Humboldt Penguins swim in their pool as a keeper looks on through a spherical window during the annual stocktake press preview at London Zoo in Regents Park in London Monday, January 4, 2016. A requirement of ZSL London Zoo's license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where it's used to manage the worldwide breeding programmes for endangered animals. (Photo by Alastair Grant/AP Photo)

Artist Jason deCaires Taylor’s Museo Atlantico, off Lanzarote, is peopled with concrete casts of refugees and people taking selfies. Drowned world: welcome to Europe’s first undersea sculpture museum. Here: The Raft of Lampedusa, Taylor’s modern-day concrete echo of Géricault’s The Raft of the Medusa. The work has particular significance given the huge movement of refugees across the sea to Europe – and the frequent fatalities that result. (Photo by Jason deCaires Taylor)

Beloni (34) gives a bath to his son, 6, on a small street in the neighborhood of Cite Vincent, on March 21, 2016 in the commune of Cite Soleil in the Haitian capital Port-au-Prince. World Water Day, marked on March 22, 2016, is an international observance to learn more about water related issues and to take action for sustainable management of freshwater resources. (Photo by Hector Retamal/AFP Photo)

Chinese conglomerate Tiens Group employers take photos while waiting to be served Paella in Madrid, Spain, Friday, May 6, 2016. The billionaire founder of Chinese conglomerate Tiens Group is treating 3,000 of his best salespeople to a traditional Spanish paella meal in a free Madrid trip that also includes a bullfight and a tour of King Felipe VI's Royal Palace. The smiling salespeople washed down their heaping plates of paella with sangria Friday at a mass spread of picnic tables in a riverside park during the event footed by Li Jinyuan and organized by China's U Tour travel company. (Photo by Paul White/AP Photo)

In this undated photo made available by journal Nature on January 15, 2014, a northern bald ibis (Geronticus eremita) flies in Tuscany, Italy. A new study released Wednesday, January 15, 2014 says the birds choreograph the flapping of their wings, getting a boost from an updraft of air in the wake of the flapping wings by flying behind the first bird and off to the side. When a flock of birds take advantage of these aerodynamics, they form a V. (Photo by Markus Unsöld/AP Photo)

Vancouver B.C. April 20, 2014 Big Day to celebrate as thousand gathered in front of Vancouver Art Gallery to take part in the 420 Marijuana smoke in here in Vancouver on April 20, 2014. Here lots of free “joints” ready for the big moment. (Photo by Mark van Manen/PNG Staff Photographer/Ian Austin Province News/Vancouver Sun News & Web stories)

A participant takes part in the Bristol Park and Slide project, an interactive temporary installation by artist Luke Jerram set up in Park Street in the centre of Bristol, southwest England on May 4, 2014. Over 95,000 people applied for just 360 tickets to slide on inflatable lilos down a lubricated water slide in a town centre street. (Photo by Leon Neal/AFP Photo)

A US soccer fan cheers during the FIFA World Cup 2014 group A preliminary round match between Brazil and Croatia at the FIFA Fan Fest in Copacabana, Rio de Janeiro, Brazil, 12 June 2014. Brazil won 3-1. The FIFA World Cup 2014 will take place in Brazil from 12 June to 13 July 2014. (Photo by Abedin Taherkenareh/EPA)