Humming Birds

Its a challenge trying to photograph fast moving objects. I believe hummers are right at the top of the difficulty scale. The photo examples are from the Canon 7D with a 70-300mm lens. Its an older lens so does not have super fast focus capability. I tried to shoot the hummers using auto focus, but had little success. I then went to manual focus. I pre-focused on where the hummers might be. Out of 35 shots, ten were decent. Here are four examples.