| Abstract: | A technique for distinguishing adult from yearling wild mallards (Anas platyrhynchos), from late winter through the nesting season, was developed by applying discriminant analysis procedures to selected wing feather characters of 126 yearlings and 76 adults (2-year-olds) hand-reared from wild eggs during 1974, 1975, and 1977. Average values for feather characters generally increased as the birds advanced from yearlings to adults. Black-white surface area of greater secondary covert 2 was the single most reliable aging character identified during the study. The error rate was lowest in females (3%) when discriminant functions were used with measurements of primary 1 weight and black-white area of greater secondary covert 2 and in males (9%) when the functions were used with black-white area of greater secondary coverts 1, 2, and 3. Methodology precludes aging of birds in the field during capture operations. |
| Genre: | Article |
| ProdID: | 1001538 |
| Citation Author: | Krapu, G. L.; Johnson, D. H.; Dane, C. W. |
| Citation Contributing Office: | Northern Prairie Wildlife Research Center |
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| Citation End Page: | 393 |
| Citation Issue: | 2 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Wildlife Management |
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| Citation Number Of Pages: | 9 |
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| Citation Phsyical Description: | p. 384-393 |
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| Citation Search Results Text: | Age determination of mallards; 1979; Article; Journal; Journal of Wildlife Management; Krapu, G. L.; Johnson, D. H.; Dane, C. W. |
| Citation Start Page: | 384 |
| Citation Volume: | 43 |
| Citation Year: | 1979 |
| Type: | citation/reference |
| Text: | Age determination of mallards; 1979; Article; Journal; Journal of Wildlife Management; Krapu, G. L.; Johnson, D. H.; Dane, C. W. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Mon, 1 Jan 1979 00:00 -0600 |
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