I’ve seen this bird for weeks but was never able to get an image until this afternoon, when it spent some time circling around the nature area on the north side of the park. Raptor expert John Davis identified it as an adult female Northern Harrier. The females are considerably bigger and more dangerous than the males. Both the Burrowing Owl and the neighboring ground squirrels dove for cover while this marauder cruised overhead.
Unlike kites and hawks, which typically hover or perch at altitude and dive when they spot prey, the harriers swoop low, sometimes just inches from the ground, counting on surprise to catch prey. They take voles by preference, and will take mice, rats, small rabbits, ducks, meadowlarks, sparrows and other small birds if they can catch them.