Killer Whale (Orcinus orca)
Description
Orcas are quite distinctive in appearance - black back with white chest and sides and white patch above and behind the eye. They have a large dorsal fin with a grey saddle patch behind.
Behaviour
They are sophisticated social animals which travel in large groups and often work together to catch food. Like dolphins they communicate using a series of clicks and whistles. Resident populations can be seen in groups with other whales and dolphins.
Size
They can grow 5-7 m in length and weigh over 7 tonnes. Calves when born are about 2.4 m in length and weigh 180 kg.
When to see them
All year round
What they eat
Resident populations will eat many different species of fish whereas transient populations eat marine mammals and sharks.
Status
Listed as Lower Risk on the IUCN Red List but are also protected in UK waters by the Wildlife and Countryside Act 1981.
Distribution
They are found in all oceans but prefer the temperate and cooler areas including cold water up-wellings. They have seen to prefer the coastal waters than the open ocean.
Threats
They are threatened by pollution, depletion of prey species and conflicts with fishing vessels. Until 1981 they were also hunted when larger species were not available.
Fascinating facts
Orcas are the fastest marine mammals. They will travel over 160 km in one day and need an average of 227 kg food a day.