National Geographic : 1990 Dec
Cattle, wild buffalo, and the tsetsefly have engaged in a long standing dance of death and disease in the Oka vango Delta. Cattle near Maun are driven along the so-called Buffalo Fence built in 1982 (left), one of many vet erinary cordonfences erected to controlfoot and-mouth disease. Stretchingfor 150 miles, thisfence keeps cattle out of the delta (opposite, top) and keeps in wild buffalo, suspected carri ers of the disease. Infestationby the tsetse originally kept cat tle from penetratingthe delta. However, in the 1960s Botswana'sgov ernment declared chemi cal war on this pest, beginning with ground spraying.More success ful aerialspraying in the 1970s and '80s has resulted in near eradica tion of the tsetse fly, but ground sprayersstill tar get isolated areasof infestation (opposite, bottom). With the tsetsefly under control and no majoroutbreaks offoot and-mouth disease,pres sure is mounting to open up parts of the delta to cattlegrazing.