La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Why Are Numbers of Mallards (Anas platyrhynchos) Declining In the Northeastern United States? The Possible Role of Reduction In Winter Feeding Sites (2017)
Auteurs :	H W Heusmann, Auteur
Type de document :	Article
Dans :	Wilson Journal of Ornithology (The) (129(3) September, 2017)
Article en page(s) :	528–534
Résumé :	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.
En ligne :	https://doi.org/10.1676/16-044.1

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