A lot of people have gotten to see the Mourning Warbler this afternoon. Thanks especially to Nick Lethaby, Brad Hacker, and Adrian O'Loghlen for helping refind the bird. I think when others were around looking for the bird today, I referred to it as a female. But it may in fact be a young male. It's more hooded looking than a lot of young Mournings you'll see photos of, and the hood is more gray, including some gray on the sides of the throat. That last feature gave me some pause, but I'm told that the break in the middle of the gray, particularly considering it's yellow in that break, is fine for Mourning. The eye ring is nearly complete, with just a slight break. But it's pretty thin, and thinner than you would expect in MacGillivray's.
As for birding this location, it's important to consider that this location is a private business complex and that it COULD be a little awkward having a bunch of people there at the same time. I'm not trying to discourage anyone from going there; just trying to make people aware. If anyone asks what you're doing, please be respectful and open about it. I don't think anyone will ask people to leave, but it could happen. If it does, then please comply. I have been asked to leave this place, but that was under a previous ownership, and before COVID-19. Nick tells me he's been there during the week this fall, and the offices don't appear to be occupied, although there are landscapers around. So, I think it should be OK.
Finally, directions, for those who haven't been there: the place is on the north side of Hollister, between the Storke/Glen Annie and Winchester Canyon exits, a bit closer to Winchester Canyon. The eucalyptus grove is directly north of the north end of Coronada St, the same street that dead ends on the south at the storm drain puddle in the butterfly grove. The two entrances to the complex are east and west of Coronado, and are well marked with "LogMeIn" signs. The bird is staying on the north slope of the basin where the eucs are (away from Hollister), in low vegetation (English ivy, etc.), often seen with an adult male MacGillivray's Warbler.
Elsewhere in the complex today, there were still some other migrants, including five or six Black-throated Gray Warblers, a couple of Yellows, and a couple of Wilson's, in the tipu trees with the many Yellow-rumpeds and sprinkling of Orange-crowneds.