Orca

The orca (Orcinus orca), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. It is easily recognized by its mostly black back, white belly, and white patches around the eyes. Orcas live in many parts of the world's oceans, from the cold Arctic to the Antarctic regions, though they are most often seen in cooler coastal waters.

As apex predators, orcas have a varied diet and often hunt in groups. Different groups may prefer different foods, such as fish, sharks, rays, or even other marine mammals like seals and dolphins, and whales. They are very social animals, living in family groups called pods, and they use complex vocal sounds and hunting strategies that are passed down through generations.

Orcas have fascinated people for a long time. Indigenous cultures have respected them, while in the past, some Western cultures feared them. In the 1960s, orcas began appearing in marine parks, where they were trained to perform tricks. Though this brought more attention to the species, it also raised concerns about their welfare. Orcas are generally not dangerous to humans in the wild, but there have been incidents in captivity where they have harmed their handlers.

Naming

Orcas are often called "killer whales" because long ago, sailors saw them hunting larger whales. Today, many people prefer the name "orca." The name comes from a Latin word meaning "a large-bellied pot," and it was used by Ancient Romans to describe these animals.

Sometimes orcas are also called "blackfish," a name shared with a few other whale-like animals. Another old name for them was "grampus," but this word is rarely used now. It’s important not to confuse this with a different kind of dolphin called Risso's dolphin.

Taxonomy

The orca, also known as the killer whale, is the only living species in its genus, Orcinus. It was first described by the famous scientist Carl Linnaeus in 1758. Orcas belong to the oceanic dolphin family, which has existed for about 11 million years.

There are several types of orcas, and scientists are still learning about how they are related. Some orcas mainly eat fish, while others hunt marine mammals. Recent studies suggest that some groups of orcas might be distinct species, but more research is needed to confirm this.

Characteristics

Orcas, also known as killer whales, are the largest members of the dolphin family. Males are usually between 6 to 8 metres long, while females are a bit smaller, ranging from 5 to 7 metres. Both male and female orcas have distinctive black and white colouring, making them easy to recognize. Males have larger dorsal fins and pectoral fins compared to females.

Orcas have excellent eyesight, hearing, and a special ability called echolocation, which helps them find food underwater by making clicks and listening for echoes. They also have thick blubber to keep warm in cold water. Each orca can be identified by the unique shape of its dorsal fin and the pattern of its saddle patch, which helps scientists study their lives and social groups.

Range and habitat

Orcas live in all oceans and most seas. They are found in many places, especially in cooler areas near coasts. Some well-studied places include the coasts of Iceland, Norway, the Valdés Peninsula in Argentina, the Crozet Islands, New Zealand, and parts of the west coast of North America, from California to Alaska. They are most common near the Norwegian coast, the Aleutian Islands, the Gulf of Alaska, and near Antarctica.

In the Antarctic, orcas can be found near the edge of the ice and sometimes even go deeper into the ice. They visit Arctic waters but only during certain times of the year. Sometimes, they even swim far up rivers, like the Columbia River in the United States. Each summer, the same orcas appear off the coasts of British Columbia and Washington, but where they go the rest of the year is still a mystery.

Feeding

Orcas are apex predators, which means they have no natural predators of their own. They are often called "wolves of the sea" because they hunt together in groups, much like wolves do. These clever animals eat many different kinds of food, including fish, squid, mammals, birds, and even sea turtles. Different groups of orcas might focus on certain foods depending on where they live.

Some orcas mainly eat fish, like salmon and herring. In places like Norway, they follow herring during their migration. They have special ways to catch fish, such as working together to herd herring into a tight group and then stunning them with their tails before eating. Other orcas eat marine mammals such as dolphins, porpoises, seals, and even larger whales like sperm whales and grey whales. They work together to chase and catch these animals, sometimes even working with waves to wash seals into the water. Orcas also eat birds, though they often do not eat them and just leave them.

