How to set your camera to capture flying birds

Birds are those wonderful creatures that bring color to the sky and provide us with endless photo opportunities.  Over the years of photographing nature, one of the subjects I have always had difficulty with is photographing birds in flight.  Thanks to new auto-focus cameras that are very sensitive, this isn't as big a problem it has been in the past.  The primary reason is that there is now an AF button on the rear of the camera body that helps keep the birds in focus as they are flying.  It used to be you would have to press the shutter release button half-way down to focus and then recompose and shoot.  But there is a better alternative and it relates to the back-button auto-focus technique. The first thing you have to understand when using this technique is the various ways that auto-focus works.  Most DSLR's have three modes, single shot, continuous servo, and automatic. In the single shot mode, you select your focus point (in Nikon it is a little red rectangle) and press the shutter half way down and the auto-focus locks in and as long as you don't move or the subject doesn't move it will remain in focus. But what happens if the subject moves?  That is where continuous auto-focus comes into play.  The auto-focus in this instance will track or follow that moving subject as LONG AS YOUR FINGER CONTINUES TO PRESS THE SHUTTER RELEASE HALF-WAY DOWN. The auto mode generally uses single focus unless the camera determines the subject is moving and then would switch to continuous focusing.  Now, pushing that shutter release and then recomposing is difficult at best and this is where the back button auto-focus comes into play.  All you need to do is to activate this button (it will show you how in your camera manual.  I know you probably never read that thing but trust me, it is there) and then it is almost instinctive.  Your camera auto-focus must be set to continuous auto-focus and then you select your focusing point in the camera and put that point on the eye of your subject (or have it preset) and then as long as you hold down that back auto-focus button it will track and follow your subject as it moves.  It is really that easy.  The other really great thing is that when you release the button it acts like single auto-focus and you can shoot landscapes, scenery, and other static scenes because once you release the button, it stays in focus on where you had the focus selector set.  This also works for other wildlife as well.  In the case of this doe and fawn, taken today (Monday February 3) I noticed the doe and fawn together and they will often come up to each other and touch noses to recognize each other.  I had my camera set up and ready to go and watched as the fawn approached the doe, looking at her and then watched as the doe moved close to the mother.  At this point, I began shooting frames on continuous high frame advance and held my thumb on the back button auto-focus and kept the focus point on the eyes and in the space of 20 seconds had one shot where the noses touched (and many where they almost touched) and that was the winning image.  This would have been very difficult to achieve without the assistance of the back button auto-focus which kept the eyes in focus the entire time the deer were moving their heads.  So go ahead and give it a try and see if your wildlife shots don't dramatically improve.