable depending on the individual, and that its gestation period lasts between fifteen and eighteen months, at the end of which it gives birth to a single offspring per delivery, at any time of the year.
How long do killer whales live?
The average lifespan of an orca is comparable to that of a human being. Once past the risk stages of infancy (when about 37-50% of calves die), killer whales can lead lives of between 60 and 80 years, in the case of males, and almost 100 years in the case of 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 orca attacks on humans, generally accidental, the result of confusion (a surfer who resembles a seal) or stress due to situations typical of captivity. Nevertheless, the human being is not among the usual prey of the killer whale, and rather these tend to be curious and playful when interacting with human beings, provided that they do not represent an immediate danger to them, of course. A famous case of a particularly aggressive orca was that of Tilikum, an Icelandic killer whale who was involved in the deaths of three of her SeaWorld trainers in the United States. Her story is told in the 2013 documentary Blackfish. Continues with: Octopus