This is SO well done.
Gorillas hum and sing during mealtimes according to scientists who have recorded western lowland gorillas ‘performing’ while eating in the forests of the Republic of Congo.
Primatologists, including Gorillas in the Mist author Dian Fossey, have reported humming and singing by wild mountain gorillas before, but the new research, published in science journal PLOS One, sought to explain the purpose of this behaviour.
The scientists, led by Eva Luef at the Max Planck Institute for Ornithology in Germany, found that while in captivity, every member of a gorilla troop tends to sing while eating, in the wild, it was generally only the dominant ‘silverback’ males who sang.
Have a listen to two males, Kusu and Balema, below (you’ll have to turn up the volume on Balema to hear him over the background noise):
Kusu's basso profondo hum
Balema sings a soft melody
Classic FM hasn't heard basso profondo as good as Kusu's since our last visit to a Russian Orthodox church, where exceptionally deep bass is fairly typical of their choral music. Have a listen to this...
Back to the science, and Luef believes that the purpose of the singing could be to notify the rest of the group that it’s dinner time. It might also signify contentment at whatever is being eaten.
Brian Owens in the New Scientist explains:
"…As well as possibly signalling contentment or pleasure with the food – a sort of gorilla version of 'om nom nom' – the activity might be the silverback’s way of informing the group that mealtime is continuing and it is not yet time to move on."
Luef told Owens: "[The silverback] is the one making the collective decisions for the group. We think he uses this vocalisation to inform the others, 'OK, now we’re eating'."
She added: "They don’t sing the same song over and over," says Luef. "It seems like they are composing their little food songs."
Ali Vella-Irving, who looks after gorillas at Toronto Zoo in Canada, said humming and singing is a frequent part of mealtimes there. "Each gorilla has its own voice: you can really tell who’s singing.
"And if it’s their favourite food, they sing louder."