Agriculture Reference
In-Depth Information
In the 1960s, the American biologist Robert Paine conducted an experiment involving
the removal of a predator species from a seashore environment:
When he removed the main predator, a certain species of star fish, from a pop-
ulation of fifteen observable species, things quickly changed. Within a year the area
was occupied by only eight of the fifteen species. Numbers within the prey species
boomed and in the resulting competition for space, reasoned Paine, those species that
could move left the area; those that could not simply died out.
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Commenting on Paine's experiments, Allan Savory remarks: 'I witnessed a similar dis-
ruption in two much larger communities in Africa', namely the Luangwa valley in Northern
Rhodesia (Zambia) and the lower Zambezi Valley in Southern Rhodesia, where he worked
as a biologist:
Both areas contained large wildlife populations - elephant, buffalo, zebra, more
than a dozen antelope species, hippo, crocodiles and numerous other predators. Des-
pite these numbers, the river banks were stable and well vegetated. People had lived
in these areas since time immemorial in clusters of huts away from the main rivers,
because of the mosquitoes and wet season flooding. Near their huts they kept gar-
dens that they protected from elephants and other raiders by beating drums throughout
much of the night or firing muzzle-loading guns to frighten them off. The people
hunted and trapped animals throughout the year as well.
But the governments of both countries wanted to make these areas national parks.
It would not do to have all this hunting going on, and all the drum beating, singing
and general disturbance, so the government removed the people. Like Paine, we, in
effect, removed the starfish. But in our case we put a different type of starfish back in.
We replaced drum-beating, gun-firing, gardening and farming people with ecologists,
naturalists, and tourists, under strict control to ensure they did not disturb the animals
or vegetation.
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The result was a change in grazing behaviour by many of the animal populations, and a
rapid deterioration in environmental quality. 'Within a few decades, miles of riverbank in
both valleys were devoid of reeds, and most other vegetation. With nothing but the change
of behaviour of one species these areas became terribly impoverished and are still deterior-
ating as I write.'
