The link worked well. I will check it out. I remember that these birds made an odd movement of their heads when feeding. I see that the Peterson guide describes a "sewing-machine feeding movement" of the short-billed birds. This perfectly describes what I saw.
I think that these birds are dowitchers. If I am right, are they short-billed or long-billed? Photo taken on the shore of Monterey Bay at Santa Cruz, CA, 4/12/19, 9:00 AM.