If you have the opportunity to attend a local camera club meeting you'll probably find that one of the most popular activities for photographers is photographing birds. They can be difficult to capture, (especially small birds) but when successful make rewarding images. Technically, it can present a challenge when photographing birds. A fast (short) shutter speed to keep a sharp image and a small aperture for adequate depth of focus, if the bird is relatively close. Keeping an uncluttered background also helps to improve the image. In one of the photographs below (the goldfinch on the sunflower) I replaced the background which was a wood fence with the shaded green background.