American black duck populations have steadily decreased across the northeastern United States prompting researchers to examine causes of decline including habitat loss, hybridization with mallards, and competitive exclusion by mallards. We designed a survey of lakes and wetlands of the Saranac Lakes Wild Forest and estimated occupancy and detection rates for each species. Given the predominantly forested landscape and the low density of humans, we predicted American black ducks would have greater occupancy rates than Mallards. Our results show each species was approximately equally likely to occur and to be detected, and there was no evidence that mallards excluded American black ducks from habitats. Mallards did show greater affinity for habitats with more humans present compared to American black ducks. Less than half of the lakes and wetlands we surveyed were occupied by either species indicating there is an abundance of unoccupied habitats that could have population-level ramifications for both species.



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