“The Tonight Show” host Jimmy Fallon, center, exits the water during the Chicago Polar Plunge, Sunday, March 2, 2014, in Chicago. Fallon joined Chicago Mayor Rahm Emanuel in the event. (Photo by Andrew A. Nelles/AP Photo)

Cormorant masters and boatmen prepare sea cormorants for the nights “Ukai” on July 2, 2014 in Gifu, Japan. In this traditional fishing art “ukai”, a cormorant master called “usho” manages cormorants to capture ayu or sweetfish. The ushos of River Nagara have been the official staff of the Imperial Household Agency of Japan since 1890. Currently six imperial fishermen of Nagara River conduct special fishing to contribute to the Imperial family eight times a year, on top of daily fishing from mid-May to mid-October. (Photo by Chris McGrath/Getty Images)

A chimp motions for Santa to deliver his gift during Lion Country Safari's annual Christmas with the Chimps on Thursday, December 20, 2012. (Photo by Bruce R. Bennett/The Palm Beach Post)

“Asaro from the Eastern Highlands”. The mudmen could not cover their faces with mud because the people of Papua New Guinea thought that the mud from the Asaro river was poisonous. So instead of covering their faces with this alleged poison, they made masks from pebbles that they heated and water from the waterfall, with unusual designs such as long or very short ears either going down to the chin or sticking up at the top, long joined eyebrows attached to the top of the ears, horns and sideways mouths. (Photo and caption by Jimmy Nelson)

Mr. Zhong Hua, of Johns Hopkins University School of Medicine, took this image of the peripheral nerves (those outside of the brain) in an 11.5-day-old mouse embryo, magnified five times. (Photo by Zhong Hua)

Heidi Klum attends the Heidi Klum's 16th Annual Halloween Party sponsored by GSN's Hellevator And SVEDKA Vodka At LAVO New York on October 31, 2015 in New York City. (Photo by Mike Coppola/Getty Images for Heidi Klum)

“The Sumatran tiger (Panthera tigris sumatrae) is a rare tiger subspecies that inhabits the Indonesian island of Sumatra. It was classified as critically endangered by IUCN in 2008 as the population is projected to be 441 to 679 individuals, with no subpopulation having an effective population size larger than 50 individuals, with a declining trend”. – Wikipedia

This photo taken on July 25, 2012 one of 14 preserved bodies of critically-endangered Sumatran tigers seized as members of the Indonesian national police and the special crime unit inspect the scene at a warehouse in Cibubur, south of Jakarta. Indonesian police seized 14 preserved bodies of critically-endangered Sumatran tigers in a raid on a house near Jakarta, a spokesman said on July 19. (Photo by Bay Ismoyo/AFP Photo)

Italian Air Force's aerobatic demonstration team, the Frecce Tricolori leave colourful vapour trails as they fly over the Altare della Patria monument on Republic Day (Festa della Repubblica) in Rome, Italy, 02 Jun 2017. The anniversary marks the founding of the Italian Republic in 1946. (Photo by Massimo Percossi/EPA)