Southern Slovenian forests, December 2011. The trees have shed their leaves, and the air grows increasingly sharp. Among the bare trunks, a young wolf scents the air; his restless eyes scan the surroundings, his senses tighten at every rustle: it is time to leave. His brothers and sisters have already done so, or are about to. He is two years old, and instinct tells him he cannot spend another winter in the place where he was born.

So he sets off on what, in wolves, is known as dispersal—the search for a new territory where he might settle and perhaps find a mate, and, if he is lucky, start a new family, a pack. Despite the many risks, the young wolf begins his journey on December 19, 2011. The certainty of this date is ensured by the fact that the wolf belongs to a pack monitored by biologists from the University of Ljubljana, who had managed a few months earlier to fit him with a radio collar—an instrument capable of transmitting the animal’s position and movements.