Greater Yellowlegs, Always Eating
The second thing that you will notice about most Sandpipers is that they spend a large portion of their time looking for food. I was able to watch one Greater Yellowlegs for the better part of an hour and it was feeding the enter time.
Greater Yellowlegs, Walking In Circles
The third thing that you notice after observing Greater Yellowlegs is that they tend to walk around in a large circular pattern when feeding. My guess based on this is that the bird walk in that pattern, in order to fool the bugs they feed on, into thinking that danger has passed and that it is okay to start moving about again. The Greater Yellowlegs then returns to catch the bugs.
Greater Yellowlegs: Tasty Looking Dragonfly!