The first H5N8 outbreak among poultry in the Netherlands occurred on November 25, two weeks after the first detection in wild waterbirds and coinciding with increasing death reports in Eurasian wigeons. This time lag might be related to the limited mobility of wintering Aythya ducks, which, in contrast to Eurasian wigeons, rarely fly over land between foraging and roosting sites.
After potential double-counts were excluded as much as possible, [approximately equal to]13,600 wild birds of 71 species were reported dead (Table); 49% of all carcasses were identified by species, most of which were tufted duck (Aythya fuligula [39%]) and Eurasian wigeon (Anas penelope [37%]).
The sex ratio of Eurasian wigeons in Poyang Lake was balanced and had slight differences compared with the female-biased sex ratio in Tai-hu Lake and the male-biased sex ratio in the UK and Denmark (Table I, III).
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.
By the third week of October migrant wigeon, gadwall and divers begin to show up.
Bill took a dandy drake and I connected on a drake gadwall as it sucked toward the mixed mallard and wigeon blocks.
The ducks could be divided into a high-excretion group consisting of tufted ducks, pochards, and mallards, and a low-excretion group consisting of teals, wigeons, and gadwalls (Figure 2, panels B and D).
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.
When he returned, Turner told him an approaching hawk had spooked many of the wigeons
, but the bird in which he was interested remained on the water.
Finally, the arrival of the first Wigeons
at Conwy and Pink-footed Geese at Martin Mere are signs of the changing season.
common pochard Aythya ferina, northern shoveler Spatula clypeata, Eurasian wigeon
Mareca penelope, northern pintail Anas acuta; Nagy et al.
"A Eurasian Wigeon
on the left, female, young," he whispers, and takes a shot of it with his Nikon.