25 The inner wing Inner wing feathers are generally shorter than those on the outer wing. As they are not subject to as much force during flight, their quills are shorter and their feathers are less well anchored. Feather from junction of wing and body A balanced blade The feathers between the inner and outer wing have curved quills and blunt tips. Inner wing feathers point away from the wind, so they do not need a lopsided shape to provide lift. In-flight markings The bright colours of many birds are revealed only when their wings are fully open. Sail feathers The male mandarin duck uses its sail feathers to attract a mate. Infrequent fliers The wild turkey lives on the ground and rarely uses its feathers for flight. Curlew Eagle owl Underwing feathers The underwing coverts lie close together to smooth the flow of air. Rook Bustard Coloured by its food The greater flamingo eats shrimp, which have in turn eaten algae containing pigments called carotenoids. It is these pigments that give the flamingo’s feathers their pink colour. Secondary feathers Secondary feathers are broader than primary feathers and cannot be controlled as much. These help the bird to lift and stay in the air. Jay Mallard Curlew Inner flight feathers Feathers make up about 5 to 10 per cent of a bird’s weight . Sail feather attached to base of wing Wild turkey