IMPORTANCE OF LAKE TONGA FOR THE WINTERING OF EURASIAN WIGEON (ANAS PENELOPE) AND GADWALL (ANAS STREPERA)Azarnia Sabah, Ziane Nadia and Benyacoub Slim
The monitoring of the numbers of Eurasian wigeon and gadwall ducks during two winter cycles (2014/ 2015 and 2015/2016) at Lake Tonga, shows that Eurasian wigeon is an early overwinter; this duck is very sensitive to the cold wave. . The gadwall is a late overwinter. Lake Tonga is classified as a nationally and internationally important wintering site for both species. The numbers recorded in 2014/2015 are higher than in 2015/2016, the drop in numbers is explained by climate change (the heat wave that reigned in Europe this year). The study of the diurnal behavior of the two species of Anatidae during their wintering at Lake Tonga showed that the two ducks exploit the studied site as a foraging area.