Task: Question Answering
Input (English): Passage: Wing clipping -- A 'light' symmetrical wing-clip will allow a bird to fly down and land safely while indoors. However such a clip may not prevent the bird from flying when outdoors, since lift is generated in proportion to wind speed. Many escaped birds which are recovered are found to have been clipped. So, while a light clip allows downward flight indoors, it does not prevent a bird gaining lift if it should escape outdoors. Conversely, a more severe clip will certainly render a bird flightless, but it increases the risk of injury if the bird falls and hits a hard surface. In addition to the physical effects of wing-clipping, there can be adverse behavioural effects. Birds use flight as an instinctive reflex action and as their first means of escaping any threat: they take to the air to fly upwards and away from the source of the threat; their fear then dissipates. Where this behaviour is prevented by wing-clipping, this innate reflex action is denied the bird, and its fear will not subside. This may cause behavioural problems for the afflicted bird. When a bird needs to reduce its speed during flight, it employs a 'reverse thrust' action by extending its wing at the wrist joint and using the drag of its primaries as air brakes. While the reduced function of the clipped bird's primaries prevent propulsion and therefore lift, this also reduces braking abilities, so clipped birds may crash-land at higher speeds than full-winged birds. Clipped birds should not be taken outdoors unrestrained, as even clipped birds have been known to fly away when spooked outdoors.
Question: can birds fly if their wings are clipped
Output (English): 1