Use camera in Shutter speed mode (usually S or Tv on your mode selection button). Use a shutter speed of no more than 1/250s (1/500s is even better).
Check the aperture proposed by camera. If it’s not a middle aperture (for example f/8), raise your ISO. A mid aperture will give you enough depth of field to get entire bird in focus.
Try to use a telephoto lens, it will be easier to fill the frame. If it’s not enough, you can crop in post-production to bring more focus to the subject.
Focus on the eye. After all, the image will be a bird portrait, and as you know the eyes are catching you 🙂
Use continuous focus.
Use single focus point, choose middle point for faster focus. If needed, crop your frame in post-production to meet rules of thirds for example.
Do not crop more than 25% in post-production, as this will lead to potentially unclear images.
Interested in more photography tips? Check my book, Essential Photography Tips: Get the Most out of Your DSLR.