It's that time of year when the days are getting imperceptibly shorter, birds start thinking of heading south, and a couple of hundred volunteer birders of the Golden Gate Raptor Observatory (GGRO) head to Hawk Hill to watch them.
Hawk Hill is at the southern tip of the Marin Headlands overlooking the Golden Gate Bridge, which naturally funnels migrating raptors from a fifty mile stretch into less than a mile. The result is a huge concentration of raptors. During peak season — which, not coincidentally, is usually within a day or two of the autumn solstice — you will typically see over 100 birds an hour from 12 or 13 species of raptors, including eagles, falcons, accipiters and some of the rarer buteo hawks.
It has to be seen to be believed, so if you're curious, come up to Hawk Hill and see for yourself. When you get there, on any day between late August and early December, as long as Hawk Hill isn't shrouded in fog, you'll find about a dozen volunteers with binoculars counting hawks.
The GGRO has been counting and banding raptors at this site for over twenty years. I have been volunteering for 6 years, and this year I have stepped up to be day leader of the Saturday II hawkwatch team. With the depth of hawk-watching experience on the team, it's not too onerous a job. The main responsibility is to ensure that the numbers are recorded systematically — this is a scientific study, after all — and, when the fog rolls in, to tell the team that it's time to hang up the binoculars for the day.
To help me keep up with the action, I built an RSS feed that contains a summary of each day's hawk watching, including a count of each species of raptor. The first week was a wash — fog every day — but we can expect to see numbers, particularly of the accipiters (Cooper's hawk and Sharp-shinned hawk), climbing rapidly over the next two or three weeks. Subscribe to that feed and you can get daily updates too; or even better, join us on the hill!