About Orcas
Killer whales are the largest members of the dolphin family.
Physical Features:
Killer whales have a striking black coloring with grayish-white saddle patch and white belly. Much like their dolphin cousins, they have a conical-shaped head with a small beak and 10-13 conical teeth on both the upper and lower jaw. They have paddle-shaped pectoral fins, and a distinct dorsal fin (curved in females and immature males; straight and up to about six feet tall in males). The male orca's dorsal fin reaches its full height at age 15-25 years.
Identification:
Unique markings and dorsal fin shape allow Center for Whale Research staff to identify individual orcas. The whale's dorsal fin varies in shape and size, often with distinctive nicks and scars. The saddle patch also differs from whale to whale in shape, size, color, and scarring. In the case of the Southern Resident orcas, individual identification allows CWR staff to maintain a precise census of the population; accounting for every whale on an annual basis.
Taxonomy:
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Suborder: Odontoceti
Superfamily: Delphinoidea
Family: Delphinidae
Orcas are in the suborder Odontoceti, or toothed whales; referred to as Odontocetes. Odontocetes differ from other cetaceans (whales and dolphins) in that they have teeth instead of baleen (such as is the case with humpbacks and grey whales). Orcas (killer whales) are one of 35 species in the oceanic dolphin family, Delphinidae. Although they are referred to as whales, orcas are in fact the largest member of the dolphin family and are physiologically similar to dolphins. Other alike species include Pygmy killer whales, False killer whales, and Pilot whales.
Migration:
Although orcas tend to aggregate in cold water, they live in all the world's oceans, from the Antarctic to the tropics. Unlike other whales that follow predictable seasonal migration patterns, orcas tend to go wherever their food source is, making their movement patterns much less predictable. Salmon or herring migrations seasonally influence the distributions of some orcas. Other orca ecotypes (e.g., Transients) move in response to the location of their marine mammal prey, such as seals and sea lions.
Natural History:
The life cycle of orcas is similar to that of humans. Female orcas become mature around age 15. Among the Southern Resident orcas, the youngest known mother is J37. Mating and calving take place year round. Gestation varies from 15 to 18 months, with the average birthing rate about once every five years. A typical female will have on average 3-5 calves during her lifetime. Females are reproductive until about age 40. Calf mortality is high during the first year of life with approximately 37%–50% of all calves dying. Calves will typically nurse until age two but will begin to eat some solid food around age one.
The average lifespan of female orcas in the wild is 50 years, with several individuals living as long as 80–100 years (estimated).
Male orcas become fully sexually mature at age 25. Between ages 12 and 15, their dorsal fin begins to grow taller and straighter, indicating the onset of sexual maturity. Male orcas typically don’t mate until after the age of 20. Males in the wild live 29 years on average, to a maximum of 50–60 years. J1, who died in 2010, was estimated to be 59 years old.
A captive orca's lifespan is typically much shorter, often by 25 years or more.
Status: Endangered.
Designated endangered in Canada in 2001;
United States in 2005.
Name:
The Latin name is Orcinus orca. Common names are orca or killer whale, while other names include blackfish, grampus, and killer. Most English-speaking scientists use the name killer whale, although orca is increasingly used, in particular by the general public. The name killer whale originated from the Spanish whaler’s term “whale killer,” based on their observations of orcas hunting other types of whales. In ancient Roman mythology, the genus name, Orcinus, means "of the kingdom of the dead," or belonging to “Orcus," ruler of the dead. The species name in Latin, orca, literally means "the shape of a barrel or cask," likely due to the orca's body shape. This term is thought to be borrowed from the Greek word that was commonly used to refer to whales.
Size & Weight:
Orcas are the largest members of the dolphin family. Males are larger than females, and adult males are distinguishable (sexually dimorphic) by the increased size of their dorsal fin at sexual maturity
(about 25 years).
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Male orcas usually grow to an average of 20-26 feet (6-8 m) and weigh an average of 8,000-12,000 lb (3,600-5,400 kg)
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Females evolve to an average of 16-23 feet (5-7 m) and weigh between 3,000–6,000 lb (1,300-2,700 kg)
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Calves weigh about 400 lb at birth (180 kg) and are between 7-8 feet long (2-3 m).
The largest male orca on record measured 32 feet (9.8 m) and weighed over 20,000 lb (9,000 kg), while the largest female measured 28 feet (8.5 m) and weighed 15,000 lb (6800 kg).
The grayish-white saddle patch varies from individual to individual in shape, size, color, and scarring.
Photo above: J2/Granny (left), who died in 2016, was the oldest known Southern Resident killer whale. Her estimated age was 106 years. J1/Ruffles (right) was determined to be the oldest male in the SRKW community: 59 years old when he died in 2010.
