My last 2 entries were VERY long and information-dense, so this will be something shorter and lighter - enjoy!
County bike-birding totals as of September 16, 2018
Even though I'm equidistant from San Francisco and Santa Clara, I bike to SF more frequently than I do to SC. That's because the wind in the Bay Area usually blows from the northwest and builds through the day. There's usually little-to-no wind when I leave at 6:30am, so there isn't much difference between riding northwest or southeast on the outgoing leg. But the return leg is a completely different story. What's often a 15 MPH tailwind behind me returning from SF is an equivalently strong headwind returning from SC. That headwind can be hugely impeding and turn what was otherwise a nice day of birding into a royal pain in the ass - and legs. I can only ride south when the forecast calls for very light afternoon winds. It's just not worth the headache otherwise. I'm hoping to do an overnight trip to SC (and Alameda) in October, so stay tuned for that.
Bay Area is expensive, but you get what you pay for!
It's here that I want to draw a parallel to pelagic trips. When strong winds are forecasted, the universal pelagic strategy is to run directly into them on the outgoing/morning leg. The hope is to reach the deepwater before those winds strengthen to the point that they make travel unnecessarily uncomfortable or impossible. It's then as simple as turning the boat downwind and surfing the building gales back to port. Those windy day courses are shown as yellow traces on the maps below. If we went any other direction than straight upwind on those windy days, we'd have a VERY bumpy and possibly painful ride home in the afternoon. Days with light winds (or - very rarely - with southwest winds) permit alternate routes, and examples of those are shown as green traces below. The bottom topography of the Monterey Seavalley offers more dichotomous options than does the straight shelf edge offshore from Half Moon Bay, but the idea is the same.
Pelagic routes from Monterey (L) and Half Moon Bay (R)
This is what popped into my head on my ride to San Francisco this morning, so I figured I'd share that observation with you. Cars are largely insulated from wind governance, but the same cannot be said for bikes or boats. Here was today's main quarry, a Black-throated Sparrow that's been hanging out behind the VA Hospital in NW SF for the past week. I also poached a previously reported Red-eyed Vireo in Golden Gate Park. As great as those birds were, they were outdone by a Blackburnian Warbler others and I found while searching for the vireo. 50 miles and 3 birds for my Peninsula bike list - not a bad morning!
Digi-binoc'd juvenile Black-throated Sparrow