Pastoralism refers to a livelihood approach that makes use of domesticated animals
- for example, sheep, goats, cattle, camels
- to provide a variety of products such as milk, skins, cash and occasionally, meat (Figure 2.3). Pastoralism evolved predominantly in Asian and African arid lands where most livestock were domesticated. Domestication is thought to have been undertaken by sedentary farmers rather than hunters, as they would have had the capacity to corral animals for extended periods (Channell 1999a). Camels, the only livestock domesticated in hyper-arid deserts, are physiologically able to withstand desert conditions as they tolerate elevated body temperatures, are able to minimise water loss and reduce heat gain from the environment (Halpern 1999; Figure 2.4). They are able to tolerate water loss of more than 25 per cent of their body weight and can replace this within three minutes. They are without question well-suited to the desert environment and were responsible for most trans-desert trade before the advent of motor vehicles. Llama and alpaca are close relatives of Old World camels, and were domesticated to serve some of the same uses in the arid highlands of the Andes. Nevertheless, all mammals require water at frequent intervals, and in deserts this means herders must take livestock to temporary or permanent water holes, perennial or ephemeral streams and, in many instances, spend long hours lifting limited groundwater to the surface, often from great depths.

Other domestic animals are less well-adapted to deserts physiologically, but are nevertheless important for desert pastoralists. Sheep and goats represent the smaller, more tradable and expendable animals in southern African deserts, while cattle have greater associated prestige. Cattle (zebu in their humps), camels (in their humps) and sheep (in their tails) have concentrated fat deposits that store energy to carry them through times of limited pasture, but which do not hinder temperature regulation.

Based on different combinations of domestic animals, all forms of pastoralism incorporate an element of hunting and gathering, and many incorporate crop production as well. Most well-known are the nomads, with no permanent home base (Box 2.2). Entire families or groups move together with the herds. This is not a random movement, but usually follows fixed routes with careful scheduling based on rainfall and the presence of other herders (Flegg 1993, Pailes 1999, Smith 1994). Transhumance is the term given to livelihoods that include permanent villages and horticulture, augmented by seasonal movements of part of the group, often the men, with livestock to good grazing areas. This may develop into a well-structured system where nearby grazing is protected and distant grazing used as conditions allow (Jacobsohn 1994, Pailes 1999). An important component of pastoralism is the presence of mobile merchants who, assuming many similar livelihood traits, support movement of products like salt, spices, grains, and necessities of life (Flegg 1993). The increasing complexity of interactions as pastoralism developed meant that individual families or small groups of huntergatherers changed to include more defined levels of organisation as an important component of living in and using ephemeral pastures and other resources of the desert landscape.

Mobility is a key to successful pastoralism in deserts as much as it is important for huntergatherers. Early herders followed rainfall and the variable grasslands that would appear in some areas in some years (Henschel and others 2005, Kinahan 1991). In some instances early herders harvested and ground natural grass grains as part of their resource base (Sandelowsky 1974). Nevertheless, there were distinct differences between strategies used to support differing livelihoods, as evidenced in the Namib Desert. While hunter-gatherers used reliable waterholes as periodic dry season gathering points, pastoralists with their herds spent dry periods in small dispersed camps. After good rains, pastoralists and their herds would aggregate wherever patchy rain provided good grazing (Kinahan 2005).

The Himba, the "ochre people of the dry riverbeds", are well known and admired for their herding prowess, particularly by those living in higher rainfall areas (Jacobsohn 1994; Figure 2.5). With the advent of rain, they move westward to annual pastures of the desert margins, preserving more permanent desert springs and their surrounding vegetation for the late dry season. For such a system to work, social relations and organisation are very important to the entire group. This is encapsulated in their saying: "don't start your farming with livestock, start it with people". A system where inheritance through females relates to material wealth, while residential units and authority are inherited through males, serves to strengthen the needed social organisation. Contrary to many declining pastoral groups in arid southern Africa today, older people make sure that younger herders have full access to all available knowledge for successful use of the desert landscape.

For many centuries, pastoralism has been an important livelihood in the deserts of Asia, such as the Gobi (Box 2.3). Pastoralists manage the greatest proportion of desert lands, for subsistence or for profit, but alternatives ranging from hunting to tourism on desert pastures are emerging. On the other hand, increasing population, changing politics, enhanced educational opportunities and globalisation are all influencing pastoralists of the desert realm.

Today, pastoralists do not necessarily live in deserts but continue to herd their animals there to provide valuable products for urban consumption. Camels are being replaced by cattle with their better market value, and four-wheel drive vehicles provide transport (Smith 1994). It is a way of life that is rapidly changing, but nomads are still considered to be the most efficient producers of meat in deserts. Because of the large areas they use, they are profoundly affected by changes in politics and the environment, and their future is variable and unpredictable (Marx 1994).