The study was conducted near Nyae Nyae pan, which is located 20 km south of the settlement of Tsumkwe, Bushmanland, in northeastern Namibia. Nyae Nyae is the largest of a group of 13 alkaline pans that normally are dry except during periods of heavy rainfall. Grassy marshes (dominated by Diplachne spp.)  surrounding the unvegetated pans are limited in size, and their period of inundation is highly variable both within and between years (Hines 1993).