Free-ranging goats have a reputation for overgrazing, which happens when their numbers surpass the capacity of the land to support them. Gully erosion results when they destroy the native vegetation and compact the soil with their sharp hooves. Several characteristics of goats favor abuse of the plant cover. A mobile upper lip permits them to graze as close to the ground as sheep at the same time that their browsing capacities exceed those of their fleecy cousins. Thorny plants with small leaves are no hindrance to goats. If browse is in short supply, they will defoliate entire bushes. Goats browse to the height they can reach when standing on their hind legs. They will also forage on leaves by climbing into low trees. With their sharp hooves, they paw away soil to obtain roots and subterranean stems. Allowed to roam, goats can occupy considerable space. On the average, they move 9.7 kilometers (km) per day, compared with 6.1 km for sheep and 53 km for cattle (Huston 1978).
It is true that goats have contributed to desertification, but they often get more blame than they deserve. The process begins when first cattle, and then sheep, deteriorate the range, after which the invading brush is suitable only for goats, which can survive and reproduce in such environments. Thus, goats become the last alternative on eroded lands and are often seen as totally responsible for them.
Ultimately, however, destruction of vegetation by goats is a human management failure. An arid hillside combined with excessive numbers of goats will almost always mean harm for that environment. Human unwillingness to control goat density at a desired maximum, or to restrict the animals’ mobility, has determined the land-use history of many areas. Humans have frequently introduced goats to islands and then left them to their own devices. Without predators, feral goat populations have exploded and destroyed ecological balances; the histories of many islands, from San Clemente, California, to St. Helena, involve goat stories.
The Mediterranean Plan, funded by the Food and Agriculture Organization of the United Nations (FAO) in the 1950s, was the first concerted international effort to deal with such problems. Impoverishment of the Mediterranean region was attributed to the environmental degradation brought on by overgrazing. We know that some of this process was begun in ancient times because classical authors discussed the goat problem two millennia earlier (Hughes 1994). The Mediterranean localities most heavily dependent on goat products were those with the most serious erosion. In the 1940s, Cyprus, which derived one-third of its milk, two-fifths of its cheese, one-fourth of its meat, and four-fifths of its leather from goats (Thirgood 1987), was deforested because of excessive goat browsing. Vegetation flourishes in the Mediterranean region where goats and sheep are restricted. In northern Morocco, the barren slopes that are grazed by goats contrast with ungrazed enclosures that maintain a luxuriant tree cover.
Daniel W Gade
World History
