Size: 5.5 - 9.8 m
Key feature: Dark colour with brilliant white patches
Behaviour: Fast and active
The Killer whale, or Orca, is one of the most familiar cetaceans. Contrary to what the name suggests the Killer whale is actually a dolphin, and is the largest member of the dolphin family. It is easily recognisable because of its distinctive black and white pattern. It has a dark colouration on its back with a white patch above it’s eye, a white chin and underbelly and a white/grey “saddle” behind it’s dorsal fin. The intensity of the black and white varies between different populations. The males have a recognisable tall, straight dorsal fin, whilst the females have a shorter, more curved fin.
Killer whales are sociable and inquisitive, travelling in groups of 2 – 50. They are fast and active, often demonstrating behaviour such as leaping, breaching, crashing and spy-hopping. They have a tall blow. Despite the nickname Killer whale, they have never been known to show aggression to humans in the wild, and rarely amongst themselves. The name originates from the nickname “Whale killer” given to them by fishermen after observing them hunting and scavenging larger whales in groups.
Killer whales have a global distribution and are one of the most widespread cetaceans. They are often found in shallow waters where they have been known to partially beach themselves to catch seals, but are also found in large numbers in deep offshore waters. They exist in different populations which rarely interbreed; it is possible that several species exist. In the UK they can be seen most regularly around the Shetland and Orkney Islands. They are occasionally encountered on the Bay of Biscay survey trips and their known range covers all of ORCA’s survey routes, although they are not frequently encountered.
Live killer whales were once captured in large numbers for aquariums and although there are still a number of individuals in captivity throughout the world this has declined significantly in the last two decades. They were kept in captivity for commercial and scientific purposes although several high profile fatal incidents involving marine mammal trainers over recent years have damaged the public perception of the industry. Currently they are at risk from pollution, chemicals from fertiliser run off and from oil spills which damage ocean habitats, depleting their prey. They also suffer when chemical contaminates build up lower down in the food chain, this level of pollution accumulates with each step up the food chain and when large numbers of contaminated prey are consumed by top predators, such as Killer whales, contaminants reach dangerous levels, affecting long term survival.