Orca Fact file

Infraorder: Cetacea

Parvorder: Odontoceti

Family: Delphinidae

Species: Orcinus orca

Common name: Killer whale, orca, orca whale, blackfish, Grampus, whale killer (historical)

Distribution: All oceans. Key places to see wild orcas include: Norway, Iceland, Scotland, Gibraltar, East Russia, South Africa, Argentina, SW Australia, New Zealand, West Canada, West USA, India, Sri Lanka, Japan, and Antarctica

Length: (Average) Males: 7-8m, females: 6m

Weight: (Average) Males: 3,600 - 5,500kg, females: 1,350 - 3,650kg

Longevity: Male (Average) Captivity: 10yrs/ Wild: 30-50yrs (Max.) Captivity: 43yrs / Wild: 60-70yrs // Female (Average) Captivity: 12yrs / Wild: 50yrs (Max.) Captivity: 56yrs / Wild: 80-100yrs

Sexual maturity: 10-15 yrs

Gestation: 17 months

Population:  Globally: 50,000 approximately // Southern Resident: 72 (J Pod: 22, K Pod: 17, L Pod: 32) / West Coast Community (UK): 8 (as of May 2020)

Conservation status: Data deficient

Eco-types

Orcas come in a wide range of shapes, colours and sizes. They have been divided into “ecotypes” however some are questioning whether they should be classified as different species.

Northern Hemisphere:

North Pacific:

(1) Residents: The most well-known orcas. Often have open saddle patches. Fish eaters.

(2) Transients/Biggs: Large. Travels in small groups. Quieter. Mammal eaters.

(3) Offshores: Found 24-40km offshore. Travel in large groups. Feeds on sharks. Worn teeth.

North Atlantic:

(4) Type 1: Found off Norway. Worn teeth.

(5) Type 2: Sloping eye patches. Mammal eaters.

Southern Hemisphere:

(6) Antarctic Type A: Mammal eaters.

(7) Pack Ice Large Type B: Very large eyepatches. Yellowish tinge. Mammal eaters.

(8) Gerlache Small Type B: Large eye patches. Yellowish tinge to greyish body. Penguin eaters.

(9) Ross Sea Type C: Narrow, slanted eye patches. Yellowish tinge to grey body. Fish eaters.

(10) Subantarctic Type D: Bulkier head shape, with tiny eye patches. Fish eaters.

Family

Orcas are highly complex and social beings. Depending on the eco-type, orcas travel in various group sizes. However, what is known about orca society is that orcas are matriarchal. Groups are made up of an adult female and her offspring and grandchildren. Sons will stay with their mothers all of their lives, only leaving to mate with other pods before returning. Male orcas do not rear their own offspring, but will help raise their siblings, nieces, nephews and cousins. Orcas are also one of the few animals that live past menopausal age. Female orcas continue into their ‘granny years’ to assist with rearing the younger generations. Orcas also have their own dialects, perhaps to distinguish non-related members to assist in avoiding inbreeding.

Prey

Again, depending on the ecotype, the prey of orcas differs. Some orcas are fish-only eaters. Others are mammal eaters. They may prey on seals and sea lions. Around Argentina, orcas will beach themselves to grab Patagonian sea lion pups from shore. In Antarctica, orcas will work together to knock seals off ice flows. Certain ecotypes in Antarctica feed on penguins as well. Alternatively, many orcas will hunt fellow cetaceans. Famous footage exists of orca pods hunting down large whale mother and calves. With their cooperation, they can attack animals much larger than themselves. This is what affirms the orca as the top predator in the ocean. The sailors that observed the mammal eating orcas coined the original name “whale killers”, which later got reversed to killer whales.

Threats

Some populations of orcas are doing well, however in some parts of the world, the populations are at serious risk of disappearing. For example, the West Coast Community around the UK, only have 8 members left. Lulu was a member of the West Coast Community, and was found dead in 2016 with shocking levels of PCB pollution. The levels of pollution found in Lulu possibly reflect the levels in the remaining pod members, and may explain why the pod has not produced a calf in the 28 years that it has been studied.

The Southern Residents are also a well-known population that is not faring well. This is likely due to their choice of prey, the Chinook salmon, which is heavily depleted. Recent observations of some of the members show them to be very thin and in ill health. With their prey source in decline, the orcas are struggling.

Plastic pollution is a global problem for all ocean creatures. In January 2020, a juvenile male orca was found washed up in England with a large fragment of plastic in its stomach. A baby orca was found playing with a plastic bag in the Pacific Northwest in 2013. Many cetacean species get entangled in fishing gear, and it can almost be certain that orcas have experienced this too.

Though less of a threat now, orcas have been exposed to commercial hunting. The earliest known records were in the 18^th century in Japan. They have been less targeted than the larger whales, but have still been victims of whaling. Before orcas were taken into captivity, they were largely feared and would be killed out of spite.

In not necessarily a lethal manner, orca populations have been under threat of being captured for captivity. The North Pacific population had been severely targeted and then the Icelandic populations. For several decades, orcas breathed a sigh of relief as it seemed no more wild orcas were being taken, but then captures resumed in 2012 in Russia. Orcas experience stress of their family units being broken up, and some unintentionally drown in the fishing nets.

A final ocean threat that orcas experience are noise and vessel disturbance. Whale watching companies may unintentionally harass orcas, as people wish to see them in the wild. Underwater nose from shipping, drilling and other human activities may be of significant disturbance to the orcas.