Orca Grannies Increase The Survival Rate Of Their Grandchildren

By :
PA

Grandma, Granny, Nan, Nanna – whatever you call yours, we all love our grandmothers. 

Advertisements

From the start of our lives, our grandmas often play a vital role: whether that’s by giving us our annual pair of Christmas socks and backing our corner when we’re in trouble, to fuelling our unhealthy addiction to sweets and looking after us while our parents were at work.

Well, it turns out human grandmothers aren’t the only ones who play a huge part in their grandchildren’s lives – Orca whale grandmas do too for their grand-orca-babies (AKA calves to those whale boffins out there).

Advertisements
PA

A new study published by the Proceedings of the National Academy of Sciences (PNAS) found Orcas are the only species that rely on grandmothers to watch the kids.

Advertising

In the study it said:

We find evidence for the grandmother effect in killer whales: the death of a grandmother reduces the survival of her male and female grandoffspring in the 2 y following her death.

Grandoffspring whose maternal grandmother died within the last 2 y have a mortality HR 4.5 times higher than an individual with a living grandmother.

Basically, similar to humans, female Orca whales live long after their ‘last reproductive event’, meaning they have the chance,- and the time, to help their own offspring with their offspring  – sorry if the word offspring is sounding weird to you now too.

PA

The study also linked the loss of a grandmother to years where there were fewer Chinook salmon – something these Pacific north-west whale groups like to eat – as she wasn’t around to use her knowledge to locate where the salmon would be; so Grandma Orca is pretty much putting food on the table as well.

Advertisements

Daniel Franks, the lead author of the study, told Business Insider

Post-reproductive grandmothers use their superior ecological knowledge to lead their group around foraging grounds.

The original ‘Grandmother effect’ in humans is a theory to explain the existence of menopause in women by identifying the value of extended kin.

PA

It suggests that by redirecting their energy onto those of their offspring, grandmothers can better ensure the survival of their genes through younger generations – something Orca grandmas apparently do now too!

Advertisements
Advertising

So, it’s likely human children would live longer than two years after their grandma died (you’d hope), but the study found Orca calves have a better chance at survival with grandma around.

Advertising

Long story short, grandmothers of all kinds are pretty great; whether that’s for survival purposes or for sliding you a sneaky fiver when your cousins aren’t looking.

If you have a story you want to tell, send it to UNILAD via story@unilad.com