The Lesser Yellowlegs is in the foreground and a Greater Yellowlegs in the back. Notice how much larger the Greater Yellowlegs, but you don't often have them together to compare.
FIELD IDENTIFICATION: The Lesser Yellowlegs is a spring and fall migrant through Wise County. In breeding plumage, it has a gray back with white speckles, slightly barred flanks, and streaked head and neck. Non-breeding plumage is slightly paler, there are no bars on flanks, and the head and neck are less streaked. The legs are bright yellow, and the beak is straight.
The Greater Yellowlegs is very similar, and the size difference between them is not useful unless both species are side by side. Instead, the relative length of the beak is helpful. The Greater Yellowlegs' beak usually is about one and a half times the length from the base of the beak to the back of the head, whereas the Lesser's is usually only a little bit longer. In breeding plumage the Greater Yellowlegs is also said to have more barring on the flanks.