COSTS OF OVERSTOCKING ON CATTLE AND WILDLIFE RANCHES IN ZIMBABWE

In African semi-arid savannas livestock production frequently dominate s human activity, but it has been claimed that wildlife ranching can b e more profitable than extensive beef production. Traditional accounti ng methods generally exclude the biological costs of stocking effects on rangeland productivity. This paper presents a framework for evaluat ing overstocking effects on the financial profits (based on market pri ces) and economic profits (estimated from the opportunity costs of inp uts and outputs) of alternative range-based animal production systems. The method was applied to 50 commercial cattle, wildlife, and mixed r anches in the Zimbabwe Midlands using 1989/90 data. Level of overstock ing was estimated from positive differences between grazer stocking ra te and rangeland carrying capacity, which was predicted from long-term mean annual rainfall. Since it is generally impossible to accurately quantify stocking effects on rangeland productivity, and thus to confi dently evaluate overstocking costs, values ranging from Z$0.00 to Z$0. 50 kg(-1) ha(-1) overstocking were used. The resulting range of costs were subtracted from financial and economic profits. Cattle ranches we re significantly overstocked while mixed and wildlife ranches were not . Thus cattle ranch profits decreased more rapidly with increasing sim ulated overstocking cost. In other words, with increasing sensitivity to overstocking, wildlife and mixed ranches had a higher probability o f remaining financially and economically profitable than did cattle ra nches.