Evidence for Black Duck Winter Distribution Change
| Autor: | Rodney W. Brook, J. Chris Davies, R. Kenyon Ross, David L. Fronczak, Kenneth F. Abraham |
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| Rok vydání: | 2009 |
| Předmět: |
Anas
animal structures Ecology biology business.industry viruses animal diseases virus diseases Distribution (economics) biology.organism_classification Fishery Geography Habitat Population index Animal ecology Flyway General Earth and Planetary Sciences American black business Ecology Evolution Behavior and Systematics Nature and Landscape Conservation General Environmental Science Population survey |
| Zdroj: | Journal of Wildlife Management. 73:98-103 |
| ISSN: | 1937-2817 0022-541X |
| DOI: | 10.2193/2007-424 |
| Popis: | The Mississippi Flyway midwinter population survey (MWS) indicates that American black ducks (Anas rubripes) have been rapidly declining for the last 10 years. We found a negative relationship between MWS and Ontario (Canada) midwinter counts for black ducks. Thus, as number of black ducks in the MWS decreased, Ontario midwinter counts increased. A shift in midwinter distribution of black ducks may be partly responsible for the decreasing trend in MWS counts. We recommend that midwinter black duck surveys be expanded to more sites in southern Canada and northeastern United States that currently are not sampled to better assess winter habitat use and improve the midwinter black-duck population index. |
| Databáze: | OpenAIRE |
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