Sheep walk as they are herded to summer pastures in Serra da Estrela, near Seia, Portugal June 27, 2015. In late June, shepherds young and old in the Seia region of central Portugal start guiding sheep, goats and cattle to the Serra da Estrela, the country’s highest mountains, in search of better pastures. There they stay until the end of September. Modern-day shepherds may have mobile phones to keep in touch with family and friends, but their lifestyle has changed little for centuries. The sound of cowbells and the bark of longhaired mastiffs starts early in the morning as the animals – often decorated with traditional woollen balls on their horns – are herded up steep, narrow paths. (Photo by Rafael Marchante/Reuters)

Czech fishermen sort fish during the traditional Carp haul at Lake of Dvoriste near Smrzov village, Czech Republic, 02 November 2015. Carp, the traditional Czech Christmas Eve dinner, is harvested primarly from the region of southern Bohemian lakes. (Photo by Filip Singer/EPA)

A fisherman carries a silver carp during a traditional fish haul at the Horusicky pond near the town of Veseli nad Luznici, Czech Republic, Tuesday, October 24, 2017. Each autumn, Czech fishermen get to serious business of a century-long tradition of catching carp for Christmas markets. Southern Bohemia, where the Horusicky pond is located, with its elaborate network of ponds is at the center of the local carp universe. (Photo by Petr David Josek/AP Photo)

A pheasant stands in snow near Dulverton on January 30, 2012 on Exmoor, England. After unseasonably mild winter weather, some parts of the UK woke to a covering of snow as a cold spell of weather sets in, with forecasters warning temperatures are set to plunge as the week progresses. (Photo by Matt Cardy/Getty Images)

A member of the Community Police of the FUSDEG (United Front for the Security and Development of the State of Guerrero) search for a man, who ran away upon seeing the Community Police approach as they patrolled a street, in the village of Petaquillas, on the outskirts of Chilpancingo, in the Mexican state of Guerrero, February 1, 2015. Approximately 500 members of the Community Police from the FUSDEG took control of the security of the village of Petaquillas on the night of January 30 at the request of the people tired of the actions of organized crime, local media reported. (Photo by Jorge Dan Lopez/Reuters)

Fishermen pull a net containing fish from a pond during the traditional carp haul near the village of Belcice, Czech Republic, October 25, 2016. Carp, the traditional Czech Christmas Eve dinner, is harvested primarly from the region of southern Bohemian lakes. (Photo by David W. Cerny/Reuters)

A participant jumps on vintage skis during a traditional historical ski race in the northern Bohemian town of Smrzovka, Czech Republic, February 20, 2016. (Photo by David W. Cerny/Reuters)

A woman takes part in a traditional horse parade through the streets of San Jose, Costa Rica December 26, 2015. Thousands of riders participated in the parade, which is part of annual year-end festivities. (Photo by Juan Carlos Ulate/Reuters)