Killer Whales
One of the world’s largest animals, the Orca belongs to the Dolphin family. In Canadian waters, there are noted populations in the northern Pacific along British Columbia, and, though less commonly, in the Atlantic and Arctic regions.
Known as “aarluk” in Inuktitut, the Killer Whale (Orcinus Orca) is featured as Nature Canada’s calendar.
About the Killer Whale
One of the world’s largest animals, the Orca belongs to the Dolphin family (Delphinidae). Males can reach ten metres in length and 22,000 kilograms in weight. Females are smaller, but still considerable, at 8.5 metres long and 7,500 kilograms. Highly intelligent and distinctive for its black and white colouration, these magnificent creatures are also deadly. Poised at the top of the oceanic food chain, they are carnivores whose diet is often geographic and population specific. The Killer Whale’s menu could be fish heavy—such as salmon, herring, and tuna—or comprise larger marine life, such as seals, sea lions, penguins, sharks, and other whales and porpoises. Extremely social, Orcas live (and hunt) in matriarchal family pods typically comprising five to fifty whales and use echolocation to communicate. Killer Whales are distributed throughout the world, from the polar ice caps to the tropics near the Equator. In Canadian waters, there are noted populations in the northern Pacific along British Columbia, and, though less commonly, in the Atlantic and Arctic regions. In recent years, however, this has begun to change, as sea ice both recedes and occurs for shorter times each year.Heading North and Staying There
One consequence of increasing melting and retreating ice and the growing unpredictability of ice formation schedules is the change in roaming patterns of Killer Whales, who now venture into far northern waters where they previously did not. Killer Whales typically avoid ice because of their high dorsal fins. With the loss of year-round sea ice in the Arctic, however, these cetaceans, once largely absent from the region, are now both spending more time there and going to areas that were formerly inaccessible due to permanent or seasonal ice cover. For example, Killer Whale sightings, once rare in Hudson Bay, have been reported not only during summer months but in winter as well.
A Killer Whale surfaces in the Strait of Georgia. Image courtesy of Gary Sutton.
Up north, the whales can miscalculate when the water will freeze and become trapped in ice, like what happened near the small northern Quebec village of Inukjuak in January 2013. A pod of a dozen Orcas became stuck, stranded in an opening of water just ten feet wide in northeastern Hudson Bay. Visibly stressed, the whales thrashed and took frantic turns surfacing for oxygen. Fortunately for them, the weather changed, causing the ice to break, and they were able to escape. The incident called attention to the shifting patterns of Arctic freezing due to climate change.
