Function of a temporary wetland for wintering anatidea and coot: Mekhada Marsh (North East Algeria)

摘要

Mekhada is a temporary wetland located in northeastern Algeria fill during winter. Its surface varies between 3500 and 8000 ha according to rainfall. Its shallow depth exposed it to a large and rapid drying. These parameters make it an important wintering habitat for water bird, especially Anatidae and Coot. 11000 birds for 10 Anatidae and Coot were counted during winters 2013 and 2014. Eurasian wigeon and Eurasian teal are the most abundant. Analysis of evolution of Anatidae and Coot abundance reveals a delay of approximately one month in arrival and earlier departure of birds. This result is caused by late filling of the marsh due to delay of autumn and winter rains; and a tendency for birds to leave their wintering habitat earlier. Birds exploitthe habitat as it is filled with water. In general, they are distributed mainly in the center and south of the marsh, which is the largest area. This distribution is due to the shallow depth in the southern sector that allows accessibility to food resources but also to the quietness of this area. Relationship between Anatidae abundance and water depth allows to verify that Enrasian wigeon and Eurasian teal exploit a larger range of depths than other species. This ecological plasticity is a response to search for additional food resources. Mekhada marsh face rains concentration over a short period. If this trend where be confirmed, this habitat will no longer be able to host wintering bird.