Bob Loos of Global Flyway Network reports:
Curious to understand more about oversummering waders in West Africa, we set out to count our study areas in Parc National Banc d’Arguin, Mauritania.

During counts between 9 and 15 July 2017, carried out by the GFN team consisting of Ahmed Medou, Ahmed Amarajeyat, Mohamed Camara, Jan van Dijk and Bob Loos, a total of almost 65,000 birds were counted at six sites near Iwik, Mauritania (see map).
During high tides, the islands of Arel, Nair and Zira were counted, together with the coast of Ebelk d’Aiznaya and part of the Baie d’Aoutief.
The highest numbers were recorded for Flamingo (13,800), Curlew Sandpiper (12,614!), Dunlin (7,758) and Bar-tailed Godwit (5,046). Surprisingly, only 1,357 Red Knots were counted.

The last census of oversummering waders in Banc d’Arguin dates back to June 1988 when the entire area was counted between 8 June and 3 July during a WIWO expedition.
Comparison of the results with 1988 is not yet possible because the results per counting area from 1988 are not yet available. However we know that in June 1988 on Arel 2,400 Sanderlings and 1,400 Curlew Sandpipers were counted. We arrived at 2,450 Sanderling, and a spectacular number of more than 10,000 Curlew Sandpipers!
As expected, the majority of the oversummering waders were “young” birds, born in the previous summer and now in their second calendar year.
We also collected more than 300 colour-ring re-sightings from, among others, Red Knots, Bar-tailed Godwits, Curlew Sandpipers, Whimbrels and Spoonbills (both the local breeding birds of the subspecies balsacii and birds from the Dutch breeding population that decided to oversummer). More about those birds next time!
For curious readers we included the count data below.