of open grassland has been observed to have a positive relationship with herd size. Home ranges remain remarkably constant and stable year after year. The only documentation of the actual home range boundaries of these animals is relatively recent, so only time will tell how these boundaries remain over large lengths of time; however, studies have shown almost no movement in range boundaries from one year to the next. Although the area included in a home range is relatively constant over time, the preferences in regard to what part of the range is most used shift with the seasons. From March until August, African forest buffalo spend most of their time in the forest, while from September through February, they favor the savannas and marshes. African forest buffalo arrange themselves into herds, which help in defense against predators; however, they are not immune to assault. Among predators, the African leopard is the most common, but is generally only a threat to young buffaloes and will feast on them only when they have the opportunity. The Nile crocodile is the only predator which is capable of killing an adult buffalo. Social behavior African forest buffalo have relatively small herds compared to the well-studied Cape buffalo. Cape buffalo can have herds of over 1,000 members; however, African forest buffalo stay in much smaller groups—as small as three and rarely over 30. If African forest buffalo are in a large group, they spend more time grazing, since there is less need to devote time to alert behavior. A herd of African forest buffalo typically consists of one or occasionally two bulls and a harem of adult females, juveniles and young calves. Unlike Cape buffalo bulls, African forest buffalo bulls remain with the herd continually, year round. On the other hand, Cape buffalo bulls stay in bachelor herds until the wet season, when young bulls join the females, mate, help protect the young calves and then leave. Animals usually remain in the same herd for their entire lives. Herd-switching in cows has been observed; however, this is not a common occurrence. Herds can split into two groups for a short period of time before merging back together. African forest buffalo are relatively unaffected by seasonal cycles. However, in the wet season, herds are more spread out in the forest and these animals tend to use resting places based on sand during the wet season,