On my last trip of the spring to the Carrizo Plain for wildflowers today (yes, there is still some fresh color at the south end of Soda Lake and along Caliente Ridge Rd.), a high point was Tricolored Blackbirds. There was a mixed flock of about 50 blackbirds on Sprague-Hill Rd. and later a group of about 120 at the base of Caliente Ridge Rd., both probably 80% or more Tricolored. I assume they are migrants, but if someone knows they breed out there somewhere, I'd love to hear about it.
Photos at: https://www.flickr.com/photos/marlinharms/