Hey Clark, thanks for the compliments on the photos and my Birds in Flight stuff. Its been one of those things I've been working on since we moved to Cedar Key and have a front row seat to some of the best birding around
When I'm shooting BIF, I try and keep my Aperature (F-Stop) pretty low to blur out the background and be able to keep my Shutter Speed pretty fast to stop the action. Keeping a low Aperature also helps in making the subject pop out of the image.
When shooting birds, I almost always shoot in AV mode, with Canon Cameras, which I shoot exclusively, but I think its called A Mode with the Nikons if that's what you're shooting.
I never shoot with the birds having the sun behind them, always with the birds flying into, towards or away from the sun. This allows the birds to be lit properly without the sillohette you're talking about.
If you're following the birds, you simply follow them while they're flying and stop taking photos as they pass through the sun. Wait till they get where the light is in your favor again, and start shooting again. But you need to have followed them the entire time while keeping them in focus or you'll miss the shot.
This involves some studying of your subject to know what they're going to do or at least know they're tendencies. When shooting BIF, I always have the Focus set to the Al Servo Mode which allows you to track a moving subject while keeping it in focus.
If you havent figured it out yet from watching them long enough, when watching a bird that is perched on a branch and it bends forwards and relieves itself, this means it's ready to take flight. They always lighten the load right before they launch...lol
This little bit of information has got me some awesome shots of various birds leaping into flight simply because I knew what they were going to do right after they let the load go.
As for metering, I always keep the camera set to center focusing which makes sure my bird is metered properly and exposed how I want it. For the bird at least. I'm not as worried about how the background is exposed, but as long as the bird or subject is exposed properly the background can usually be fixed afterwards.
This is something you have to remember while shooting things that are moving really fast. I'm more worried about getting my subject focused and captured so you cant always get a perfect image like you can with a stationary subject like a scenic or landscape scene.
Does that explain some of the techniques used to capture them? I'm strictly a novice at the Birds in Flight topic, but I've been studying many of the forums that go into great detail in this subject.
Hope that helps