How Do Birds Puff?

And just like the coats people wear, birds tend to get puffier in winter. “A bird's body heat warms the air between its feathers,” Marra explains. “So birds fluff up in the cold to trap as much air in their feathers as possible.

How do birds puff themselves up?

Feathers provide insulation and are coated with an oil that promotes waterproofing. Birds fluff up their feathers in the cold so they trap as much air as possible in tiny pockets of air to hold in body heat. Wild birds also roost together or find tree cavities to keep heat.

Why do birds puff up their head feathers?

They don't actually blow themselves up, but rather fluff up their feathers. This happens regularly in cold weather, as birds are trying to keep warm. Being small, they would lose too much heat on a frosty winter's day if they didn't have the insulation of their feathers to keep out the cold.