Glossy Ibis are a casual species (vagrants, more uncommon than 'rare') in California. 100% of Glossy Ibis recorded in CA on eBird were between May-August. In basic plumage White-faced and Glossy are incredibly difficult to differentiate. The main difference between the two is the iris color. It is dark on Glossy and red on White-faced. I don't think iris color is reliable here given the post-processing of the photo.
Page 96 in National geo graphic North America western edition. Says "Recorded through much of the west; most records are from California and New Mexico."
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