Description - Killer Whale
Sightings: Seasonally Common
Male Length: 2.6 m – Female Length: 7.9 m
Male Weight: 5,600+kg – Female Weight: 3,800+kg
Life Span: Male: 50 – 60 years – Female: 80 – 90 years
The killer whales body is extremely robust. The head is conical and lacks a well defined beak. The dorsal fin at the mid back is large and prominent and highly variable in shape. Falcate in females and juveniles, erect and almost spike like in adult males. In adult males the dorsal fin can reach heights of over 2 meters high where as in the females the dorsal is usually a maximum of 1 meter high. The flippers are large, broad and rounded, very different from the typically sickle-shaped flippers of most delphinids. There are 10 to 14 pairs of large pointed teeth in both the upper and lower jaws.
The colour pattern consists of highly contrasting areas of black and white. The white ventral zone continuous from the lower jaw to anus narrows between the all black flippers and branches behind the umbilicus. The ventral surface of the flukes and adjacent portion of the caudal peduncle are also white. The entire back and sides are black with the exception for white patches on the flanks that rise from the uro-genital region and prominent oval while patches slightly above and behind the eyes. All killer whales have a grey to white saddle patch clearly and directly behind the dorsal fin.
Range and Habitat:
Killer Whales are clearly cosmopolitan and are not limited by such habitat features as water temperature or depth. Where there is an-abundance of prey there is usually Killer Whales, although its movements generally appear to track those favoured prey species or to take advantage of pulses in prey abundance or vulnerability such as areas with spawning grounds and seal pupping.
In the Antarctic during summer, most killer whales position themselves near the ice edge and in channels within the pack ice where they prey on baleen whales, penguins, seals and other birds.
Researchers in British Columbia have identified distinct differences in two different family’s of Killer Whales, they have been segregated into resident pods and transient pods, both with different and clearly defined habits, with both species occupying large ranges, however the resident pods tend to be more habitual in their migration.
The Resident pods of killer whales off the Coast of British Columbia maintain a strong matriarchal society, consisting of two or four generations of two to nine related individuals. These groups are stable over long periods of time and all the members may contribute to calf rearing. The largest resident pods in the inside passage is known to have 60 individuals. While adult females tend to be associated with one or more pods, adult males are sometimes solitary. Known to breach, spy hop and slap the surface with their flukes or flippers these beautiful creatures are quite the sight to behold.
Transient pods rarely have more than three members, who seem to be together to hunt. They do not mingle with the resident pods; it has been recorded that many of the resident whales will leave an area if the transients are approaching.
With the resident population, calving occurs year round, with a peak between autumn and spring. The average calving interval is five years. Females usually stop reproducing after 40 years of age. Studies of whales in captivity suggest that the gestation lasts 15 to 18 months. The young begin eating solid food at a very young age; however they do continue to nurse for at least a year and may not be fully weaned until close to two years of age.
Food and Foraging:
Transient killer whales eat a diet ranging from small schooling fish and squid to large baleen and sperm whales, they have also been found with birds, sea lions and dolphins in their stomachs there have even been accounts of sharks, rays and even deer or moose which they can catch swimming across channels. Killer whales obviously use cooperative hunting habits to harass and subdue large prey.
The resident pods tend to specialise in their eating habits, with a preference almost exclusively for salmon and if given the choice Chinook salmon. Operating in a consolidated group to maintain tight balls of bait fish taking turns slicing through the schools to feed, with the young being in training and given the opportunity to go first.
Status and Conservation:
Although not considered endangered, whaling or live capture operations have depleted some regional populations. Local populations number only in the low hundreds and are threatened by pollution, heavy ship traffic and possibly reduced prey abundance.