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Age-class determination of canvasbacks

Journal of Wildlife Management

By:
, , , and

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Abstract

A technique was developed to distinguish yearling from adult canvasbacks (Aythya valisineria) in the field during spring on the basis of white flecking on the distal ends of selected wing feathers. Covert feathers from adults had well-defined vermiculation patterns whereas feathers from yearlings lacked such markings. These age-related characters were confirmed by paired comparisons of feathers from the same captive birds in consecutive years and by discriminant analysis of feathers using densitometric measurements from known-age wild birds. Reflective densitometric measurements of greater secondary coverts for females and males were significantly different between 1- and 2-year-old and between 2- and 3-year-old canvasbacks. Greater secondary coverts were the best feathers for recognizing age-classes of males and females. Densitometric values indicate low variability among different observers and within samples.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Age-class determination of canvasbacks
Series title:
Journal of Wildlife Management
Volume
46
Issue:
4
Year Published:
1982
Language:
English
Contributing office(s):
Northern Prairie Wildlife Research Center
Description:
p. 894-904
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Wildlife Management
First page:
894
Last page:
904
Number of Pages:
10