Just reading Peterson Reference Guide to Sparrows of North America (2019) by Rick Wright, apparently on page 321, Timberline Sparrow (Spizella Taverneri), previously a subspecies of the Brewer’s Sparrow has been elevated to a species. A brief search of the internet didn’t produce any information to this effect so I’m not sure how this subspecies gained species status.
Here is what is stated in reference to Colorado; Still mysterious is the summer occurrence of Timberline-like sparrows in suitable breeding habitat at high elevations in the Colorado Rockies; it is not certain whether these birds are in fact Timberline Sparrows—or the altitudinal range of the Brewer Sparrow…
If this information is true the Timberline Sparrow would automatically ascend to first place as being the most difficult species to identify in Colorado if not for North America.
Anyone have any more information about the Timberline Sparrow status?