title: Wintering French mallard and teal are heavier and in better body condition than 30 years ago: effects of a changing environment?
abstract: Animal populations are exposed to large-scale anthropogenic impact from, e.g., climate change, habitat alteration and supplemental stocking. All of these may affect body condition in wintering dabbling ducks, which in turn may affect an individual's survival and reproductive success. The aim of this study was to assess whether there have been morphometric changes in Mallard (Anas platyrhynchos) and Teal (Anas crecca) over the last 30 years at a major wintering site. Body mass and condition increased from the 1950s-1960s to the 2000s in both species. The increase in body mass amounted to as much as 11.7%, with no corresponding change in body size. Improved body condition was maintained from early to mid-winter, but then converged with historical values for late winter. Our interpretation is that increasingly benign ambient winter conditions permit ducks to maintain better energetic "safety margins" throughout winter, and that converging spring departure values may be related to evolutionary flight energetic optima. The observed changes are consistent with large-scale climate amelioration and local/regional habitat improvement (both anthropogenic).
authors.affiliation: French Hunting and Wildlife Service. matthieu.guillemain@oncfs.gouv.fr
authors.forename: Matthieu
authors.initials: M
authors.lastname: Guillemain
authors.forename: Johan
authors.initials: J
authors.lastname: Elmberg
authors.forename: Michel
authors.initials: M
authors.lastname: Gauthier-Clerc
authors.forename: Grégoire
authors.initials: G
authors.lastname: Massez
authors.forename: Richard
authors.initials: R
authors.lastname: Hearn
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Champagnon
authors.forename: Géraldine
authors.initials: G
authors.lastname: Simon
mesh_terms: D000818:Animals; D001823:Body Composition / Q000502:physiology*; D001835:Body Weight / Q000502:physiology*; D057231:Climate Change; D004372:Ducks / Q000502:physiology*; D005260:Female; D005602:France; D008297:Male; D012621:Seasons