Age determination of mallards

Gary L. Krapu; Douglas H. Johnson; C.W. Dane

doi:10.2307/3800347

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Age determination of mallards

Gary L. Krapu·Douglas H. Johnson·C.W. Dane

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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.

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Journal of Wildlife Management Article

Source-reported bounding extent: 45.935238° to 49.000687° latitude; -104.048736° to -96.554507° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Gary L. Krapu, Douglas H. Johnson, C.W. Dane. 1979. Age determination of mallards. https://doi.org/10.2307/3800347

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