A visitor holds up her toy bunny to the aquarium glass in front of Aurora the Russian polar bear at the Sao Paulo Aquarium in Sao Paulo, Brazil, Thursday, April 16, 2015. (Photo by Andre Penner/AP Photo)

Children pat an elephant at the mobile Diva circus in the town of Molodechno, some 70 kilometers northwest of Minsk on September 3, 2015. (Photo by Sergei Gapon/AFP Photo)

A participant in the Crazy Races extreme sports game competes in the cross-country obstacle race in Ufa, Russia on September 21, 2015. (Photo by TASS/Barcroft Media)

Olaf Niess catches swans on the river Alster near the town hall in Hamburg, Germany, 17 November 2015. The Alster swans are moving to their ice-free winter quarters on the Eppendorf Muehlenteich millpond until spring. (Photo by Bodo Marks/EPA)

Costumed revellers walk in the streets of Lucerne during the annual carnival parade on Rose Monday March 3, 2014. (Photo by Sigi Tischler/AP Photo/Keystone)

Bronze whaler shark (Carcharhinus brachyurus), caught in traditional seine net and released by fisherman, Muizenberg beach, Cape Town, South Africa on October 11, 2016. Action shots have captured fishermen trying to free a potentially deadly Bronze Whaler shark who was caught in their nets. The incredible images show the eight-foot-long 500-pound predator lunging its mouth towards the fishermen who are desperately trying to pull it back into the safety of the sea by its tail. Eventually they succeeded. (Photo by Chris and Monique Fallows/NPL)

Two cocks are trained for a fight in a village in Nakhon Sawan province, Thailand January 10, 2017. (Photo by Chaiwat Subprasom/Reuters)