Killer Whale, Orcinus orca

Killer Whale, Orcinus orca. Photograph taken in coastal waters off Danzante Island, Loreto, July 2018. Photography and identification courtesy of Ricky Trevor, Loreto, Baja California Sur.

Killer Whale, Orcinus orca. Photograph taken in coastal waters of Gonzaga Bay, Baja California, June 2016. Photography and identification courtesy of Chris Wheaton, Fullerton, California.

Phylogeny:  The Killer Whale, Orcinus orca (Linnaeus, 1758), is the largest member of the Delphinidae Family of Oceanic Dolphins.  The genus Orcina is one of eighteen genera in this family, and this species is the only species in the genus. Killer Whales are also called Orcas. In Mexico they are known as asesina ballena. There are no accepted subspecies of Killer Whales. They are perhaps the most easily recognized, and most studied, of the toothed whales. Killer Whales received their name from early whalers who saw them attacking other species of whales, and called them Whale Killers. The scientific name appears to be a play on words: Orcinus means belonging to Orcus, a Roman god of the underworld; orca means barrel or chest, referring to the whale’s girth.

Morphology:  Killer Whales are very robust with conical heads and an indistinguishable beak. The sexes are dimorphic with males and females differing in size, relative fin size, and dorsal fin shape. The male’s dorsal fin is very erect with a straight trailing edge that reaches 1.8 m (6 feet 0 inches) in height. The female’s dorsal fin is falcate (curved) and about half the height of the males. Killer Whale flippers are much more rounded than those of other dolphins, with the male’s flippers significantly larger in proportion to the body than the female’s. The flukes of the male curve downward compared to the female. The Killer Whale’s black and white coloration is striking in its contrast. The fins and most of the body are black. They have a small oval patch of white behind the eye and the underside of the jaw, the ventral surface, the underside of the flukes, and curved patches, posterior to the dorsal fin, extending half way up the body from the ventral surface, are white. There is a gray to white saddle behind the dorsal fin, which varies in shape. Male Killer Whales reach 9.0 m (30 feet) in length and 5,600 kg (12,000 pounds) in weight. Females reach 7.9 m (26 feet) in length and 3,800 kg (8,400 pounds) in weight.

Habitat and Distribution:  Killer Whales are considered the most widely distributed cetacean species; some argue that, next to humans, they are the most widely distributed of all mammals. They are found in tropical, temperate, and polar seas. Most stay relatively close to shore but some venture far out to sea. They are accomplished divers, reaching depths of up to 2,650 m (8,700 feet). They are sometimes found in freshwater rivers, in search of fish schools. One was found 106 miles up the Columbia River in Oregon. Killer Whales are found along both coasts of Mexico, though they are much less common on the East coast, with most sightings around the tip of the Yucatán Peninsula. They are relatively common along the entire Pacific coast, including throughout the Gulf of California.

Diet:  While there is only one species of Killer Whale, there are several specific ecotypes within the species that vary widely in behavior and prey. This may eventually lead to the species being separated into two or more new species. Some Killer Whales are resident populations that feed primarily on fish, such as salmon. Others are transient and feed on marine mammals, including other dolphins, whale calves, and the tongues of large whales. Some are more opportunistic and eat large game fish, octopus, penguins, polar bears, sea turtles, sharks, squid, and other land mammals that venture in to the sea. Much of the hunting appears coordinated, like a wolf pack. Killer Whales appear to be the apex predator in the ocean.

Predators: Adult Killer Whales are the apex predator of the ocean and have no predators. There are reports of white sharks attacking lone calves and sick or injured adults.

Reproduction: Killer Whales reproduce through sexual reproduction, with internal fertilization. Females reach sexual maturity when they are between ten and thirteen years old. They are typically pregnant for 15 to 18 months and give birth to a single calf. Newborn calves are about 2.4 m (eight feet) long and weigh around 182 kg (400 pounds). Calves nurse  for at least a year and remain in close association with their mother for the first two years of their life. During this time, Killer Whale mothers are protective of their young, and other females often help care for them. Mothers teach their calves to hunt and include them in their pod’s social network. Mothers give birth about every five years. Female Killer Whales go through menopause at around age forty. Males live an average of 30 years in the wild, but are known to reach 60. Females average about 50 years, but are known to reach 90.

Ecosystem Interactions:  Killer Whales host various internal parasites, including; cestodes, nematodes, trematodes, and lungworm. They also host Killer Whale Lice and occasionally, barnacles. They play a significant role in the foodweb, both locally and globally.

Human Interactions: Killer Whales are protected by international law. They are no longer captured for display in oceanariums. There are an estimated 50,000 Killer Whales alive in the world today. For the purpose of monitoring population levels, the population is divided into geographic regions. Some of the populations are considered Endangered, others are considered to be of Least Concern. In Mexico, Killer Whales are considered to be a Special Protected Species by the Norma Official Mexicana. The IUCN Red List considers the general Killer Whale population status to be Data Deficient requiring further studies and evaluations. Killer Whales still face threats from entanglement in fishing gear, noise pollution, bioaccumulation of chemical pollutants, and loss of food stocks. While it is widely believed that there has never been an attack on a human being, in the wild, by a Killer Whale, that is not true. A surfer was injured in a Killer Whale attack in 1972 near San Francisco, CA. They have also been documented attacking, and sinking, small boats. While attacks are extremely rare, Killer Whales should be treated with the same caution that you would treat any wild predator.

Note:   I have had two personal encounters with Orcas.  The first was in 2007 when a pod buzzed the commercial beach (Point Lobo) in Todos Santos, Baja California that created quite a stir amongst the commercial fishermen. The second was in 2009 and I was in Mexican panga sportsfishing and a small Orca fell in love with our motor, approaching and bumping the motor at least a half dozen times. It would not leave us alone and we had to vacate the location.

Synonyms: Delphinus duhameli, Delphinus gladiator, Delphinus grampus, Delphinus orca, Delphinus orca ensidoratus, Delphinus serra, Delphinus victorini, Grampus orca, Grampus rectipinna, Grampus vectipinna, Ophysia pacifica, Orca africana, Orca antarctica, Orca ater, Orca ater fusca, Orca atra, Orca capensis, Orca eschrichtii, Orca glacialis, Orca gladiator, Orca gladiator arcticus, Orca gladiator australis, Orca gladiator europaeus, Orca gladiator tasmaniensis, Orca latirostris, Orca megellanica, Orca minor, Orca orca, Orca orca megallanicus, Orca pacifica, Orca rectipinna, Orca schlegelii, Orca stenorhyncha, Orca tasmanica,  Orcinus glacialis, Orcinus nanus, Orcinus orca capensis, Orcinus orca eschrichti, Orcinus orca megallanicus, and Physeter microps.