Skip to Main Content
Acquisition of plumage polymorphism in white-throated sparrowsAuthor(s): Carter T. Atkinson; C. John Ralph
Source: The Auk 97(2): 245-252
Publication Series: Miscellaneous Publication
PDF: View PDF (381 KB)
DescriptionThe White-throated Sparrow (Zonotrichia albicollis) was thought to be polymorphic in breeding plumage, having distinct white and tan phases that are bimodal in distribution and independent of sex. Vardy (1971), however, submitted evidence that plumage type is determined primarily by age, sex, and molt cycle. We reexamined this question by measuring plumage characteristics on a quantitative scale with the Munsell system of color notation. Using techniques of numerical taxonomy, we examined immature and adult birds before and after prenuptial molt. Winter plumages were basically unimodal and continuous in distribution, whereas spring plumages were bimodal, as the birds separated into two morphs independent of sex. Winter plumage was significantly more variable than spring plumage. We hypothesize that winter plumage variability could function to maintain stable social relationships in winter flocks.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
CitationAtkinson, Carter T.; Ralph, C. John. 1980. Acquisition of plumage polymorphism in white-throated sparrows. The Auk 97(2): 245-252
- The role of plumage polymorphism in dominance relationshipt of the white-throated sparrow
- Implications of prebasic and a previously undescribed prealternate molt for aging Rusty Blackbirds
- Molt patterns, age, and sex criteria for selected highland Costa Rican resident landbirds
XML: View XML