"T4" . . . "The timberline sparrow (Spizella breweri taverneri) is a taxonomically controversial American sparrow. Usually treated as a subspecies of Brewer's sparrow, it is still considered a distinct species Spizella taverneri by many authorities. While the timberline sparrow recognizably differs in some details, there is little reproductive isolation between the taxa.When it was still considered a good species, it was listed as being of least concern by the IUCN."@en . . "TNC" . . . . "Spizella taverneri" . .