There’s not a great choice of nest-building materials in the Antarctic.
Pretty much the only things available to gentoo, Adélie and chinstrap penguins are pebbles, which at least serve to raise eggs off the frozen ground. Pebbles don’t collect themselves and can be hard to find. The males tend to do the bulk of the work and will readily steal from their neighbours to fulfil their parental duties.
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What is pebbling?
There are plenty of videos out there of penguins passing the stones from beak to beak to a mate on the nest. This behaviour has inspired the word ‘pebbling’, which has come to describe the swapping of little gifts between human friends or lovers.
Why do penguins give stones to each other?
If the internet is to be believed, pebbles play a crucial role in gentoo penguin reproduction. The story goes that males try to woo a female by presenting her with a pebble, and she chooses the suitor that brings her the smoothest one. It’s a lovely idea, and easy to imagine that such a ritual might give females clues about a male’s potential as a provider, but any evidence that it’s actually true is hard to come by.
Main image: breeding pair of gentoo penguins creating a nest/Getty
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