Oct 2007 Auk: White-throated Sparrow Morphs

A genotyping assay to determine plumage morph in the White-throated Sparrow (Zonotrichia albicollis).

This simple methods paper was interesting to me because it explained what is known about the causes and differences in the two color morphs of White-throated Sparrow, something I haven’t read about before. As you may or may not know, there are white-striped and tan-striped morphs of White-throats, which may be mistakenly viewed as male/female or adult/immature. They can in fact be either gender and adults, much like red and gray phase Screech Owls. This paper develops a simple PCR method for genotyping individuals not identifiable by morph to plumage (basic-plumage or immature birds).

(Source)

This is possible, as the authors explain, because the morph differences are caused by a chromosome inversion present in white-striped forms. The exact biochemical effects of this inversion have not been worked out, but there are noticeable behavioral differences that accompany the plumage differences. White-stripe males and females are more aggressive and sing more frequently, while tan-stripe individuals spend more time in parental behaviors (see citations in paper for more information).

Hopefully the genotyping method Michopoulos et al. have developed will lead to further insights into this strange system!


Vasiliki Michopoulos, Donna L. Maney, Caroline B. Morehouse, and James W. Thomas. 2007. A genotyping assay to determine plumage morph in the White-throated Sparrow (Zonotrichia albicollis). The Auk. Vol. 124 No. 4 1330-1335.