Did you know orcas are led by their grandmothers? Orcas are one of only five species known to go through menopause, and their post-reproductive females become leaders of the pod, guiding hunts and passing down generations of survival knowledge to their families. Meet the ocean’s most powerful matriarchs.

Despite their name, “killer whales”, orcas are actually the largest member of the dolphin family, reaching up to ~ 32 feet long. They’re found in every ocean on Earth, second only to humans in range, and are easily recognized by their black and white bodies and tall dorsal fins.

Orcas live in small pods, ranging from several individuals to up to around 50, with pod sizes varying based on ecotype. Each pod belongs to an ecotype, which are sub-sections of the population that differ from each other in diet, appearance, genetics, behavior, and hunting strategies. In the North Pacific, where there have been extensive studies on these ecotypes, there are three identified ecotypes identified; resident, transient, and offshore orcas. As this ecotype framework is well understood for orcas in the North Pacific, it is unclear if similar ecotype structures applies to orcas globally, with further research needed. Orcas have a matriarchal hierarchy made up of mothers, grandmothers, juveniles, calves, and mature males, and orcas typically stay with their mother’s pod for most of their lives.

In 1993, orcas swam their way into the hearts of the public with the movie Free Willy, the story of friendship between a young boy and a captive orca.

More recently, headlines have taken a different turn. Since 2020, groups of orcas have been increasingly approaching and interacting with boats along the Iberian Peninsula. Scientists suspect that these interactions are a result of these boats triggering a past encounter such as a collision with a similar boat, pressures such as boat disturbance impacting orcas, or simply out of curiosity from these animals.

Orca mothers keep the pods connected through their lineage and carry one of the longest gestational periods of any marine mammal – about 15 to 18 months. Mothers nurse their calves for about a year before they learn to hunt alongside their mother and their pod. Mothers typically have a calf every 6 to 10 years, averaging about 4 to 6 calves over a lifetime, often creating generational overlap where a mother and her daughter may be raising their calves at the same time.

Orcas are one of only five confirmed species to go through menopause. Freed from raising calves of their own, post-reproductive grandmother orcas take on a leadership role, passing down hunting knowledge and ecological understanding to their relatives. This is known as the “grandmother effect”, and research shows it directly increases the survival of grand-offspring, playing a key role in the societal structure and survival of the pod. That boost matters for a species that invests heavily in raising young and sees high mortality in the earliest years of life, making these grandmothers true matriarchs of the ocean.

Pods pass down wealth of survival, hunting, and parenting knowledge across generations. Orcas are generalists with diets that can include fish, seals, sea lions, sharks, salmon, squid, octopus, sea birds, sea otters, river otters, sea turtles, and other whales and dolphins; specific orca ecotypes can be more specialized. For example, in the North Pacific, resident orcas mostly focus on salmon for their prey, while offshore orcas eat other types of fish and sharks. When it comes to the North Pacific transient orca ecotype, they eat a wide variety of prey including seals, dolphins, and even other whales!

Hunting strategies vary by pod ecotypes. Techniques include pods coordinating waves to knock prey such as seals off chunks of sea ice, as well as intentionally beaching themselves to capture seals and sea lions. Pods also use their own dialects, unique to each pod, to assist with their hunting strategies and stay together when navigating the ocean. These dialects help pods communicate and execute the herding and preying on of larger fish and whales. These unique dialects are passed down from generation to generation within a pod and have been shown to stay the same for up to six generations.

Unfortunately, these animals are at risk. While there is not enough data to assess orcas as a whole species to determine their status according to the IUCN red list, some ecotypes found in U.S. waters that have been evaluated, are listed as endangered under the Endangered Species Act.

Despite having no natural predators, orcas face serious threats from human activity. Historically, whalers targeted them across the Atlantic, Pacific, and Antarctic regions, and fishers have shot them, perceiving orcas as their competition. Today, overfishing and habitat loss are depleting their prey, while climate change threatens the sea ice that prey species depend on. Conservation efforts now focus on protecting orca habitats and supporting fish population recovery.

Orcas are incredible animals, with highly organized family-oriented societies and one of the widest ranges of any species on Earth. But they need our help. Orcas depend on thriving oceans to survive.

Add your name to protect the Endangered Species Act or visit the Oceana store to symbolically adopt an orca. Learn more about this fascinating species by visiting Oceana’s Marine Life Encyclopedia.