The biting wind seems to find the smallest crack in your several layers of clothing to nip at exposed flesh, your hands feel frost-bitten even though you’ve got your thickest gloves on, and the tip of your nose is so cold that you can no longer feel it. Yet there on a fence post directly in front of you, equally exposed to the wintery weather, is a chirpy wee Robin, singing its heart out, seemingly oblivious to the chill. How does it do it?

Well, the answer is in the fluffing up of its feathers. If you’ve ever slept under a down- or feather-filled duvet, you’ll know how incredibly warm feathers can be, and that’s especially true for our wee Robin. You see, feathers are a brilliant form of insulation material – feathers trap air close to the bird’s body so, in winter, they trap the warmth of the bird’s body heat. The more fluffed up the feathers are, the more warm air they trap, the more cosy is our little Robin.