The orca (Orcinus orca) — commonly called the killer whale — is the ocean’s apex predator and one of the most intelligent, socially complex animals on Earth. In Alaska waters, orcas are a defining presence, ranging from Southeast Alaska fjords to the Bering Sea in search of prey.
Ecotypes: Not One Species
Alaska’s orcas comprise distinct ecological populations, or “ecotypes,” with remarkably different cultures, behaviors, and diets:
- Resident orcas: Fish specialists — primarily salmon. Live in matrilineal family groups with complex vocal dialects passed between generations. Highly social, spend their entire lives with their birth family.
- Transient (Bigg’s) orcas: Marine mammal specialists — hunting seals, sea lions, porpoises, and even gray whale calves. Quieter, stealthier hunters operating in smaller groups.
- Offshore orcas: Deep-water fish specialists, less studied, found offshore in Alaska’s continental shelf waters.
These ecotypes rarely interbreed, have distinct calls, and have evolved separately for thousands of years — leading some researchers to classify them as separate species.
Intelligence and Culture
Orcas demonstrate some of the most sophisticated cognitive and social behaviors in the animal kingdom:
- Cultural transmission: Each family group has unique calls, hunting strategies, and traditions passed down through generations — a hallmark of culture.
- Teaching: Mothers teach calves complex hunting techniques, including intentional beaching to catch pinnipeds.
- Grief: Extended responses to calf deaths have been documented in multiple populations.
- Play and tool use: Documented play behavior and creative problem-solving.
Alaska Ecosystem Role
Orcas play a complex role in Alaska’s marine ecosystem. Transient orcas are believed to have triggered “trophic cascades” — declines in sea otter populations in the Western Aleutians drove urchin explosions and kelp forest loss — a chain of ecological effects traced back to changes in orca prey availability decades earlier.
Science at ASLC
The Alaska SeaLife Center’s research contributes to understanding orca-ecosystem interactions, including bioacoustics studies and research on how prey availability changes driven by climate and fisheries affect orca behavior and distribution in Alaska waters.