One problem with telephoto primes is the fixed field of view which may not match the desired image size. When I use primes with average focal lengths like 50mm it is less of a problem because I can just walk forwards or backwards to adjust a composition. With a telephoto prime, walking is often not practical, so I have the problem that I am only getting 3/4ths of the woodpecker and his feet are not in view. If the subject is a little too far away, I can just crop the photo or use a teleconverter, but if it is too close, switching out the lens seems to be the only option, and by that time the bird is gone.
Are there any innovative strategies for dealing with this problem?