I made an effort to bird today around the tip of Pt. San Pablo, but the sun never came up. Most of my birds were heard only, and something had to get quite close to me for it to be IDable in binoculars. I'm surprised I squeezed out the little over 30 species I did this morning. A total of 3 warblers, 2 tanager , 1 grosbeak, 1 chipping and 1 Lincoln's Sparrow were the bulk of the migrants. 2 White-crowns were in the oaks/switchbacks. Around 652am this morning in the marina, I heard two series of three high-pitched piping notes coming from a shorebird flying West over the bay. My instant thought was Solitary Sandpiper, but I have little experience with this species (and I was worried about an atypical Spotted). I figured if it was a Solitary, it would be the bird at the WTP leaving, as the WTP is just around the corner. A couple of us checked the WTP at different times this morning (I was there about 9am) specifically to see if the Soli had left, and we all found the Solitary Sandpiper was conspicuously absent. Of course, that doesn't confirm that I certainly heard a Solitary Sandpiper, but it increases the likelihood. I also made a quick stop to look for the Black-and-white again, and if it was there, I didn't see it.
In terms of other things... Brant's Cormorant have made a decent showing this fall in the Northern end of San Francisco Bay, where normally they are casual in Fall (but not during winter herring runs). I've had a handful (Pt. Isabel, Red Rock, Richmond Bridge), but the most consistent observer of these this year seems to be Alex Henry at the Albany Bulb. (Someone with the patience to baywatch!! :) Anyway, there's definitely some sort of movement going on with this species right now--perhaps the same factors that pushed higher than normal number of Murres into North SF Bay this August is the same thing willing Brant's into the bay?
It's my theory that Red-breasted Nuthatch might go through a minor irruption this year. It's a bit too early to tell, and the smoke certainly complicates things, but I've been watching solid numbers of migrants show up along the Richmond bayshore since mid-August, about the same numbers as what I saw last year. I counted 12 in the immediate vicinity of Vollmer Peak last week (the equivalent of straight-line hiking maybe 0.5 miles on the trail) which certainly seems higher than average. None of them looked to be recently fledged young. Perhaps this movement is just fire-related?
I had another Costa's Hummingbird at my house September 2-3, and the same bird made another appearance yesterday morning. From photos, this is different from the bird I had in July. Considering I've had 4-5 Costa's at my house in the last 2 years, and a good portion of the not-at-my-house county records are from the Central Contra Costa area, I wouldn't be surprised if this species migrate with some regularity over/thru Diablo. We already know that Diablo channels Calliope and Rufous in large numbers... why not Costa's in small numbers. This issue is probably complicated by the fact that Costa's are a Calypte, so Spring migration for this species might come earlier than when the sage at Mitchell starts to bloom --or earlier than when people start birding Diablo for spring migrants-- but if someone were to find a large stand of blooming flowers on the mountain in March... or possibly early July or September (early July and Sep. is when all the ones at my house show up), I would think Costa's would be a real possibility. Keep in mind that Costa's do already breed in the coast range of Western Stanislaus County...
Best of fall,