East Africa is not a tropical rainforest climate. Although it is close to the seaside, due to the influence of monsoon, some places are often dry (sometimes the wind blows from the inland to the seaside, and this wind and water vapor rarely form rainfall), so the rain is not enough; At the same time, Africa's agricultural technology is relatively backward in general, and its grain output is not high; Coupled with some wars, some countries will have famine.
More commonly, it refers to many national parks in Africa, where animals have to move to other places to find food and water during the dry season. Buffalo and wildebeest migrate because they don't eat or drink in the dry season.