Sandpiper

Lovely shots! Please correct the common & scientific names in edit. Thanks!

Great shots, mmarrafini516! These Sanderlings (see my proposed ID) don't nest on Galapagos; they arrrive during migration and some stay over the northern summer like these guys you spotted only two weeks ago. When the waves retreat they work through the freshly exposed sand hunting for small animals. When the waves come back they run up the beach. They are extreme migrants, breeding in the high arctic, and like to live in flocks, which gives them better protection from predators.