Hawk Hill is a peak in the Marin Headlands, just north of the Golden Gate Bridge and across the Golden Gate strait from San Francisco, California. The hill is within the Golden Gate National Recreation Area.
It is the lookout point for the largest known flight of diurnal raptors in the Pacific states. Each autumn, from August into December, tens of thousands of hawks, kites, falcons, eagles, vultures, osprey, and harriers are funneled by the peninsular shape of Marin County into the headlands. Hawks avoid flight over water since warm thermals that provide lift are rare. Abundant populations of small mammals protected by the park are one resource that helps maintain the large number of visiting raptors in the Headlands during the fall, but the strong onshore winds hitting the hills of the Headlands provide cold updrafts and hot late summer days provide warm thermals that allow these birds to fly more efficiently.
Volunteers with the Golden Gate Raptor Observatory count and track this fall migration using bird-banding and radio-tracking techniques, all in cooperation with the National Park Service.
Raptor observations
The following table lists the annual average number of sightings by the GGRO in the Marin Headlands during autumn, for the years 2001–2009.The Pacific Raptor Report #32, Summer 2011.
Raptor species Sightings per yearTurkey vulture9,179Osprey105White-tailed kite92Mississippi kite< 1Bald eagle5Northern harrier751Sharp-shinned hawk4,187Cooper's hawk2,427Northern goshawk1Red-shouldered hawk464Broad-winged hawk123Swainson's hawk6Red-tailed hawk9,427Ferruginous hawk22Rough-legged hawk7Golden eagle20American kestrel542Merlin171Peregrine falcon199Prairie falcon8Unidentified1,291 TOTAL29,028
External links Directions to Hawk Hill
References