|Size:||Length: 25 to 32 feet (7.6 to 9.75 m)|
|Weight:||12,000 to 19,800 pounds (5443 to 8981 kg)|
|Diet:||Whales, seals, sharks, sea lions, sea turtles, salmon, cod, herring, penguins and squid|
|Distribution:||Oceans and seas around the world|
|Young:||1 to 3 calves every 3 to 10 years|
|IUCN Status:||Lower Risk, Conservation Dependent|
|Terms:||Young: Calf Group: Pod|
|Lifespan:||50 to 100 years in the wild, but in captivity they live only a fraction of their normal lifespan|
· Orcas are the largest members of the dolphin family, so they are not technically whales.
· The male orca’s dorsal fin is as tall as a man.
· The most famous orca is Keiko, star of the movie Free Willy.
Orcas have mostly black skin with distinctive white patches. They have a stocky body and a rounded head with a distinctive beak. There is one blowhole located at the top of their head and a tall dorsal fin. Their flippers are large and paddle-like. The dorsal fin of the male is taller, more triangular and more upright than that of the female. They have a total of 40 to 50 large, conical, enamelled teeth distributed in both the upper and lower jaws.
Orcas migrate towards the warm waters of the equator in search of food, but they prefer cold waters and return north as soon as the food supply becomes abundant once more. They will approach the shore when attracted by food resources but they always return to oceanic waters.
Their diets consist of whales, seals, sharks, sea lions, sea turtles, salmon, cod, herring, penguins, and squid. The pods search for food together and will work as a unit to find prey. An average-sized orca eats about 550 pounds (250 kg) of food a day.
Although females are smaller than males, they are the dominant family pod members. Females give birth every three to 10 years to one calf, approximately eight feet (2.4 m) in length and weighing around 400 pounds (181 kg). The gestation period of the female lasts 16 months. The calf will not be weaned until after it has reached its first birthday. Offspring usually stay with their mothers for many years.
Whales are highly intelligent, very social mammals that live in pods—small family groups of five to 50 related whales who stay together for life. Each pod contains one adult male, several adult breeding females and a number of sub-adults of both genders. Behavioural studies in Canada have shown that there are two types of pods: residents and transients. Transients form smaller pods of between one to seven individuals, roaming over a large area and feeding mainly on mammals. They vocalise less frequently, often change direction abruptly when swimming, and remain underwater for up to 15 minutes at a time. Residents, on the other hand, form larger pods, have smaller home ranges and feed mainly on fish. They vocalise frequently, keep to predictable routes, and rarely stay underwater for more than four minutes. Orca vocalisations include clicks, whistles and scream-like pulses. The sounds are used to communicate with other orcas for mating purposes and for locating prey. Orcas hunt in groups. They are also called “killer whales” because they kill seals and whales, but for some, this name is misleading as there has never been a case of orcas killing a human. Both in captivity and the wild, they are non-threatening towards humans and even in self-defence, have never attacked a man. Orcas travel great distances each day, swimming up to 62 miles (100 km). They can dive hundreds of feet below the water’s surface while searching for food. Orcas also exhibit behaviours such as “spy-hopping,” in which they poke their head out of the water, and tail-slapping, in which they come up partially and on the way back down slap their tail fins—called flukes—against the water’s surface.
Orcas have become at risk and there are organizations made up of marine mammal experts who are working to end the captivity of marine mammals. Many orcas die in captive environments because they are kept in small pens where they can only swim in tiny circles, and they are separated from their families. Captive orcas have flaccid dorsal fins, an indicator of their unhappiness and failing health. The northeast Pacific orca southern resident population is considered Endangered by Environment Canada. The Northeast Pacific northern resident and transient populations are listed as Threatened by Environment Canada.