Ron Bolander was working at the Point Arena Lighthouse when he saw this raptor coming in from the west. He had his long lens on his camera and captured this photo.
You can see the distinctive white patch at the base of its tail. This hawk has an owl-like face that helps it hear its favorite food - mice and voles. Its facial feathers direct sound to its ears, just as an Owl's. Add this hawk's sharp eyesight and you will see why they are successful hunters of small mammals.
To hear the sound of a Northern Harrier, here is the link to the Cornell Lab of Ornithology: http://www.allaboutbirds.org/guide/northern_harrier/sounds
To see a photo of a female Northern Harrier, here is the link: http://www.mendonomasightings.com/2013/02/21/a-female-northern-harrier-as-photographed-by-craig-tooley/
Thanks to Ron for allowing me to share his photo with you here.