The autumn rut was in full swing. This mature bull had gathered a small harem of cows, but the job was far from over. As the cows fed their way through the meadow, a bugle echoed from somewhere beyond the dark willows. His response was immediate. He raised his head and answered with a powerful bugle of his own. It wasn't simply a call drifting across the valley. It was a warning to an unseen rival that these cows were already under his protection. During the rut, a herd bull uses his bugle to keep his cows together while announcing his dominance to competing bulls. For several minutes I watched him move with his harem, constantly listening, watching, and reminding the unseen challenger that he wasn't willing to surrender what he had worked so hard to protect.