Orcinus orca - The Killer Whale

Porpoise tooth and dolphin tooth.

Critically endangered maui dolphins

How are dolphins different from other cetaceans? For a start, dolphins have teeth and not baleen. Their teeth are conical, unlike those of the porpoises which are flat, spade-shaped affairs. They have a pronounced beak-like rostrum, and large, pointed dorsal fins. The smallest dolphins are the critically endangered Maui dolphins (Cephalorhynchus hectori maui), of which there are estimated to be fewer than 50 left, and only 10 of those female. Mauis are about 5.6ft long, so shorter than the average man. While this blog and its associated work will not seek to deal with dolphins in general, those dolphins whose common name includes 'whale' will be, and that includes, of course, the killer whale. The biggest of the dolphins, Orcinus orca, can get up to 31ft in length.

The Mouth of Orcus
in the Gardens of Bomarzo, Italy

The name Orca is a very old one. It is the Roman name for the god of the underworld, the equivalent to the Greek Hades and, like Hades, is also the name for the underworld itself. It probably goes back to the Etruscan empire, but it entered English as 'orc', which came to mean an evil spirit or daemon (incidentally where J.R.R.Tolkien got his name for the horrible creatures in The Lord of the Rings). Linnaeus named this animal Orcinus orca - creature from the land of Death - in 1758, but there have been a great many other names.

Orca attacking a huge adult humpback

The common name in English, killer whale, comes from the fact that some (though by no means all) orca attack and kill large whales,  and no other animal (except humans) has ever done that. However, orca seldom attack big animals, and even the dramatic attacks on seals that have been seen on natural history documentaries in recent years are relatively rare. One very bright individual at a marine park in Canada worked out that by regurgitating fish on to the side of the pool, he could attract sea birds and then kill and eat the birds, and other whales imitated this behaviour. Most of the time they hunt and eat fish, squid and other quite small prey. Powerful and clever killers though they may be. it seems to me that most carnivores kill other animals for food - the common name for Panthera leo is 'lion', not 'killer gazelle'! This is why I think the naming of these animals bears reconsideration.

Orca The Killer Whale
1977

Shape-shifting orca/wolf
Ed Kwong

Sculpture at the Canadian Museum
of History in Vancouver

Orca hold a special place in both traditional lore and modern popular culture. In some societies they are considered shape-shifters changing into wolves to come onto the land in Siberia, or changing into humans when beneath the waves off British Columbia. While in the USA, Hollywood has represented them as incredibly intelligent, yet vengeful in the film 'Orca the Killer Whale' (attributing to the eponymous orca some of the same hateful qualities that Melville gave the sperm whale Moby Dick), and highly emotional and very human in 'Free Willy', granting anthropomorphic qualities to the orca for which there is little hard evidence. Certainly they are intelligent animals, with complex social structures that rival the primates, and highly developed communication skills, but there is some quality about them that humans seem to find irresistible. They have appeared in stories and mythologies, poems and paintings, sculptures and films, perhaps more than any other cetacean, over thousands of years.

Vessel from the Nazca people of Peru

On a social level, the orca pod is usually a matrilineal family and has been described as the most stable of any animal species, with idiosyncratic vocalisations and hunting behaviours being passed down through generations within the family but not necessarily transmitted to other orca pods in an example of what is considered to be 'culture'. There are different types of orca and at some point in the not-too-distant future they may be defined as separate subspecies. The differences between these types is curious in itself. Those groups known as 'resident' live in large pods regularly in the same coastal waters and feed almost entirely on fish and occasional squid.

Close-knit orca pod

Free Willy 1993

'Transient' orca on the other hand, live in small groups and feed almost exclusively on marine mammals, from seals and walrus to other cetaceans. They live in smaller groups of up to about 6 individuals and are less socially cohesive than the residents. They also have far less complex and variable dialects. Though they occupy roughly the same regions of the North East Pacific from Alaska down to California, they tend to avoid each other and are thought not to have interbred from at least 10 000 years. A third, genetically distinct group, known as 'offshore', is also recognised. Little is known about them but as the name suggests, they usually stay far out to sea, hunting schooling fish. There are physiological differences between members of the different groups, most notably in the size and shape of the dorsal fins. If they can't be considered separate species now, they certainly will be given enough time.

From the journal of whaleman
Joseph Bogart Hersey circa 1846-1848

To hear the voice of the killer whale click here. There is a National Geographic film here. It's nice to see a cultural expression incorporating cetaceans with a little humour, too. Here is a cartoon by 'memeguy'