The semipalmated Sandpiper gets its common name from the short webs between its toes ('palmated' means webbed). Feeding behavior consists of running along the water's edge or flooded mud flats, pecking and probing for small invertebrates on the ground, in mud, or occasionally under water. Typical diet consists of a variety of larvae, arachnids, plant seeds, snails and worms. When prey is in short supply, the semipalmated sandpiper may defend a feeding territory from other waders with aggressive behaviors including threat displays, chasing and fighting. When fighting, competing birds rush at one another with the neck feathers puffed out, the wings half spread and the tail elevated. —arkive.org
I've seen quite a bit of aggressive behavior and fighting amongst semipalmated sandpipers. Seems that the other bird's feeding area is better than any other. On this morning on a marsh in Long Island NY, I saw this semipalmated sandpiper come up with a nice catch, a good size worm. Not more than two seconds after getting it, another semipalmated sandpiper wants it and aggressively starts to fight for it. Of course the one with the catch will not give it up easily. It finds a solution for keeping the worm. It just squats in the mud and puts the beak with the worm in the mud. "You can't see it, you can't get it". Wrestling goes on for a few seconds when a third semipalmated sandpiper joins the fight. But more as an observer, perhaps waiting to see if somehow it may get lucky and grab the worm himself. It was over pretty quickly though when the first sandpiper was able to swallow the worm. Winner!!