Timberline sparrow
The timberline sparrow 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 species, it was listed as being of least concern by the IUCN.Footnotes