Behaviour

Orcas, also known as killer whales, spend their days foraging for food, traveling, resting, and socializing with each other. They often jump out of the water or slap their tails on the surface, which can be for communication, play, or to remove parasites. Orcas can swim very fast, reaching speeds of up to 15.5 m/s (56 km/h; 35 mph). They sometimes swim close to porpoises and dolphins.

Orcas live in complex social groups, similar to elephants and higher primates. These groups are based on family ties, with the oldest female, called a matriarch, leading. Orcas often stay with their mothers their whole lives. These family groups sometimes come together in larger groups called pods. Some orcas, called transients, leave their family groups more often.

Orcas use sounds like clicks, whistles, and calls to navigate, find food, and talk to each other. Each family group has its own set of calls, which helps them stay connected. Orcas are very intelligent and can learn new skills. They have been seen using tools and solving problems, showing their cleverness.

Life cycle

Female orcas begin to mature around the age of 10–13 and can often breed until age 40. They are among the few animals that undergo menopause and live for decades after they have finished breeding. The lifespans of wild females average 50 to 80 years.

Males mate with females from other pods, which prevents inbreeding. Males sexually mature at the age of 15, but do not typically reproduce until age 21. Males can often reproduce until they are 59 years old. Wild males live around 29 to 30 years on average, with a maximum of about 50 to 60 years.

Conservation

In 2008, the IUCN changed its assessment of the orca's conservation status to data deficient, suggesting some orca types might be endangered species. Major threats to orcas include depletion of prey species, pollution, large-scale oil spills, and habitat disturbance from noise and boat conflicts.

Orcas are at risk from bioaccumulation of toxins like Polychlorinated biphenyls (PCBs). In the Pacific Northwest, wild salmon, a key food source, have declined, affecting orca populations. The southern resident community in the Puget Sound region faces serious threats due to low salmon numbers. Underwater noise from human activities also disturbs orcas, affecting their behavior and habitat.

Relationship with humans

Indigenous cultures

The Indigenous peoples of the Pacific Northwest Coast have long featured orcas in their art, history, spirituality, and religion. For example, the Haida regarded orcas as powerful ocean animals, with stories of them living in underwater houses and towns. The Kwakwaka'wakw saw orcas as rulers of the undersea world. Many coastal groups view orcas as important spiritual beings and family relatives.

Other cultures also hold deep respect for orcas. The Maritime Archaic people of Newfoundland created stone carvings of orcas thousands of years ago. The Siberian Yupik people tell stories of orcas appearing as wolves and helping hunters. The Ainu people of Hokkaido and nearby islands honored orcas in their traditions.

Attacks by wild orcas on humans and animals

In Western cultures, orcas were once seen as dangerous predators. However, there are very few confirmed attacks on humans by wild orcas, and none have been fatal. Examples include orcas trying to move ice floes with a dog team on them, a surfer being bitten (but escaping), and a boy being bumped while playing in water.

Orca attacks on sailboats and small vessels

Since around 2020, some orca pods have begun interacting with sailing vessels near the southern tip of Europe. These interactions have sometimes damaged or sunk boats, with at least 15 reports in 2020 alone. Experts debate whether this behavior is playful, defensive, or related to past events.

Modern Western attitudes

Views on orcas changed greatly in the 1960s and 1970s. The capture and study of a whale named Moby Doll showed that orcas could be calm and friendly. Research revealed their complex social lives and strong family bonds. Public interest grew so much that orcas became cultural icons, leading to protections and efforts to return captured orcas to the wild.

Whaling

Orcas were not often hunted until larger whale populations declined. Between 1954 and 1997, countries like Japan and Norway hunted thousands of orcas. International rules now limit hunting, though small amounts are still allowed in places like Indonesia and Greenland.

Whale watching

Watching orcas from boats is very popular but can bother the whales. Many boats follow the same group of orcas for hours, creating air pollution that may harm their health. Rules now require boats to stay farther away from the whales.

Captivity

Orcas are often kept in aquariums and aquatic theme parks because of their intelligence and size. However, many believe this is unfair to the whales, as their lives in captivity are much shorter and more stressful than in the wild. Some parks have stopped breeding orcas and performing shows, but others continue these practices.