Killer whales are found all over the world, from the Antarctic to Alaska and New Zealand to Russia. They live in communities that are totally separate from one another, which means Alaskan orca are not hanging out with their Kiwi relatives. Despite this separation, killer whales around the world are still considered to be part of a single species.
Orca communities are divided into ten distinct populations referred to as “ecotypes” (five in the southern hemisphere, and five in the northern hemisphere). First let’s explore the killer whales found in the southern hemisphere – they may be different than what you expect!
1. Antarctic Type A – The Big Game Hunters
Antarctic Type A whales are mammal eaters. While in Antarctica during the summer, they mainly feast on minke whales and some southern elephant seals. Hunting prey like these is an impressive feat; southern elephant seals are the largest seals on Earth, weight up to 8,800 lbs (4,000 kg). Minke whales are the smallest baleen whale but can still be almost 10m (32 ft) long and weigh up to 9,000 kg (20,000 lbs). Their success in hunting these great animals may be due to their own large size. Type A killer whales can be up to 31 feet long (9.5 meters)! They prefer the open waters of the Southern Ocean and migrate in and out of the Antarctic to follow their prey.
2. Pack Ice (Large Type B) – The Wave-Washers
Pack ice orcas are famous for their ability to wave-wash seals off floating ice. They work as a group to create a strong enough wave with their tails to tip the seals into the water, and right into their mouths. They are commonly found in area’s with loose pack ice, and enjoy dining on Weddell seals. These killer whales are large with a big eye patch. The black portion of their bodies is two shades of grey, but their most noticeable feature is the overall yellow tint of their bodies due to a layer of diatoms (a type of algae).
3. Gerlache (Small Type B) – The Penguin Destroyers
Gerlache killer whales are like their larger counterpart in colouration (including yellow diatom growth), but they are smaller in size. Their name comes from the Gerlache Strait (near the Antarctic Peninsula), where they are commonly seen. They have been seen hunting penguins, but their preferred food is not yet known.
4. Ross Sea (Type C) – The Evil Cartoon Character
These orcas are the smallest ecotype. Males only reach about 6 meters (20 feet) long. Their eye patch is slanted and narrow, giving them the look of a villain in a Disney movie, and they too might sport diatomaceous growth and a yellow hue. Unlike their Type A and Type B relatives, these whales are fish eaters, and live in the thick pack ice of the Ross Sea off Eastern Antarctica.
5. Subantarctic (Type D) – The Unicorns
These are the most seldom seen and mysterious of the orca ecotypes. Type D killer whales are a rarity – they have only been glimpsed about a dozen times. They were only discovered in the 1950s when several of them were found stranded in New Zealand. Their most noticeable difference from other types is their tiny slit-like eyepatch. There is still much to discover about Type D killer whales and their diet, but they seem to enjoy stealing fish off long-lines!
Check out these links to learn more about orca ecotypes!
Feature Photo: Lili Wilson