This is driving me crazy. I can tell Greater from Lesser Yellowlegs when they are side by side or when they are near another species whose relative size I know (or can look up). Otherwise, I'm clueless. I have studied Paulson's Shorebirds of North America, The Shorebird Guide by O'Brien, Crossley and Karlson, plus Sibley, etc. If anyone can help, I'd be eternally grateful. First photo is of a Yellowlegs taken an Baskett Slough on Sept. 19. Second photo is of a Yellowlegs taken an Baskett Slough on Sept. 20. Is it possible to tell what they are from these photos? If so, how?
I am making progress on the Western vs. Least problem: I just look at the legs.
Addendum: Two knowledgeable birders have responded to say these are both Greaters. The base of the bills are bulky. Lessers have needle-like bills. Okay, here's a photo I took at the Oregon Shorebird Festival of 2 Greaters and 1 Lesser. (I know because of the size difference.) I"m not sure I would be able to call the Lesser's bill needle-like if I didn't see it with the Greater. Is there anything else to be seen in this photo that is different between the two (other than size)?