Killer whales are large aquatic mammals with a wide habitat and stunning black and white color. Killer whales are also called orcas and they belong to the family of dolphins, i.e. Delphinidae. They are the largest sized member of the Delphinidae family and belong to the suborder of toothed whales. The scientific name of killer whale is Orcinus orca.
Killer whales have a very wide distribution range and found in most of the oceans of the world, starting from arctic waters to tropical waters. They are found near the coast and also in the deep sea.
The name killer whale came from their behavior of killing other species of whales, dolphins, etc. Killer whale means ‘killer of whales’.
The dorsal side of their body and the fins are strikingly black. The ventral region is white in color. Male killer whales can be easily identified with their large dorsal fins that are 1.8 to 2 meters in height. Killer whales are around 8.5 meters in length and the weight varies from 3000 to 5000 kilograms. The male killer whales are larger than the females. The teeth of the killer whale are sharp, cone shaped and 20 in number. Killer whales have large flippers like dolphins, which help them to swim very fast.
Killer whales are social animals. Killer whales live in groups, which are called pods. A pod includes whales, which are related directly. The advantage of living in a pod is protecting the young and helping with the hunt. Killer whales communicate with each other through clicks and whistles. Their highly developed communication skill helps them in hunting other animals. They use echolocation to locate the prey. Killer whale releases a sound wave of very high frequency, which is reflected back from the body of the prey. This property of echolocation helps the killer whale to find its food.
Killer whales primarily feed on cod, salmon, squids, octopus, porpoises, birds, turtles, etc. They also feed on seals and penguins in the Antarctic region. Killer whales are apex predators, and can attack and prey on other species of whales and sharks.
Killer whales generally breed in warm water between winter and spring. They have a gestation period of 16 months. Each killer whale generally gives birth to one calf. The calves can swim beside the mother and they are nursed for a year or more.
Human activity has considerably decreased the number of killer whales in their wild habitat. Whalers have threatened their existence by killing them all over the world. Pollution is another major factor disturbing their existence. Oil spills and pollution by PCBs (Polychlorinated Biphenyls) are killing killer whales everyday. It has become necessary to help and protect the killer whales from environmental and human activity.