This female Hooded Oriole (Icterus cucullatus) has been visiting a citrus tree in our backyard in Cotati. She's very secretive, so it's been difficult to get a picture. In the early evening, we are alerted to her arrival by soft "chut chut chut" notes. I'll have to try to record them.
P.S. To see a photo of a male Hooded Oriole in the same tree last year, see "Orange in the orange" on 18 June 2015.