Poaching
Thank you to everyone who replied. We understood initially that the men were out walking, but it was then suggested to us by a senior ex-military source that they had been poaching, hence the camera. They were out in the middle of nowhere on a remote, private, 90,000-acre deer reserve at dusk, having driven 13 miles to get there. The camera was to capture a shot of they bagged a prize, but they allegedly got more than they bargained for.