A protester dressed as a clown holds an umbrella over a Swiss police officer on a motorbike during a May Day demonstration in Zurich, Switzerland on May 1, 2017. (Photo by Arnd Wiegmann/Reuters)

Russian servicewomen march at Red Square during the Victory Day military parade in Moscow on May 9, 2017. Russia marks the 72nd anniversary of the Soviet Union's victory over Nazi Germany in World War Two. (Photo by Kirill Kudryavtsev/AFP Photo)

A woman receives a bouquet made of vegetables and flowers, priced at 238RMB, from a delivery staff of a florist outside an office building on Valentine's Day in Beijing, China, February 14, 2017. (Photo by Jason Lee/Reuters)

Mary, 8-months-old female orphan elephant, drinks milk at Winga Baw Elephant Conservation Camp during the ceremony to mark World Elephant Day at Bago Region, Myanmar, 12 August 2017. Winga Baw Elephant Conservation Camp, 34-hectare former timber camp for logs located in Bago Region, currently has 14 elephants and was opened for recreation for locals as well as for tourists. World Elephant Day is marked annually on 12 August. (Photo by Lynn Bo Bo/EPA/EFE)

Costume actors to wait before the show at “Chian Tourism Day” Inauguration Ceremony in Ninghai Zhejiang Province on May 19, 2011 in Ninghai, China. Various activities in local famous historic sites are being held to mark the day “China Tourism Day” on May 19. (Photo by Lintao Zhang/Getty Images)

Ten day old male Gorilla “Fataki” clings to his mother “Frala” during his media debut at Taronga Zoo June 4, 2003 in Sydney, Australia. Fataki was born on May 24, 2003 and was the fourth Gorilla to be born at Taronga Zoo since the opening of the Gorilla Forest in 1997. (Photo by Chris McGrath/Getty Images)

Students of JSS Dutse Alhaji participate in a cultural dance performance during celebrations to commemorate Nigeria's 55th Independence Day in Abuja, Nigeria, October 1, 2015. (Photo by Afolabi Sotunde/Reuters)

Couples (L-R) Chaiyut Phuangphoeksuk and Prontathourn Pronnapatthun, and Nichapatr Koomsombut and Pirat Rungthongoran run from sheep during their wedding ceremony at a resort in Ratchaburi province February 13, 2015. Three Thai couples took part in the wedding ceremony arranged by a resort themed around fun activities ahead of Valentine's Day. (Photo by Athit Perawongmetha/Reuters)