The purpose of wing-clipping is to reduce or prevent a bird’s ability to fly. This is a means of preventing it from getting hurt or escaping. Wing clipping is usually done by avian veterinarians, pet store employees, breeders, or the bird’s owners themselves.
Most birds can regain their flying abilities after wing-clipping if they are allowed to re-grow their feathers, some people prefer it and some people oppose I guess it depends on each individual, personally I prefer it but my way of doing it I do it slight so they can still fly and have fun around the house.
Techniques for clipping the wing the primary flight feathers that 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 ½ to 1/3 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 feather.
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.
Full-winged bird Social pet birds (such as parrots) may also be clipped both to restrict independence and in attempts to make them tamer and easier to manage in order to encourage them to socialize with their owners. Some parrots that show aggression to certain people or other birds may be clipped to prevent attack.
Clipped birds should not be taken outdoors unrestrained as even clipped birds have been known to fly away when spooked outdoors, you will have to put a harness for the bird which you can buy from a pet store they come in different sizes.
I prefer for my parrots (and I think most of my breeder friends agree) it is very important for the young parrots to learn to fly before wing clipping.
NOTES:
Pet birds that cannot climb well, including finches, doves, most soft bills, and some handicapped parrots generally should never be clipped, as clipping reduces their mobility too much. While clipped birds are less likely to fly out open doors or windows or into surfaces, they are more prone to some other household dangers, such as being stepped on or being injured by other household pets. Most flighty parrots can easily learn to avoid windows and mirrors in the home.
Clipped birds may be more likely to break a blood feather on the wing. Broken blood feathers can cause significant blood loss. Pulling broken feathers (sometimes necessary to stop bleeding) is painful, and can cause permanent damage to the feather follicle. Most tame flightier birds can be as easy to handle as clipped birds. The clipped feathers grow back in a few months.