Read this paragraph from "How Water Loss Affects Biodiversity." “When a region experiences a significant drought, many animals may die from lack of water and food. […] If tourism declines due to high wildlife casualties, then the locals who depend on income from tourism will lose their livelihood. People may then turn to farming to earn money, but crops require water to grow. This can place further strain on the water supply and worsen the original problem of the drought.”

What event can cause many animals to die from lack of water and food?