What does a wild horse's body language tell a trainer?

Reading a wild horse's body language accurately is the foundational skill of wild horse training because the horse's body communicates its emotional state, its assessment of the trainer as a threat, its level of acceptance of the current situation, and its readiness to advance to the next stage of the interaction continuously and specifically — and the trainer who can read this communication can calibrate every advance and retreat to exactly the threshold where learning is possible without triggering the flight response that shuts down learning entirely. The ears are the most immediately readable signal: both ears locked forward and upward with a fixed stare indicate a horse that has identified a potential threat and is assessing it; one ear toward the trainer and one scanning the environment indicates divided attention and partial acceptance; both ears softened and mobile indicate a horse that has moved out of high alert into a more receptive state. The tension through the body communicates arousal level — a horse with a raised head, tight muscles through the neck and shoulder, and a tail clamped down or raised is in a high-arousal fear state; a horse with a lowered head, loose muscles, and a relaxed tail is in a low-arousal receptive state. The nostrils communicate through their shape and movement — wide, flared nostrils gathering scent indicate active threat assessment; soft, relaxed nostrils indicate the horse is not in active alert mode. Licking and chewing, the opening and closing of the mouth in a non-eating context, is one of the most significant signals for trainers because it indicates the horse is processing and accepting rather than resisting — Monty Roberts and other join-up practitioners specifically watch for licking and chewing as a signal that the horse's nervous system has shifted from a defensive to a receptive state. The dropping of the head, particularly below the withers, indicates a horse releasing tension and moving toward acceptance.