Gannet in flight

I'm waiting for the ID of another New Zealand flower photo I wanted to post tonight, so instead I'll go back to gannets. I will let you in on a little secret. The sky was totally grey and boring on the day I shot this. So the sky in this photo is painted in with Photoshop using the gradient tool. Not bad, eh? You'd be hard-pressed to find any artifacts from the editing. I used the smudge tool to touch up the edges where the sky met the bird in a couple of places where it was obvious (where the bird's color contrasted least with the sky color, i.e., around his tail and at the back of his head/neck).

My photographer friend Paul Butzi says you can learn about the world through doing photography, and that's one of the main reasons he does photography. I learned some things about gannets by photographing them that day at Muriwai Beach, though to really learn more about them, I'd need to spend days around them photographing them. And I also think one needs to supplement the photography with something else, some sort of research into what other people have learned about them and how they have classified them. For example, I'd really like to know what those white feathers are called at the trailing edge of his wings, near the root of the wing (inside where the black feathers start). I'm sure there's a name for them. There seems to be a name for everything biological. I wanted to describe to you how that was one of the edge spots that I edited with Photoshop, but I didn't know the word to use. I could look it up in one of my birding books, but they are all still packed away from my move. If anyone happens to know the word, please post it here in the comments. I did a quick search in Google, but this chart I found doesn't seem to give me the answer that I think must exist.