Wood ducks live at the Cincinnati zoo. They are free to fly in and out of the zoo and easy to photograph. Here is a drake in spring breeding plumage. The image is made with a Canon 1DX Mark II, 600mm lens, 1.4x teleconverter - both Canon version IIIs. A single AF point is active and I put it right on the duck's face using continuous focus assigned to two the rear buttons on my camera. www.gerlachnaturephoto.com
Note: all of the lenses I use are AF microadjusted for accurate focus - that is crucial. I have a detailed article about how I do it on my website blog.