If it wasn’t for a hidden herd in the deepest reaches of this National Park, bison would have been wiped out in the late 1800s. Today, thousands of them thrive.

A bison feeds in a forest during winter in Nalibokskaya Forest Reserve near the village of Rum, some 80 km (50 miles) west of Minsk, January 11, 2013. Several dozens bisons live in this reserve ...