This article relates to birds. For clipped-wing aircraft, see Wing. Wing clipping is the process of trimming a bird's primary wing feathers or remiges so that it is not fully flight-capable, until it moults, sheds the cut feathers and grows new ones. Technique Wing clipping is usually performed by avian veterinarians, pet store employees, breeders, or the birds' owners themselves. It is generally carried out on pet birds, particularly parrots. If performed correctly, it is a painless procedure and is quite distinct from pinioning, which is carried out by amputation of the wing at the carpal joint. It is, however, not harmless as it can lead to indirect injury from falls, and is known to cause psychological distress. Techniques for clipping the wings vary primarily in the number of feathers cut and the amount of each feather left behind. A mild clip on one wing only can impair a bird's flight greatly, as it renders the bird unbalanced in the air. This can cause injury or death to the bird if it strikes a hard surface during a fall. In most cases, only the primary flight feathers are cut, and an equal number of feathers are trimmed on each wing to avoid causing the bird to become unbalanced in flight. The most common clip involves trimming the primary flight feathers below the level of the primary coverts (usually removing about half to a third of the length of the flight feather). This clip is quick and simple to do, but leaves exposed cut ends that occasionally may cause a bird to chew on the cut feathers. Another method of clipping involves cutting the flight feather above the level of the coverts, so almost the entire feather is removed. This clip does not leave any exposed cut ends, but as more of each feather is removed, fewer feathers should be cut. However, these cut feather stumps are still present and may irritate the bird, causing significant discomfort. Where parrots have clipped primary feathers, the moulting sequence of these birds renders them vulnerable to damage of their growing blood feathers. Most parrots have 10 primary feathers, numbered 1 (innermost) to 10 (outermost). The moult starts by the bird shedding and replacing a central primary feather, usually number 6. The sequence continues in both directions along the primaries, so the last primary feathers to be replaced are the innermost and the outermost ones