Both sources explore the history and current status of mustangs, focusing on their origins as descendants of Spanish horses, their spread across North America, and the significant impact of human actions on their populations. The sources detail population fluctuations due to warfare, government policies, and land use conflicts. The ongoing debate surrounding mustangs' ecological role and their management by the Bureau of Land Management is also highlighted, emphasizing the complexities of balancing conservation with competing land uses. One source provides a detailed historical account, while the other offers a more concise overview of human impact.