Books/documentaries about horse behavior in the wild
There's only one documentary that I know of that actually addresses wild horse instinct and behavior, and that's the Cloud series. The only books I can find on behavior are how-to books or books that describe interaction between horse and human. I also read The Nature of Horses which described how horses evolved and survived and measured their intelligence, but wasn't specific on behavior. I want to research horse and horse interaction, preferably in the wild with no human interaction because I believe that's the best way to understand horse psychology and social interaction.
Does anyone know of any books or documentaries that focus on horse and horse interaction, or how horses interact in the wild? Someday when I'm older and richer, I'm going to make frequent trips around America to study and document wild horses, I'm planning on writing a few books on it when I do.