Orca killer whale
Common Name:Killer whale
Latin Name:Orcinus orca
Other Names:Killer Whale, Grampus
Primary Classification:Odontocete (Toothed whale, dolphin or porpoise)
Sub Classification:Delphinidae
Description:
Killer whales (orcas) are large, stocky, and heavy! Their jet black, white and grey markings, and the males' very tall dorsal fin, make them hard to muddle up with other species. In fact, a male's dorsal fin can be as tall as a man, up to 1.8m (6ft) high! It is the tallest dorsal fin in the animal kingdom. Females have a much smaller fin, theirs is only about half the size and is more curved. Young calves can be a little trickier to identify as their saddle-patch (the patch behind the dorsal fin) can be quite dark and therefore blend into the rest of their bodies; and their light patches (behind the eyes and on the belly) can look a bit pink or rusty coloured. Researchers use the dorsal fins to identify individual orcas. Different shapes, sizes, nicks and scars help them remember which whale is which. Saddle-patches are also unique to individual whales, no two orcas have exactly the same saddle-patch shape and pattern. Different orca populations vary slightly from one another. For example, those living in the Antarctic are smaller and their patches more yellowy then those in the north, and those off Australia and New Zealand are dark purplish-brown with ivory coloured patches. An orca has between 20 and 26 large sharp teeth in both upper and lower jaws; these curve backwards towards the throat and interlock when the whale closes its mouth. They are perfectly designed for catching and biting their food
Field ID:
Robust body, Single blowhole, Large paddle-like flippers, Black and white in colour, White chin, Grey saddle-patch, Tall dorsal fin, White patch behind eyes, Fast active swimmer
Length (metres):
Orcas are the largest of all the members of the dolphin family. Adults can range from approximately 5.5 to 9.8 metres (18 - 32.25 ft). Males are larger then females, they average 7 - 8 metres, females around 6 metres . New-borns are usually 2.1 to 2.5 metres (7 - 8.25 ft) long.
Weight:
Adults weigh anything from 2.6 to 9 tonnes (males are generally heavier then females) and new-borns are approximately 180 kg (395lb)
Diet:
Fish, Squid, Seabirds, Turtles, Sealions, Seals, Other cetaceans
Behaviour:
Residents tend to form large family groups or pods (usually 5-25 animals). They have relatively small home ranges (particularly in the summer) and feed mainly on salmon and other fish. They normally hunt using echolocation. Residents also 'talk' to one another more often than other orcas. They are the most studied of all the orcas, because they have predictable eating habits and are therefore relatively easy for scientists to find and follow. Transients tend to form smaller family groups or pods (usually 1-7 animals). They tend to roam over a much wider area and feed on seals, sealions, dolphins and other mammals, as well as seabirds and a variety of other wildlife. They do not hunt using echolocation, probably because their prey have good hearing and would be able to hear the orcas' clicking sounds. Instead they swim quietly, listening to sounds being made by other animals in the water. Transients 'talk' to one another less often then resident orcas and have slightly more pointed dorsal fins. Offshores were only identified for the first time in the early 1990s. They appear to travel in large groups of 25 or more. Most of their time is spent in the open sea, much further away from shore then either residents or transients. They probably eat mainly fish and make lots of noise, communicating with each other regularly. Orcas can be very acrobatic. They are known to breach, lobtail, flipper-slap and spy-hop.