The Orca Network told KIRO that Granny is said to be around 105 years old, but there is a 12-year margin around her age meaning she could be as young as 93.
The average lifespan of a wild orca is between 60 and 80 years.
The Southern Residents -- despite being listed under the U.S. Endangered Species Act -- have some extraordinary longevity stories, including the female K7, or Lummi, who died in 2008 at the age of 98, according to the Pacific Whale Watch Association (PWWA).
Another Southern Resident female, L25, or Ocean Sun, is thought to be 85 years old.
PWWA Director Michael Harris told the SeattlePi blog how researchers estimate ages of orcas.
“Wild orca researchers use an extrapolation scheme to estimate ages of orcas. It’s a well-accepted technique used by both U.S. and Canadian scientists, based on the fact that offspring stay close to their mothers all their lives.”