Accuracy of aging ducks in the U.S. Fish and Wildlife Service Waterfowl Parts Collection Survey
ABSTRACT The U.S. Fish and Wildlife Service conducts an annual Waterfowl Parts Collection Survey to estimate composition of harvested waterfowl by species, sex, and age (i.e., juv or ad). The survey relies on interpretation of duck wings by a group of experienced biologists at annual meetings (herea...
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| Format: | Article |
| Language: | English |
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Wiley
2014-03-01
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| Series: | Wildlife Society Bulletin |
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| Online Access: | https://doi.org/10.1002/wsb.373 |
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| author | Aaron T. Pearse Douglas H. Johnson Kenneth D. Richkus Frank C. Rohwer Robert R. Cox Jr. Paul I. Padding |
| author_facet | Aaron T. Pearse Douglas H. Johnson Kenneth D. Richkus Frank C. Rohwer Robert R. Cox Jr. Paul I. Padding |
| author_sort | Aaron T. Pearse |
| collection | DOAJ |
| description | ABSTRACT The U.S. Fish and Wildlife Service conducts an annual Waterfowl Parts Collection Survey to estimate composition of harvested waterfowl by species, sex, and age (i.e., juv or ad). The survey relies on interpretation of duck wings by a group of experienced biologists at annual meetings (hereafter, flyway wingbees). Our objectives were to estimate accuracy of age assignment at flyway wingbees and to explore how accuracy rates may influence bias of age composition estimates. We used banded mallards (Anas platyrhynchos; n = 791), wood ducks (Aix sponsa; n = 242), and blue‐winged teal (Anas discors; n = 39) harvested and donated by hunters as our source of birds used in accuracy assessments. We sent wings of donated birds to wingbees after the 2002–2003 and 2003–2004 hunting seasons and compared species, sex, and age determinations made at wingbees with our assessments based on internal and external examination of birds and corresponding banding records. Determinations of species and sex of mallards, wood ducks, and blue‐winged teal were accurate (>99%). Accuracy of aging adult mallards increased with harvest date, whereas accuracy of aging juvenile male wood ducks and juvenile blue‐winged teal decreased with harvest date. Accuracy rates were highest (96% and 95%) for adult and juvenile mallards, moderate for adult and juvenile wood ducks (92% and 92%), and lowest for adult and juvenile blue‐winged teal (84% and 82%). We used these estimates to calculate bias for all possible age compositions (0–100% proportion juv) and determined the range of age compositions estimated with acceptable levels of bias. Comparing these ranges with age compositions estimated from Parts Collection Surveys conducted from 1961 to 2008 revealed that mallard and wood duck age compositions were estimated with insignificant levels of bias in all national surveys. However, 69% of age compositions for blue‐winged teal were estimated with an unacceptable level of bias. The low preliminary accuracy rates of aging blue‐winged teal based on our limited sample suggest a more extensive accuracy assessment study may be considered for interpreting age compositions of this species. Published 2013. This article is a U.S. Government work and is in the public domain in the USA |
| format | Article |
| id | doaj-art-7138f8f40aad432ebe8a479cdbd7d1f3 |
| institution | Kabale University |
| issn | 2328-5540 |
| language | English |
| publishDate | 2014-03-01 |
| publisher | Wiley |
| record_format | Article |
| series | Wildlife Society Bulletin |
