Ecoscience: Grazing Ecosystems?From Theory to Practice

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Moreover, like most grazers, cattle have quite specific food preferences-they graze some grass species heavily and others not at all. In cattle-raising areas, the species composition of the forage changes, with those grass species not eaten by cattle becoming increasingly common. But, as we described in our first column on the Serengeti ecosystem (MOTHER N0. 91), the native herbivores partition the available plant species, their diets complementing each other to one degree or another.
Thus, not only are the waterconserving native herbivores better adapted to the semiarid habitat of the African savanna, but they don't degrade it physically or chemically. Cattle, however, parading back and forth to water holes and producing their destructive droppings, have been a major engine of desertification on the continent.

All of these differences led David Hopcraft to conclude that the soundest way to exploit African grasslands is not to graze cattle on them, but to organize ranches to raise and harvest native herbivores. On their 20,000-acre ranch on the Athi Kapiti plains near Nairobi, the Hopcrafts have been putting that theory into practice since 1978.

Exotic Livestock

The ranch is stocked with a variety of grazers and browsers, including antelope, zebras, giraffes, and ostriches. Cattle are being phased out and may one day be replaced by African buffalo. For the present, however, the cattle serve as a valuable "control" for comparing costs and meat yields with those of the native animals.

A great deal of research is being carried out at the ranch. The dynamics of the various populations are carefully tracked, and the food preferences of the different animals are recorded. When we visited the Hopcrafts in early 1984, two veterinarians were at the ranch studying the parasites of harvested animals.
So far, the results of the experiment are exceeding the Hopcrafts' early hopes and expectations. The herds of native herbivores—and the meat yields from them—have been steadily increasing. Simultaneously, the condition of the range has been improving—even though the combined weight (biomass) of cattle and native herbivores has increased by some 35% in the past few years.
Harvesting is efficient and more humane than in a typical slaughterhouse. One night each week, men in Land-Rovers spotlight surplus male animals and dispatch each one instantly with a high-velocity bullet to the brain. The other animals are not distressed. Then each carcass is rapidly processed under the scrutiny of the government inspector.

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