Lesser Yellowlegs, Tringa flavipes
Lesser Yellowlegs, adult molting, 8/6/06, Edwards NWR, Alviso
Lesser Yellowlegs, juvenile, 8/18/07, Edwards NWR, Alviso
Lesser Yellowlegs, juvenile, 9/15/07, Edwards NWR, Alviso
Lesser Yellowlegs, juvenile, 9/15/06, Edwards NWR, Alviso
Lesser Yellowlegs, adult Fall molting, 8/6/06, Edwards NWR, Alviso
Most Lesser Yellowlegs seen in the Bay Area during Fall migration are juveniles; the bird at the top and the directly left are adults.
Lesser Yellowlegs,  juvenile, 11/6/06, Edwards NWR, Alviso
Lesser Yellowlegs, juvenile (?) molting, 9/6/04, Edwards NWR, Alviso
A raised wing pose shows how the spotting and notching is all on the wing coverts, and the flight feathers are plain.
Lesser Yellowlegs, juvenile, 8/18/07, Edwards NWR, Alviso
Lesser Yellowlegs, juvenile, 9/3/07, Edwards NWR, Alviso
Lesser Yellowlegs, juvenile, with Greater Yellowlegs, 9/3/07, Edwards NWR, Alviso
In the SF Bay Area, we get Lesser Yellowlegs passing through in Fall migration where they can be seen together with Greater Yellowlegs, which are winter residents here. The two species are easily separable by size when seen together, as above and below, Greater being much larger, but size isn't always easy to judge on a bird seen alone. The call helps:  two syllables for Lesser, usually three for Greater. If they don't call, the size, shape, and coloring of the bill is the best identification mark. The Lesser's bill is typically about as long as the head, while the Greater's is half again as long. The Greater's bill is usually proportionately thicker, particularly at the base, paler toward the base, and slightly upturned, while the Lesser's is more uniformly colored and straight.
Lesser Yellowlegs (2) with Greater Yellowlegs, winter plumage, 8/31/05, Edwards NWR, Alviso
Lesser Yellowlegs, juvenile, 8/8/04, Edwards NWR, Alviso
At first I thought the bird shown left was this juvenile Wilson's Phalarope, which I had photographed in the same place just a week before. Sibley notes the "superficial" resemblance; the phalarope doesn't have anything like the notching and scalloping found on the upperpart plumage of this juvenile yellowlegs. For a picture of the two species together, which misleadingly makes them look very different in size, see here.
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