this is the first lesser yellowlegs I've ever seen right next to a greater yellowlegs. It was great to compare the bill sizes side-by-side. the lesser is much smaller and slighter, puny legs compared to the greater. the wing tips are quite dark in flight compared to the more evenly brown greater, also. Heard both - the tu-tu-tu of the greater and a different two-note call from the lesser.
The Lesser Yellowlegs (Tringa flavipes) is a medium-sized shorebird similar in appearance to the larger Greater Yellowlegs. It is not closely related to this bird, however, but instead to the much larger and quite dissimilar Willet; merely the fine, clear and dense pattern of the neck shown in breeding plumage indicates these species' actual relationships.