Question on trimming wings

[AinaWGSD]

I did a quick search but didn't really have the time or energy to read all of the results so I'm sorry if this has already been answered. What is the advantage of trimming only one wing? I work mostly with psittacine birds (parrots, cockatiels, budgies, lovebirds, lories, etc) and the general opinion is that if the wings are trimmed in these species it is best to trim both sides equally rather than just trimming one side. All of the larger species I've worked with through the zoo (pelicans, flamingos, etc) are either left flighted or pinioned so I really have no basis of comparison for non-psittacine birds. Also, does anyone know off-hand how many feathers you would need to trim on a large fowl or bantam? In the psittacines it is based mostly on size and flight ability Smaller, lighter birds like budgies and cockatiels generally get the first 8 feathers trimmed while medium and large parrots like amazons macaws usually only need about 5 trimmed (although I've seen amazons that were strong fliers fly and maintain height for several feet with as many as 6-8 trimmed).

 

[Imp]

Trimming one side is to keep them off balance. People have posted that their chickens could still get over a fence with one or both sides trimmed.

There's a good diagram here.

https://www.backyardchickens.com/LC-wingclipping.html

Imp

 

[Akane]

Since chickens do not carry out sustained flight I think being uneven is less of a concern. With small birds that have full flight capabilities you don't want to trim only one side because if they leap from somewhere high or get good initial lift for some reason they can end up being very off balance and crashing by the time they reach the ground. Chickens generally don't go more than a few feet off the ground and are large birds so probably less likely they'll crash with one wing trimmed instead of both.

My guinea cock and I just had it out on wing trimming. We're both bleeding now. I suggest getting a second person unless you have very tame chickens. It's rather difficult to hold the bird, hold the wing, and trim. That takes at least 3 hands so I was one short and he nailed me when I tried to pin his body and hold his wing with the same arm. Then to try to cut down on the claws raking across me I tried to trim those with him struggling and that's when he ended up bleeding so we are even but he has 3/4ths of a trim on one wing. I'm cleaning it up tomorrow with help.