Feathers provide insulation and, since they're lightweight, they enable the birds to fly. There are two basic types of feathers: the streamline, contour-type feather and the fluffy, down feathers.
Feathers provide insulation and, since they're lightweight, they enable the birds to fly. There are two basic types of feathers: the streamline, contour-type feather and the fluffy, down feathers.
Contour feathers interconnect with tiny hooks to create a unified form for flight. The down feathers don't hook together, but are very good insulators. They help keep the bird warm.