In autumn, hawks and other birds of prey heading south for the winter funnel through Hawk Hill in the Marin Headlands north of San Francisco.
At 920 feet (280 meters) in elevation, the mountainous site, home of the Golden Gate Raptor Observatory (GGRO), is the perfect launching point for crossing the windy Golden Gate and San Francisco Bay. At one time, scientists believed the raptors resting at Hawk Hill were afraid of crossing open water, said Allen Fish, director of the GGRO. Now, Fish thinks the birds may be testing the area's tricky wind patterns and figuring out the easiest path.
"I've seen turkey vultures go directly over Golden Gate Bridge and ospreys fly out over the edge of the water," Fish told Our AmazingPlanet. "There are 19 different species, each with their own flying abilities," he said.