Born Free Foundation - Keep Wildlife in the Wild


Also known as the killer whale, the orca is the largest member of the dolphin family. They are one of the most distinctive and recognisable aquatic mammals with their striking black and white markings. They are black on the upper parts, usually with a light grey ‘saddle patch’ behind the dorsal fin, and white on the under parts and in a patch behind each eye.  Their dorsal fin is the tallest of all whale species, and can reach 2m high in males. It is straighter than the female’s dorsal fin which often curves backwards and is much smaller at around 70cm tall. Each orca has a unique dorsal fin and saddle pattern, which can be used to identify individuals. Killer whales are stocky in appearance compared to most whales which are more long and slim relative to their width.

Orcas make a wide variety of communicative sounds such as clicks, whistles, screeches and squeaks, and each pod emits its own distinctive sounds that its members will recognise.  Female orcas have been recorded teaching their calves their pod’s dialect in a simpler form, much like a human mother will teach her child to speak.

Often referred to as wolves of the sea, orcas live and hunt together in cooperative groups, much like a pack of wolves. They can cooperate to herd fish into a compact area so that they're easier to catch, hit ice flows from below to knock prey into the water, and work together to hunt whales much bigger than themselves or even great white sharks.  Killer whales spend around 14 hours a day foraging for food and can eat 220kg each day.  Orcas do not chew their food but eat it in chunks or can swallow smaller seals or walruses whole.  The number of teeth varies among individuals but they usually have between 40 and 56 teeth.  Each tooth is about 7.5 m long.

© Paul Spong

Orcas are usually born tail first and are already up to 2.5m long and 200kg in weight. When an orca is first born, its mother helps it swim to the surface for its first breath but within a short while can swim well on its own.

Today the greatest threat to the orca comes from the disturbance and degradation of its habitat by man. Disturbance and noise from boats and other man-made underwater activities such as drilling can disrupt orcas’ echolocation and social calls, which may affect their ability to hunt.  Overfishing of our seas also reduces their available food, and they can be accidentally caught in fishing nets. Sometimes fisheries will kill orcas intentionally as they see them as competitors. As it is a top predator, chemicals which are polluting Earth’s oceans build up within the whales as they eat the fish and other marine animals.  

Males: Bull
Females: Cow
Max speed: 30 mph
Body length: 6m - 9.8m
Weight: 5500kg- 9000kg
Age expectancy: 40-80 years, females live much longer
Diet: Fish, squid, seals, sea lions, dolphins, sea birds, turtles
Found in: Alaska, Mediterranean Sea, Gulf of Mexico
Habitat: Oceans of the world
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