Bird's down feather falling through the air. This type of feather makes up the under-plumage, providing insulation which maintains the bird's body temperature. The broad, flat vane of the feather is composed of many rows of comb-like barbs, projecting from either side of a thick central shaft. Feathers give a bird the ability to fly, as well as providing waterproofing, camouflage and plumage for mating displays.