It was a very tedious long term trick to teach and after many months it still isn't perfect. The first method I used was a failure so I ended up giving up for a while and then decided to try a different method.
First off Kili was completely hand tame before I even attempted to teach this trick. If your bird doesn't like to be touched you can expect to get bit for doing this so make sure you work on handling your bird first.
I wanted the trick to look like this:
http://www.youtube.com/watch?v=WbUm0Ra5a-gNot the wimpy version like this:
http://www.youtube.com/watch?v=wTsNyqPDQaUSo let me tell you about what I did that didn't work first. I tamed her to let me open one wing at a time on her to inspect her feathers beforehand so I would grab the tips of both wings and pull them full apart to where I wanted them to be. I intended to shape the wings behavior. Well I'd worked on that for several weeks and she didn't like it and wouldn't do it on her own.
So I was kind of giving up and decided to train it to be the wimpy way of only opening them up half way. That one is easy to teach. You stick your pointer finger from each hand just under each wing and gently nudge them upward. Click, reward. Soon the bird "assists" you in raising them and you feel that you can use less pressure. You get the bird into a routine wings, treat, wings, treat... So it knows it's coming and now you start to recede the cue. You say "wings" or whatever your cue is (some people say "stick em up" and others say "eagle") and point your fingers close to the bird but don't touch or barely touch the wings and see if it will pick them up itself. If it doesn't you inch a little closer in, push with barely enough pressure to lift them. Teach it to do it itself. Then finally recede the cue even more to the point where you just point with two fingers and/or say the cue for results. Using two hands was getting annoying so I changed the cue to showing two fingers on one hand (pinky and pointer) as if I'm about to push her wings open and she would do it. So that's how you get what I call wimpy wings.
Now to get them open all the way it took much much longer than to teach the initial trick. Basically for months I've been doing a couple reps of that trick per day and only rewarding her for the biggest, best wing stretches and ignoring the smaller ones. Sometimes I'd hold up a really special treat (oatmeal, apple, whole peanut) and ask her to do wings for it and in her excitement she'd reach every farther to try to get the trick right. So it's been getting better and better little by little. Now she basically shows them all the way. I just need to get it more balanced cause she opens one wing more than the other and I need to work on duration. What's nice about the hand cue rather than verbal is that it demonstrates duration to the bird. For as long as you are holding he cue, they have to hold wings open. When you say the cue they just show it briefly and that's it.
In this video you can see the halfway stage in teaching the wings trick where she opens halfway and pushes it a little more to get the treat which I worked hard to encourage:
http://www.youtube.com/watch?v=yq6zgeMXHWsIn this newer video at 0:25 you can see me cue her to do wings and I reject it then cue her with my hand to encourage her to do it better to get the treat:
http://www.youtube.com/watch?v=--2I9nyziM8Now there are two other methods to teach this trick which did not work for me at all but could work for other kinds of birds. This is to either catch the natural behavior and put it on cue. Like if your bird every stretches both wings out at once, you click and reward every time and do a cue at the same time. The other way is to have the bird on your hand and drop your hand that it forces them to open their wings. That didn't work with my bird because she would start flapping, not opening wings for a glide. So obviously this only works if the bird opens the wings the right way and then can be put on cue with less and less dropping till eventually none.
Hope that helps.