These are both nice shots, but in my opinion they are a little dark (at least on my screen). You are not getting detail in the shadows. I shoot in manual mode, and take my exposure reading off the sky for birds in flight. If for example, the exposure setting from the sky reads an aperture setting of f/8, the shutter speed is 1/1600 of a sec, and the ISO was 200, I would make an over exposure setting of one and possibly two stops to achieve correct expose for my birds. It would tend to overexpose the sky some, but the bird would appear perfectly exposed with more detail in the shadows. My guess with the swallow and the stork would be about 1 stop more exposure. I'd stay at 1/1600 sec, and go to a f/5.6 for my aperture; with the ISO staying at 200. If that didn't quite work out, then I'd increase my ISO slightly. This is I get my exposures.
If I shoot in aperture mode, then I get my reading off the sky (like mentioned before), and adjust my exposure compensation to overexpose the sky by one or two stops, as necessary.
For white birds such as gulls and egrets, I find that I have to underexpose my sky reading, because the white birds will be drastically overexposed if I don't do that.
I appreciate the feedback. I’ve always found it difficult adjusting in rapidly changing conditions. It’s getting better with practice though. I do usually shoot in aperture priority or manual if conditions are relatively constant.