author(s)
Hacina Saidi, Souad Dadci, Ali Tahar and Moussa Houhamdi

abstract
The present study was conducted to study the diurnal behavior of the Common Pochard Aythya ferina during two consecutive wintering seasons (between September- May 2013/2014 and between September-May 2014/2015) at Lac des Oiseaux. Individuals of Aythya ferina arrive at Lac des Oiseaux from early September. The number of individuals fluctuates temporally between 200 and 500 individuals with an average of 350 individuals. A. ferena generally occupies the central regions of the lake near the Scirpus lacustris and away from human disturbance. The diurnal behavior of the species has shown that Lac des Oiseaux was used as field daytime foraging (feeding was 52%). This activity was followed by swimming 21%, preening 15%, sleeping 10% and finally flying 2%