I think there are a few variables that change over time to affect your keeper rate. For me I have noticed the following :


1. I am more picky as to what constitutes a keeper.....this lowers the rate


2. I am more choosy as to when to push the shutter, waiting for the right light, pose, head angle etc etc... this increases the keeper rate even though I may take less shots.


3. I am paying more attention to camera settings and I am quicker at adjusting settings "on the fly"


4.The more I shoot, the more proficient I become at focusing and framing, learning to do to things almost without thinking


5. So over time I shoot less frames but more of them are good.....sort of a "wash" I think, saves time looking through a load of images though.


The day I spent in Florida was the first time I had ever used a 500mm lens and I went out from daylight to dark (6 am to 7pm with a 2 hour lunch break) actually with a guide so I took a lot of images. I used my Gitzo and Wimberly II head the entire time. Part of the time I was in a pontoon boat and other times in the water or on a sand bar. So I had the advantage of the guide knowing when and where to be under the given conditions to optimize the chance of getting good shots.


All that being said.....I am usually happy if I get one or two "great shots" every time out but my overall keeper rate is probably 10% at best. With birds you are dealing with a subject that rarely stops moving, combine that with all the environmental variables and it