This bird is very similar to another oriole common to Western Mexico, the hooded oriole. In addition to the streaking on the back, this oriole is bigger, with a straighter bill and more pronounced white edging on the wings. These differences are difficult to distinguish in the field so the photo was a big help.
Good detective work to ID the Streak-backed Oriole. Another lifer? How many did you get in Mexico?
23 LIfers all together! A great trip for sure