According to an article on BBC News, huge flocks of red-beaked quelas have destroyed up to 70% of the crops in northern Nigeria. They have been driven there in a search for food from neighboring Niger, which has just experienced a drought and a plague of locusts. The poor people of Niger have been thrown into yet another famine and children are once again starving.The people of Niger, the quelas, and the locusts are all caught up in a natural population boom-and-bust cycle. Many of us have learned to associate the word natural with goodness, but famine can hardly be described as good when people are involved. Part of the answer in this case will be to dump hundreds of tons of poison on both the locusts and birds.
Most human societies today have escaped famine because they have developed diversified food portfolios and have a population-growth rate that does not outpace economic growth. They have a measure of economic diversity and an adequate number of trading partners in distant places. For example, although it would cause great financial hardship, a major crop failure in Washington State would not cause a famine anywhere. The disaster in Niger is primarily the result of three variables: weather, population growth (PDF), and poverty. Poverty and population growth are inextricably linked: Shrinking one tends to shrink the other.
Niger, Israel, and Saudi Arabia are arbitrary boundaries with names (countries) located in hot, dry parts of the planet. Two of the three are relatively famine-resistant because they have many trading partners. Saudi Arabia trades oil and Israel trades products and services. Note that this concept is somewhat at odds with the “buy local” movement. Part of the problem in Niger is that they buy too much locally. They are eating what they grow and when crops fail, they have nothing to eat.