Two older female orcas die, affecting L podJune 20th, 2013 by cdunagan
Two of the oldest female orcas in L pod have been reported missing and presumed dead by the Center for Whale Research, which will release its annual census count of the three local orca pods on July 1.
The overall population of the Southern Resident killer whales, which frequent Puget Sound, has dropped to 82 animals, continuing the general decline since the three pods totaled 89 whales in 2005. The current count is barely above the low point of 79 animals in 2001.
One of the missing females is L-2 or “Grace,” estimated to be 53 years old. Since she has no surviving female children, her long line of ancestry will die out with the eventual death of her son, L-88 (“Wave Walker”).
Killer whales, both male and female, generally stay with their mothers for life. In a healthy orca population, each matriline is headed by an older female, along with all her surviving children and grandchildren.
Since L-2 was beyond reproductive age, her matriline reached a dead end with the death of her daughter, L-67 (“Splash”) and L-67’s daughter L-101, (“Aurora”), both in 2008. There were no other females to carry on the line.
L-67’s other offspring was L-98 (“Luna”), who became separated from his family and lived for several years in Nootka Sound along the west coast of Vancouver Island. Movies have been made about Luna and the unsuccessful effort to reunite him with his family. Luna was killed by a tugboat in 2006.
Ken Balcomb, director of the Center for Whale Research, said it has been evident for some time that L-2’s matriline would die out. At least three or four other matrilines in L pod are in a similar condition, which leads Balcomb to believe that the population is likely to continue its decline before it turns around, if that’s possible.
L-2, last seen in December, is survived by a son, L-88 (“Wave Walker”), whose fate is yet to be determined. The 20-year-old was very close to his mother.
“When the mother dies, there is a high probability that the male son will not survive,” Ken told me. “It seems a male needs an older female. I think there is some sort of role in the social structure. Maybe the female keeps track of relationships and who is appropriate for mating. It is all speculation, but L-2 was a container of wisdom.”
Sometimes a male will survive if he is accepted into another group with older females. L-87 (“Onyx”), a 21-year-old male, lost his mother. He began traveling with K pod and later with J pod, which may have kept him going. His sister, L-22 (“Spirit”) and her two sons remain in L pod.
But the number of reproductive females in each pod is really what establishes hope for the future, Ken said.
“That’s why L-112 is such a tragedy,” he noted.
L-112, a 3-year-old female named “Victoria” or “Sooke,” was found dead on Long Beach in February of 2012. An investigation listed the cause as “blunt-force trauma.” The cause of trauma may never be known, according to the latest reports. (It is probably time for me to update the evidence that is available.)
I guess I haven’t said anything about the other female reported missing. She is L-26 (“Baba”), last seen in March and reported as looking emaciated by researchers with the Northwest Fisheries Science Center. L-26, estimated to be 57 years old, has a 20-year-old daughter, L-90 (“Ballena”). We’ll see how L-90 fares over the next few years.
As in all populations, including our own, individuals get old and die. Ken noted that he has been keeping tabs on these whales for nearly 40 years, which means he has grown older with them.
“When we began this study, we didn’t think they would live this long,” Ken told me. “It is sad that lives have ended, but nature marches on.”