The study site of Garaet Hadj-Tahar (36 ° 51 ' 50 ' ' N, 07 ° 15 ' 57 ' ' E) 112 ha, has classified Ramsar site since 01/02/2001. It is part of the Guerbes-Sanhaja complex (northeast of Algeria). Our contribution consists in making a count of the individuals of the wintering population of the duck Gadwalls Anas strepa who frequent this site for two seasons (2013-2014 and 2014-2015) and follow their diurnal activities. The wintering population of the Gadwalls Duck uses the pond during the wintering season and the sleep activity dominates with 75.04% showing the role of the wetland's delivery field. The maximum number of 1026 individuals is recorded during the month of February 2015.