I photographed this bird in 2012, and have seen it in the park occasionally since then, although without being able to get a good picture. I have also seen it in the nearby McLaughlin Eastshore State Park (Berkeley Meadow). This raptor has a trademark style. Instead of swooping and cruising like most other birds of prey, it hovers. When there’s a good breeze it maintains its position with subtle shifts of the wingtips. Otherwise it holds position by flapping its wings like a big, slow hummingbird; see video below. Its eyes, surrounded by a black patch, point straight down. When it locates its prey, it drops like a stone and seizes the victim in its talons. Its menu has been studied and consists more than 95% of small mammals. In my opinion the abundant ground squirrels in the park are a bit too big for this bird, at least when full grown. It hovers further up the hills where ground squirrels are not so common, and where smaller prey like field mice and gophers dominate.