This one was a hard one, unless you are an avid birder. They are Red Knots. These amazing birds have one of the longest annual migrations of any bird. Their breeding grounds are in the arctic, and they migrate as far south as Tierra del Fuego, at the south end of South America. One way, the trip is 9,300 miles!
One of their stopping points along the way is Delaware Bay, where their migration is timed to match the annual spawning of horseshoe crabs. The horseshoe crabs lay billions of eggs, providing a feast to prepare the Red Knots for the LONG flight ahead.