Documenting flocks of waders on the beaches is pretty standard. Try to get to a decent distance and photograph the entire flock a few times. This will help to give you a backup.
Then do a quick scan count using the bins to get an estimate of the different species present. This may be your only count if a raptor or some fishermen flushed them away.
I will use the scope and do a detailed count of the most identifiable species first, one species at a time. Normally I will count from left to right and then back again. Once done, it is time to go through the flock and look for the rarer species that I missed during the first two counts.
When all these are done, I will move in slowly for closer shots of the flock and the different group of the waders. I will normally capture some of the small species that were missed. I found the Broad-billed Sandpiper this way.
The last part is the one I like most, capturing them in action or in flight. The Lesser Sand Plovers are always chasing each other squabbling over food.
They also tend to fly from one part to another in search of a better feeding spot. There are always disturbances from raptors and people spooking them to take flight. You will have to anticipate these occurrences and get ready to press the shutter. Needless to say there will be some hits and many misses. But it was always great fun doing this. Great if you get some good images on the sensors. Here are some of these taken at Mersing Bay early this week.
Many thanks to Ron Chew for his inspiring photos and posting of the Mersing Waders.
Reference: A Field Guide to the Waterbirds of Asia. Wild Birds Society of Japan 1993.