Final answer:
Pastoralists aim to maximize herd size due to its direct correlation with wealth, social status, and the sustainability of their livelihood, which depends on the continual movement to fresh pastures. However, the pressure to increase herd size can contribute to the tragedy of the commons, leading to long-term risks for both the environment and the pastoralists' way of life.
Step-by-step explanation:
Pastoralists like to maximize herd size for several reasons. Primarily, the size of a family's herds is a measure of wealth and social status within their community. Moreover, the animals serve as a vital source of nutrition and resources, such as milk, meat and wool and are essential for the pastoralists' sustainable lifestyle as they often live in marginal lands that require regular movement to fresh pastures.
The strategy of rotating herds helps control the environmental impact, making pastoralism a sustainable way of life despite challenges like climate change and competition for grazing lands. In the context of the tragedy of the commons, each herdsman seeks to maximize their gain by adding more cattle to their shared resources, leading to an inevitable depletion of the commons without a limit to herd growth. This systemic issue often compels further expansion of herd size as a short-term rational strategy for individual gain, risking long-term sustainability. With the impacts of climate change being increasingly felt such as erratic rainfalls, temperature rises and prolonged droughts pastoralists are more challenged in maintaining their herd sizes due to environmental pressures, malnutrition and poor market prices affecting their livelihoods.