| spelling | doaj-art-7138f8f40aad432ebe8a479cdbd7d1f32024-12-16T12:17:04ZengWileyWildlife Society Bulletin2328-55402014-03-01381263210.1002/wsb.373Accuracy of aging ducks in the U.S. Fish and Wildlife Service Waterfowl Parts Collection SurveyAaron T. Pearse0Douglas H. Johnson1Kenneth D. Richkus2Frank C. Rohwer3Robert R. Cox Jr.4Paul I. Padding5United States Geological SurveyNorthern Prairie Wildlife Research Center8711 37th Street SEJamestownND58401USAUnited States Geological SurveyNorthern Prairie Wildlife Research Center204 Hodson Hall1980 Folwell AvenueSaint PaulMN55108USAUnited States Fish and Wildlife ServiceDivision of Migratory Bird ManagementPopulation and Habitat Assessment11510 American Holly DriveLaurelMD20708USASchool of Renewable Natural ResourcesLouisiana State University Agricultural CenterBaton RougeLA70803USAUnited States Geological SurveyNorthern Prairie Wildlife Research Center8711 37th Street SEJamestownND58401USAUnited States Fish and Wildlife ServiceDivision of Migratory Bird ManagementPopulation and Habitat Assessment11510 American Holly DriveLaurelMD20708USAABSTRACT The U.S. Fish and Wildlife Service conducts an annual Waterfowl Parts Collection Survey to estimate composition of harvested waterfowl by species, sex, and age (i.e., juv or ad). The survey relies on interpretation of duck wings by a group of experienced biologists at annual meetings (hereafter, flyway wingbees). Our objectives were to estimate accuracy of age assignment at flyway wingbees and to explore how accuracy rates may influence bias of age composition estimates. We used banded mallards (Anas platyrhynchos; n = 791), wood ducks (Aix sponsa; n = 242), and blue‐winged teal (Anas discors; n = 39) harvested and donated by hunters as our source of birds used in accuracy assessments. We sent wings of donated birds to wingbees after the 2002–2003 and 2003–2004 hunting seasons and compared species, sex, and age determinations made at wingbees with our assessments based on internal and external examination of birds and corresponding banding records. Determinations of species and sex of mallards, wood ducks, and blue‐winged teal were accurate (>99%). Accuracy of aging adult mallards increased with harvest date, whereas accuracy of aging juvenile male wood ducks and juvenile blue‐winged teal decreased with harvest date. Accuracy rates were highest (96% and 95%) for adult and juvenile mallards, moderate for adult and juvenile wood ducks (92% and 92%), and lowest for adult and juvenile blue‐winged teal (84% and 82%). We used these estimates to calculate bias for all possible age compositions (0–100% proportion juv) and determined the range of age compositions estimated with acceptable levels of bias. Comparing these ranges with age compositions estimated from Parts Collection Surveys conducted from 1961 to 2008 revealed that mallard and wood duck age compositions were estimated with insignificant levels of bias in all national surveys. However, 69% of age compositions for blue‐winged teal were estimated with an unacceptable level of bias. The low preliminary accuracy rates of aging blue‐winged teal based on our limited sample suggest a more extensive accuracy assessment study may be considered for interpreting age compositions of this species. Published 2013. This article is a U.S. Government work and is in the public domain in the USAhttps://doi.org/10.1002/wsb.373age compositionAix sponsaAnas discorsAnas platyrhynchosAnatidaeblue‐winged teal |
| spellingShingle | Aaron T. Pearse Douglas H. Johnson Kenneth D. Richkus Frank C. Rohwer Robert R. Cox Jr. Paul I. Padding Accuracy of aging ducks in the U.S. Fish and Wildlife Service Waterfowl Parts Collection Survey Wildlife Society Bulletin age composition Aix sponsa Anas discors Anas platyrhynchos Anatidae blue‐winged teal |
| title | Accuracy of aging ducks in the U.S. Fish and Wildlife Service Waterfowl Parts Collection Survey |
| title_full | Accuracy of aging ducks in the U.S. Fish and Wildlife Service Waterfowl Parts Collection Survey |
| title_fullStr | Accuracy of aging ducks in the U.S. Fish and Wildlife Service Waterfowl Parts Collection Survey |
| title_full_unstemmed | Accuracy of aging ducks in the U.S. Fish and Wildlife Service Waterfowl Parts Collection Survey |
| title_short | Accuracy of aging ducks in the U.S. Fish and Wildlife Service Waterfowl Parts Collection Survey |
| title_sort | accuracy of aging ducks in the u s fish and wildlife service waterfowl parts collection survey |
| topic | age composition Aix sponsa Anas discors Anas platyrhynchos Anatidae blue‐winged teal |
| url | https://doi.org/10.1002/wsb.373 |
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