The Ruddy Turnstone is a small shorebird that we typically don’t get to see very often here in the Midwest, although I did see one last March when the weather was unusually warm for a brief period. As the name suggests, this migratory bird tends to look for prey by flipping over small stones and shells. I spotted these recently at the John Pennekamp State Park in Key Largo, Florida where they were happily jostling with a pair of White Ibises for food. The pictures below offer a rudimentary example of using depth of field techniques to focus on the desired subject.
The bird in the rear in the photo above is in focus while in the bottom picture, the bird in the foreground is sharp.
eclegein 
While on vacation in Florida, I often see these busy little birds foraging on the beach. Excellent comparison photographs of depth of field techniques!