The timberline sparrow (Spizella breweri taverneri) is a taxonomically controversial American sparrow. Usually treated as a subspecies of Brewer's sparrow, it is sometimes considered to be a separate species. 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.
It breeds at high elevations in Northern Canada.
References
Sources (2004): 2004 IUCN Red List of Threatened Species. A Global Species Assessment. IUCN, Gland, Switzerland and Cambridge, UK.