I am 90% sure that this is a Greater Yellowlegs, but I do admit there is a chance that it is the Lesser Yellowlegs. Because I didn't hear the call I cannot be 100% sure; but the slightly upturned bill, the bi-colored bill, and length of neck in proportion to body makes me almost certain it is a Greater Yellowlegs. If you have an opinion let me know, I'm open to the other possibility. Thanks.