There are several approaches to taking photos of birds, today I went upstairs. From the top window I could look down on the birds. This can help in several ways. Flight is easier to observe as well as distance. Looking down to the ground it becomes obvious you can now take pictures of several birds without much of a depth of field problem. Instead of objects moving back into space they are pretty much on the same plane. This is a big help if you want multiple birds in focus in the same shot. As a matter of variety and interest some photographers actually carry a ladder in their vehicle. Changing your point if view is a nice change…and sometimes a real advantage.
This is an example of how shooting from above can help beet the depth of field problem.
billzine 