In reading The Killer Whale Who Changed the World by Mark Leiren-Young, I learned that there are only three animal species where the female continues to live long past her reproductive years. They are: Short-finned Pilot Whales, Orcas, and humans. Orca females are thought to live as long as 100 years. There seems to be an evolutionary advantage to this. These matriarchs have the knowledge of where to find food, and their sons who stay with them throughout their lives often die within a year of their mother’s death. After a long absence, the Southern Resident Orcas have returned to Howe Sound/Atl’kitsem. They are considered an endangered species with only 76 remaining in the Pacific Northwest.