Yellowlegs, Parker River National Wildlife Refuge, MA.
The greater yellowlegs is similar in appearance to the smaller lesser yellowlegs. Its closest relative, however, is the greenshank, which together with the spotted redshank form a close-knit group.
They migrate to the Atlantic and Pacific coasts of the United States and south to South America. They are very rare vagrants to western Europe.
Photo credit: Matt Poole/USFWS via Flickr