East Bay Passerine Migration
There has been some discussion on migration in the east bay this fall. From my perspective, it has been a very good fall with three passerine fallouts so far at my house on the east side below Vollmer peak, The six days previous to today were very slow with only a couple of western tanagers and then WOW! This mornings sightings included: https://ebird.org/view/checklist/S59374573
Conditions were ideal with a dense fog bank above the house and the house in sun and no wind. The warbler waves will occur within 2 hours of the sun rising as the birds aggressively forage for active insects before dispersing into thelive oak forests where they are difficult see/find. In the morning - always bird the sunny areas for this reason - that's where insects are active. I believe the east side of the east bay hills is the migration corridor for hermit warblers as a relatively high percentage of the hermit warblers sightings for the greater bay area this fall on ebird is at the house location.
So far, over the same time period, the bayside migration has been VERY SLOW with only one yellow, one yellowthroat, and one pac-slope type bird the only migrants seen at my office on the bay in Emeryville. Its interesting how migration works and some areas are oasis and other areas are very quiet. PS -I have never seen a hermit warbler in Emeryville in over ten years of intensely birding this area - they are the opposite of yellow warblers who like the Bayfront.
Jim Chiropolos, Orinda