The most practical shooting mode for nature photography is one of the semi-automatic modes: Program, Aperture Priority or Shutter Priority.
If you are only starting out, don’t worry too much about the exposure settings on the camera: concentrate on taking beautifully composed images. However, stay away from the completely automatic settings. Aim at using Aperture Priority as soon as you can – it is the way to go.
We almost always have our cameras set on Aperture Priority. If we want to achieve a certain shutter speed, we change our aperture and ISO until we reach it. Under certain circumstances we would set the camera to Manual mode, especially when using flash.
How you can take a similar image
Lens: Super telephoto lens.
Settings: Medium aperture. Medium ISO.
How: If you are fortunate enough to get fairly close to a turaco to take a head shot, you have to keep your own head. Use the camera on Av and close down the aperture by a few stops to make sure that the whole head is in focus. But when you dial down, keep an eye on the shutter speed. You don’t want camera shake. If the shutter speed becomes too low, increase your ISO.