Monday, February 8, 2016

Dark-eyed Junco

On Friday Erika and I made a brief visit to the University of Minnesota Landscape Arboretum. I was happy to see a small flock of Dark-eyed Juncos. Although a few winter here in Minnesota, most travel further south from their transcontinental breeding range across Alaska, Canada, and some northern and mountain states.

Elsewhere in this blog I wrote about the “turbulent taxonomic history” that has been a “nightmare” for ornithologists. At one time, five species of junco were recognized. These days, there are only two species with at least 15 races (Nolan et al. 2002).

This junco’s brown back that contrasts with the gray head gave me pause. What is this junco?  A western Oregon Dark-eyed Junco?  Or an intermediate “cistomontanus,” a race that has been variously assigned to western Oregon and eastern Slate-colored Juncos?

This bird is probably a first-winter Slate-colored Junco. Its flanks are gray. Females can be quite variable, and may sport brownish backs and/or buffy flanks. The authors cited above write, "many records in East probably pertain to brownish variants of J. h. hyemalis (which are also often confused with oreganus group in the East)."

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