Hiya Steve, first off, both shots are over-exposed, whites are blown out, that's probably the main cause of the chromatic aberration. White birds like this Little egret, in harsh bright sunlight are the hardest to get right. Consentrate on the bird not the background, spot focus will help but you'll still probaly need some minus compensation
Shutter speed if far too slow on the flight shot, you need minimum 1/1250th but I would say if you are new to bif, go even higher. The down side to this is upping the ISO but in good light it shouldn't be a problem
A good start would be posting the exif?, single focus point or group?, metering? ..... the more you can tell us about the shot, the easier it might be to pin point the problems. Even the uncropped shot looks soft, so maybe too slow for the focal length used,
If birds are your interest, pop along to the birding section, post a few photos and ask for advice/criteque