Some more photos have been added:
Discussion on what this bird is continues (I'll let others post
their own ideas). Showing that this bird is a hybrid (finding one or
more Surfbird chararcters that Great Knot lacks) would seem to be
pretty easy (much easier than showing that it is a pure Great Knot)
but I'm not covinced that some of the characters brought up are
definitive enough or are being seeing clearly enough to show
Surfbird ancestry. There do seem to be a few things that are, to
varing degrees, suggestive of hybrid origin (mostly the bill shape)
that will likely keep this bird off the state list.
The bird was roosting with Red Knots and a big flock of
Black-bellied Plovers on the dry sandy site well north of the
marsh/mudflats this morning but later moved south adjacent to the
3-stone monument north of the viewing platform.
Chula Vista, CA