Have you ever seen a bird out foraging in the rain and wondered why it is not soaked to the bone? While every bird wears just one feather coat, different kinds of feathers – and even different parts of the same feather – can perform different functions.
The outermost tips of the main body feathers, called the contour feathers, are built so that the feather surface forms a fine, breathable but water-resistant mesh. This water-repellent property allows the downy bases of the same contour feathers, and other completely downy feathers, to stay dry underneath, allowing them to trap warm air.
Don't you wish we had such dry, warm, light, great-looking coats?