A herder is seen amidst antlers while working with reindeer at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. People, including local herders and members of their families, gathered at the site to mark Reindeer Day, a professional holiday of reindeer breeding workers, which is celebrated annually on August 2 in the region. (Photo by Sergei Karpukhin/Reuters)

An aerial view shows Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

Tents are set up at a reindeer camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

Sons of local herders sit near reindeer at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

A helicopter flies above a reindeer camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

Sons of local herders play with a ball near reindeer at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

A boy, one of the children of local herders, throws lasso at a reindeer camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

A boy, one of the children of local herders, stands near a herd of reindeer at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

A boy, one of the children of local herders, throws lasso at a reindeer camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

A herder works with reindeer at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

A herder is seen amidst antlers while working with reindeer at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

Reindeer gather at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

People dance during a ceremony to mark Reindeer Day at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

Herders work with reindeer at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

Reindeer gather at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

Herders are seen amidst antlers while working with reindeer at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

A view shows reindeer at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

Herders work with reindeer at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

A helicopter flies above a reindeer camping ground as people take cover, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

Children of local herders gather at a reindeer camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

Tents are set up at a reindeer camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)

A Nenets man rides a reindeer sledge during a competition to mark Reindeer Day at a camping ground, some 200 km (124 miles) northeast of Naryan-Mar, the administrative centre of Nenets Autonomous Area, far northern Russia, August 2, 2015. (Photo by Sergei Karpukhin/Reuters)