Mallards have been replacing Black Ducks in human-altered landscapes in Ontario, 1996-2019 ...

• Main Authors: Roy, Christian, Iverson, Samuel, Meyer, Shawn, Dyson, Matthew, Cox, Amelia R.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Zenodo 2024
• Subjects: Agriculture; Anas rubripes; Anas platyrhynchos; Anas crecca; Aythya collaris; boreal shield; Branta canadensis; Forestry; helicopter survey; Population trends
• Online Access: https://dx.doi.org/10.5281/zenodo.13340871; https://zenodo.org/doi/10.5281/zenodo.13340871

The American Black Duck (hereafter Black Duck) has received much attention over the years as a popular game bird species that experienced historical declines on its wintering grounds. Declines may be due to changes in the quality and quantity of breeding habitat, competition with Mallards, or both. Although the Black Duck population has stabilized, spatial variation in regional population trends of Black Ducks on their breeding grounds can provide insight into the relative importance of these alternative hypotheses at provincial and local scales. We analyzed indicated breeding pairs count data collected in Ontario between 1996 and 2019 through the Eastern Waterfowl Survey to evaluate the correlation in breeding densities and trends of the five most abundant waterfowl species. We also tested whether habitat and anthropogenic disturbance variables could explain the distribution of those species. Overall, Mallard breeding pair densities increased across the survey area, while Black Duck breeding pair densities ... : Funding provided by: Environment and Climate Change CanadaROR ID: https://ror.org/026ny0e17Award Number: ...