I am thinking the one in front is a Lesser Yellowlegs and the one in back is a Greater Yellowlegs. The one in front looks smaller but if they were the same size birds should look larger... Also the one in the back has a slightly upturned bill.
the bill seems to have a slight upward turn; later I have an observation of what I think are both a Greater and Lesser Yellowlegs together
San Diego County, California, US
The Greater Yellowlegs (Tringa melanoleuca) is a large North American shorebird, similar in appearance to the smaller Lesser Yellowlegs. Its closest relative, however, is the Greenshank, which together with the Spotted Redshank form a close-knit group. Among them, these three species show all the basic leg and foot colors found in the shanks, demonstrating that this character is paraphyletic (Pereira & Baker, 2005). They are also the largest shanks apart from the Willet, which is altogether...