Indigo Bunting (Passerina cyanea)

This singing adult male seems to have taken up a summer territory in San Francisco. It was first found by Ben Dudek on 17 May and has been seen daily since then. It is rare but regular in California but normally breeds through eastern North America where it replaces the western Lazuli Bunting. They winter in the tropics often forming flocks with other species such as the smaller Blue-black Grassquit. Note the straight culmen (top of bill) which helps distinguish Indigo Bunting from similar Blue Bunting of Mexico and Central America which has the upper mandible more arched.