The three livestock types included in the graphs are cattle, sheep, and goats. The data shows that in general the overall number of grazing animals increased in this time period. Globally the cattle and goat numbers grew while sheep numbers stayed relatively stable. In Nigeria, the goat and sheep numbers grew while cattle stayed relatively stable.

2008 — bulk of grazing herd globally was cattle at almost 1,400 million head (of a total grazing herd about 3,200 million head). But in Nigeria it was goats at almost 55 million head (of a total grazing herd almost 105 million head).

1961 — bulk of grazing herd globally was sheep at 994 million head; the next largest herd was cattle at 942 million. But in Nigeria it was cattle at 6 million head; the next largest herd was sheep at 1 million.

Here is one example of how you calculate this:

1961 world sheep count = 994 million

2008 world sheep count = 1,086 million

% change in sheep numbers = [(1,086-994) / 994] x 100 = 9.25%

Both worldwide as well as in Nigeria, the biggest change was in goat numbers that increased by 147.6% and 8,866% repectively.

Changes in goat populations may indicate that grassland quality is poor and there is not suitable forage for cattle or sheep. This grassland degradation might be a result of overuse of the land by underprivileged individuals in this developing country. Individuals with few options for earning a living or providing for their family may over-exploit their immediate surroundings just to survive (in this case increasing the size of goat herds on deteriorating lands). It is difficult to tell an impoverished landowner in Nigeria to resist increasing the size of his goat herd and instead preserve the soil, when goat herding is the only way he can feed his family.

The consequences of this could be even more damage to the land (and water in the area), reducing the land’s ability to support the animals. But as human and goat populations grow in Nigeria, more soil erodes and herders compete for even smaller amounts of suitable land. If Nigeria’s human population and livestock herds continue growing as they are today, the associated land degradation will eventually undermine herding and the wellbeing of those who depend on this way of life.

Social traps, or decisions by individuals or groups that seem good at the time and produce a short-term benefit, but hurt society in the long run, are clearly evidenced in the increasing size of the goat herds. Herders overgraze with the idea that “If I don’t take it, someone else will” (tragedy of the commons) thus increasing the risk of desertification. And switching to goats rather than cattle simply exacerbates this problem by reinforcing a bad decision (sliding reinforce trap), as it initially seems like a good idea but in reality is simply delaying the effects of overgrazing (the time delay trap) until the land is so badly damaged that recovery may not be possible.

Some ways that we could avoid these traps are through adoption of new patterns of behavior that could include reducing meat consumption, reducing population growth, changing grazing and other farming practices to sustainable ones that reduce soil erosion and over the long term raise productivity, and balancing the size of livestock herds with nature’s capacity for regeneration.