Behaviour: Mammals – The Charge by Eric Pierre (France)Eric had been tracking Arctic wolves on Victoria Island, Canada, when his guide spotted a herd of muskoxen 3 miles (5km) away. Approaching, Eric could see that the herd was nervous, probably because wolves were also on its trail. He made a detour and stopped about half a mile away upwind. Suddenly, he realised that the herd was now running towards them, oblivious of them. "I’ve seen muskoxen run away," says Eric. "I’ve seen them react to a threat by forming a circle, and I’ve even seen a male charge. But I’ve never seen a herd spread out into a charging line like this. I could hear the thundering of their hooves. It was one of those situations where it really mattered that I made the right choice between technical accuracy, aesthetics and security."