G'day Chris and All
I have to begin by stating that I've seen tens of thousands of Grey-tailed
Tattlers, but no Wandering Tattlers. However, regardless of what one has seen
or not seen, with waders, forget vocalisations and plumage minutiae, especially
when in moult. Instead, go for the bill. The bills of these birds have the
yellowing of Grey-tailed Tattlers and not the solid grey. As Alastair correctly
points out, the short culmen ridge, or nasal groove, is the most profound
evidence and chief diagnotic feature when splitting these two tattlers.
Generally one can ID a GT Tattler immediately by the black eye stripe
connecting to the straight, blackish bill. As Grey-tailed Tattlers come into
breeding plumage the facial striping can become a little indistinct (somewhat
in the manner of Wandering Tattlers) which can sometimes confound things. I
wouldn't recommend going off plumage characters so much in waders ever, but
these birds do not have the barred vents of the Wandering Tattlers.
No rare sighting for the bay, I'm afraid, but some nice shots anyway and . . .
any tattler is a good tattler!