24 A bird’s wing feathers (remiges) combine strength with lightness and flexibility. Compared with the rest of the body, the wings have relatively few feathers. Together, they form a perfect surface for flight. The outer wing Outer wing feathers provide most of the power for flight and prevent a bird from “stalling”. The outermost flight feathers can be spread open or closed up, to help with steering. Barn owl Green woodpecker Jay Lopsided Most flight feathers are narrower on the leading edge to provide lift. Slotted feathers The deep slot in this crow’s feather reduces turbulence. Coverts By overlapping the bases of the flight feathers, the coverts smooth the flow of air. Wider trailing edge Slot Narrow leading edge Fringe Barn owl Graded shapes Away from the wing tip, the feathers are shorter and broader. Swan Silent feathers The fringed edges of owl feathers help to make flight silent. Above and below Many wing feathers, such as these macaw feathers, have different structures on the upper surface, which makes it produce different colours. Tawny owl Adult starling Young starling Heavy-duty feathers The mute swan, which weighs up to 12 kg (26 lb), needs long, strong feathers to power its flight. Macaw