Take it from me, photographing birds in flight is harder than it looks. They tend to fly out of the viewfinder faster than you can follow, or suddenly change direction, like to fly past as the sun has just set and the light is failing or is it they are just teasing you. Anyway I am alweays`pleased when i get an even half decent image.
White Faced Heron [Ardea novaehollandiae]. These two photos could be of the same bird, just taken in different spots.
If you are worried about all the bird pictures I've been taking lately, it is beacuse I can (I have a new new telephoto zoom, a sigma 70-300mm, for my pentax K100D). It is not a supper-zoom but it does give me the opportunity to get in close to birds. I also like submiting my photos to the flickr field guide to birds group. If you are into photographing birds I strongly recommend you join up.