Was at Gilman Park in Fullerton for a couple hours this afternoon (11:30-2:30). Overall the park was quite birdy, particularly the bathing spot/watering hole/warbler mecca downhill SW from Treeview Lane and the first walkbridge. At around 12:30, a warbler came down to bathe/drink that appeared to be a VIRGINIA'S WARBLER; similar to Nashville with a bright staring eyering, but with a dull gray/white belly contrasting with a brilliant yellow undertail covert. It came down about three times; the last time I managed some bad profile shots (sadly, with a twig obscuring the throat). I didn't see if after about 1:00 PM.

For those who haven't been to Gilman recently, it's my impression that the reeds and grasses just uphill of the bathing spot have been allowed to grow recently, thus obscuring the view a bit from the north. I would recommend standing a little west from the white structure to get the clearest angle of the water. The few times I saw the Virginia's Warbler on the ground, it hung around on the other side of the creek, just after it widens, NOT the narrow part of the stream where most of the warblers were bathing (and which is right now extremely obscured by grasses). This spot is dark due to the overhanging vegetation, so photography will be a challenge.

Other warblers included myriad Yellow, Wilson's, Orange-crowned, a few Black-throated Grays and Nashvilles, a Hermit, and a Common Yellowthroat. Also frequently at the water were at least 3 female/immature type Lazuli Buntings.
EBird checklist with bad photos of the Virginia's here: https://ebird.org/view/checklist/S48159011

Good birding
Samuel Bressler
Fullerton