For example, wigeon Anas penelope move readily in response to disturbance (Madsen 1998b), but may be able to do so because habitat in the area is abundant.
3) species which are intolerant to disturbance, however, have low harvest including greater white-fronted goose Anser albifrons, wigeon Anas penelope, lapwing Vanellus vanellus and wood pigeon Columba palumbus, and thus hunting is unlikely to cause any impact on the populations;
In middle wintering stage (from December to February), the sex ratio of common teal Anas crecca (60.66% male, n=361) was male-biased while falcated duck Anas falcata (52.10%, n=286), mallard Anas platyrhynchos (50.00%, n=90) and Eurasian wigeon Anas penelope
(49.18%, n=183) were near parity.
ducks with clinical signs Common name (taxonomic name), n = 8 each Mild Severe Tufted duck (Aythya fuligula) ([dagger]) 4 3 Eurasian pochard (Aythya ferina) ([dagger]) 3 1 Mallard (Anas platyrhynchos) 0 0 Common teal (Anas crecca) 0 0 Eurasian wigeon (Anas penelope
) 0 0 Gadwall (Anas strepera) 0 0 Total 7 4 No.
The species included in the analysis are the following: Anas acuta, Anser albifrons, Anser anser, Anser brachyrhynchus, Anas clypeata, Anas crecca, Anser erythropus, Anser fabalis, Aythya ferina, Aythya fuligula, Aythya marila, Aythya nyroca, Anas penelope
, Anas platyrhynchos, Anas querquedula, Anas strepera, Branta bernicla, Bucephala clangula, Branta leucopsis, Branta ruficollis, Cygnus columbianus, Cygnus cygnus, Clangula hyemalis, Cygnus olor, Mergellus albellus, Marmaronetta angustirostris, Melanitta fusca, Mergus merganser, Melanitta nigra, Mergus serrator, Netta rufina, Oxyura leucocephala, Polysticta stelleri, Somateria mollissima, Tadorna ferruginea, Tadorna tadorna.
An example of this group is the Eurasian Wigeon (Anas penelope
), which breeds across the entire Palearctic region from Iceland to Siberia's Kamchatka Peninsula and winters primarily in the temperate and tropical zones of the Old World (32), where contact with West Nile virus is possible.