WIWO-reports published

The Banc d'Arguin is one of the key wintering areas for waders and other waterbirds in the world. Despite its relatively modest size it supports higher numbers of wintering waders than any other site on the East Atlantic Flyway. It holds the highest densities of wintering waders known from Europe and Africa. Since 1973 only 4 more or less complete counts have been carried out in the area during the wintering period of northern birds (in 1979, 1980, 1990-94 and 1997). The more recent counts show that important changes in bird numbers have occurred. These changes, as well as the high international value of the Banc d'Arguin, justify more frequent monitoring. In January 2000 the Parc National Banc d'Arguin has been visited in order to carry out a count of all waders and waterbirds in the area.

The aims of the project were:

• to carry out a complete census of waterbirds and compare the total numbers with published results of earlier censuses, in order to establish population developments;
• collect counting results of well-defined count units, to be used later in analyses of future monitoring plans;
• transfer of knowledge and expertise to Mauritanian counterparts in setting up and carrying out a census like this;
• collect information to be able to organize future total counts as good and efficient as possible

In total over more than 2,480,000 waterbirds were counted, including 2,350,000 waders. The results from 2000 confirm the picture from 1997: there is a rather large difference for many species between 1979/1980 and 1997/2000 but in general the numbers in 1997 and 2000 are higher than in 1990-94. given the difficulties observers meet when counting the Banc d'Arguin (high densities, extremely large flocks, risk of exchange between areas) the differences between the 1997 and 2000 results can be considered as small.

The report contains:

• Summary, Area description and methods
• Counting results, and results per group
• Comparison with earlier mid-winter counts
• Density and measurements of West African Bloody Cockles Anadara senilis