MADRID, SPAIN - NOVEMBER 02:  Sheep are mustered through Puerta del Sol square to promote the conservation of the ancient paths of migration (moving flocks from winter to summer pastures) dating back some 8,000 years on November 2, 2014 in Madrid, Spain. Two thousand sheep passed through the city centre joined by shepherds, marking the annual livestock migration festival which has taken place in the Spanish capital since 1994.  (Photo by Denis Doyle/Getty Images)