We’re including Orcas – otherwise known as Killer Whales – in our “Species in Focus” since they are increasingly including sharks in their diet. The orca is one of the most powerful apex predators. Orcas are different from sharks: they are mammals, not fish. This means that they breathe air and nurse their young through mammary glands. Orcas are the largest species in the dolphin family and are easily recognizable with their distinct black and white coloration. These smart, social creatures inhabit all of the world’s oceans, living in groups called pods, and giving live birth to orca young called calves. In these pods they communicate and hunt through coordination and echolocation (the location of objects that reflect sound).
New research about orcas is very much connected to sharks. They are documented feeding on many types of sharks, and now there is new evidence to show that they feed on the largest fish on Earth, the whale shark!
Orcas At-A-Glance
Scientific Name – Orcinus orca
What size do orcas get? Approximately 23-32 feet (7-9.75 meters) and up to 6 tons in weight
Where do orcas live? All oceans on Earth, yet are most abundant in temperate waters. They are studied in the North Pacific.
What do orcas eat? Incredibly diverse diet that varies depending on the location inhabited by the orcas. These marine mammals may eat fish, other marine mammals, squid, birds, turtles, sharks and rays.
How do orcas reproduce? Females reach sexual maturity between the age of 7 and 16 while males reach maturity between the age of 10 and 17, typically not reproducing until the age of 21. There is no specific breeding season. Orcas are viviparous meaning they give live birth to calves. The female is typically pregnant for 15 to 18 months before they give birth to a single calf. They typically give birth to one calf every five years. Mother killer whales are incredibly protective of their young, exhibiting extensive parental care. The calves nurse for one year after their birth and they remain close to their mothers for two years after birth when they learn social and hunting behaviors of the pod. The female then goes through menopause at approximately age 40.
How long do killer whales live? 30-90 years (longer end of spectrum in the wild)
What is the IUCN conservation status? Orcas currently possess an IUCN listing of “Data Deficient” meaning that there is not sufficient data to determine the true population status.
Do any laws exist protecting orcas? Killer whales are protected in multiple countries such as Mexico, the United States, and Canada. In the United States, Orcas are protected under the Marine Mammal Protection Act of 1972 making it illegal to hunt marine mammals. Other organizations such as NOAA and their partners are conducting continued research to ensure conservation practices. Unfortunately they are still vulnerable to human induced loss of food or habitat globally as well as other threats such as entanglement in nets and pollution.
Frequently Asked Questions about Orcas:
Why are orcas called a killer whale? Orcas are known to prey on other marine mammals, giving them the title of a whale killer. This name was popular amongst ancient sailors and fishermen who observed this behavior and the name stuck, shifting overtime to killer whale.
Are orcas friendly to humans? Killer whales ademonstrate inquisitive behaviors towards humans and other animals in the wild, yet like any apex predator, and any animal in general, they must be treated with respect and caution.
Are there only 73 orcas left? How many are left in the world in 2024? NOAA estimates that there are approximately 50,000 orcas globally.
What eats orcas? They have no known natural predators. Humans and pollution are their largest threat.
Are orcas friendly to dolphins? Killer whales are known to play and interact with dolphins, being especially gentle when they recognize a smaller animal. Yet, they are also known to prey upon dolphins as well.
Bet you didn’t know….
- The orca species can be separated into multiple ecotypes, populations or subspecies adapted to a specific environment. In the north eastern Pacific ocean there are three confirmed ecotypes, the Resident which eats bony fish, the Offshore which eats cartilaginous fish, and the Transient which eats marine mammals. A new ecotype has recently been proposed for the Eastern Tropical Pacific region, “generalists” because they possess a more generalist diet.
- Killer whales teach their young the unique hunting techniques and social behaviors of the pod. These behaviors are passed from generation to generation of orcas.
- Killer whales are one of the only mammals that go through menopause (just like humans). Recent studies show that the “grandmother” does so to be available to raise and teach the calves and/or juveniles in the family instead of continuing to have her own offspring.
- They are such good predators that they can successfully prey on whale sharks, the largest fish on Earth.
- Killer whales are one of the fastest marine mammals reaching burst speeds of up to 35 miles per hour (55 kilometers per hour).
Science In The Spotlight
A new study researching orca predation has revealed where the mammals may get their next meal – spoiler alert it’s not good news for whale sharks!
Check out what this paper reveals about the hunting techniques of orcas.
This month you can also read a Q&A with marine biologist and one of the study authors, Erick Higuera.
After Bites Orca Quiz
Take the orca trivia quiz and test your new found knowledge.
Written by Anna Keefer, Environmental Sciences and Environmental Thought and Practice Double Major at the University of Virginia and Shark Angels Intern