The White-crowned Sparrow (gambelli) is migratory and arrives in California as early as August but historically in September. It breeds in Canada/British Columbia, and I believe Alaska. I love photographing them, but mostly listening to their very sweet sounding calls. The black and white striping on the crown identifies the bird as an adult. It typically leaves for its breeding ground in April. There is a sub-species that is year round but I don't know if I would recognize the difference if I saw it.