Photo: NOAA
Aerial image of Granny J2 (right) and a juvenile orca, J45, chasing a salmon in September 2016. Ultimately J2 captured the salmon and presented it to J45.
Being a grandparent himself, my husband recently took note of some research on grandmothers in the animal kingdom and judged it blogworthy. This version of the story appeared online at King5News.
Michael Crowe reports, “A team of researchers have found having a young orca’s grandmother around improves survival of the offspring. A study published last week in the Proceedings of the National Academy of Sciences tests the ‘grandmother effect’ in Southern and Northern Resident killer whales off Washington state and British Columbia. …
“The study used decades of photo census records of the two populations to study survival of individual whales and connected family groups through observation. And they found if a grandmother whale died, it reduced the survival of her ‘grandwhales’ in the two years following her death.
“ ‘The statistics showed they were healthier and lived longer when they had a thriving grandmother,’ said Howard Garrett, co-founder of the Orca Network.
“Dr. Deborah Giles, a killer whale researcher at the University of Washington Center for Conservation Biology, said the study confirmed decades of observations.
“ ‘They’re incredibly socially bonded animals,’ Giles said. She said it’s a fascinating relationship, because whales can live decades after they cease reproducing – killer whales have evolved one of the longest post-reproductive spans outside humans.
“She recalled an aerial photo of J2 (also known as ‘Granny’) from 2016 sharing fish with J45 – her apparent great-grandson. J45’s mother had recently died, and he was not yet old enough to thrive without support. Though J2 was thin and towards the end of her life, she helped the younger relation.
‘It sticks out to me, because this is an animal in here late 80s, maybe old as early hundreds,’ said Giles. ‘She’s clearly trying to keep that fish in the pathway of her relative so he’ll eat it. …
” ‘She could have eaten that fish in one bite, but she chose to corral it toward him so he’d grab it.’
“The study also notes the importance of grandmother whales in lean salmon years when the female leaders serve as ‘repositories for ecological knowledge.’ …
“ ‘The grandmothers have that long perspective, the multi-decade look at where the salmon have been, the nooks and crannies,’ said Garrett. ‘… So they’re constantly in that role of guide, mentor, teacher. They share not only their food, but their traditions, their ways.’ …
“There are 73 Southern Resident whales we know of, Giles said, and of that, there are just four grandmothers remaining – one in J pod, one in K pod, and two in L pod. She worries that these grandmothers will only become more important to the endangered Southern Resident killer whales’ survival. …
“Garrett also hopes deeper knowledge of the whales’ behaviors will encourage people to help protect them.
“ ‘I think the study helps people learn more detail, more higher resolution if you will, of how they live and who they are,’ he said. ‘They really are individuals with their own identities, their own roles, their own place in their societies and in their families. And the more we get to know them in that kind of intricate detail, the more we feel close to them, and want to help them in any way we possibly can.’ ”
More here.
Photo: Shutterstock
Another name for the orca is killer whale.
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