Breeding populations of Mallards (Anas platyrhychos) have declined 38% in the northeastern United States over the past 17 years. One reason for this may be the reduction of a unique wintering habitat, artificial feeding sites. I hypothesize that artificial feeding sites improved over-winter survival and pre-breeding body condition of Mallards and were utilized by a sufficiently large proportion of the northeastern Atlantic flyway population to improve the population's average annual survival and/or fecundity, thereby impacting population dynamics. In Massachusetts, the number of artificial sites where people fed Mallards declined 44% since 1999. Other states do not conduct surveys of feeding sites, but Christmas Bird Counts provide additional data on populations of wintering Mallards. A sampling of urban centered count circles from northeastern states reveal a 48% decline in numbers of Mallards between 1993 counts and those in 2013.
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1 September 2017
Why Are Numbers of Mallards (Anas platyrhynchos) Declining In the Northeastern United States? The Possible Role of Reduction In Winter Feeding Sites
H W Heusmann
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Anas platyrhynchos
artificial feeding
declining population
mallard
Northeastern
wintering