A multi-year survey on aquatic avifauna consolidates the eligibility of a small significant peri-urban wetland in northeast Algeria (Boussedra marsh) to be included on the Important Bird Areas network

Abstract

To date, Algeria has 22 wetlands designated as Important Bird Areas (IBA). However, other wetlands are also eligible for this network but have not yet been classified due to a lack of comprehensive studies demonstrating their ornithological importance. In this study, we are interested in the Boussedra marsh, located on the Algerian coast in the far north-east. The monitoring of the aquatic avifauna was carried out from September 2015 to August 2018. We applied the exhaustive count for small groups and the estimation of numbers for large groups. Two of the IBA categories were found to be significant, confirming the international importance of this wetland for waterbirds. Five species inhabiting the site are listed as globally threatened on the IUCN red list, namely, Oxyura leucocephala (Endangered), Aythya nyroca (Near Threatened), Vanellus vanellus (Near Threatened), Aythya ferina (Vulnerable) and Marmaronetta angustirostris (Near Threatened). Interestingly, 960 individuals of Oxyura leucocephala were recorded, i.e., over than 10% of the world’s population. Overall, the avian community of Boussedra inventoried between September 2015 and August 2018, has reached a diversity of 42 species, i.e., that’s about one-third of the national aquatic avifauna, consisting mainly of surface ducks, Rallids, waders, and gulls, making it one of the most diverse wetlands in the country. Although the monthly numbers of waterbirds in the marsh are low compared to the large Algerian sites (< 5000 individuals), they are still among the most important locally. Boussedra is a real wintering area, but it is also home to a diverse nesting population of 20 species, including four that are globally threatened according to the IUCN Red List, making it one of the most important nesting areas for waterbirds in Algeria.