An alpaca chewing a leaf is pictured on November 18, 2014 in the zoo of Frankfurt am Main, Germany. (Photo by Frank Rumpenhorst/AFP Photo/DPA)

Against the scorching sun, a hungry jackal chases a flock of birds looking for a quick morning snack. Taken in South Africa's Kgalagadi Transfrontier National Park, these images capture the moment a lone hunter tries, and then succeeds, in his pursuit. (Photo by John Mullineux/Solent News)

Vladimir Putin shows a hold to a young judo wrestler at the Regional Judo Center at the Arena Sports Complex in the Siberian city of Kemerovo on January 24, 2012, during his visit to the region. Putin is known for his passion for judo, in which he has a black belt. (Photo by AFP Photo/STR)

Mexicans dressed as French soldiers carry handcrafted guns, ahead of a reenactment of the battle of Puebla between Zacapoaxtla Indians and the French army during Cinco de Mayo celebrations in Mexico City, Tuesday, May 5, 2015. Monsalvo said he has been portraying Napoleon III in the annual neighborhood event for 28 years. Cinco de Mayo commemorates the victory of an ill-equipped Mexican army over French troops in Puebla on May 5, 1862. (Photo by Rebecca Blackwell/AP Photo)

Rick Sorenson, owner of the Rio Ramaza Marina, wades in the Sacramento River after securing an old paddlewheel boat on his property as the river makes its way up the levee on Garden Highway in Sacramento, Calif., Monday, January 9, 2017. (Photo by Hector Amezcua/The Sacramento Bee via AP Photo)

In this February 19, 2017 photo, a couple dances during the “If you don't give me....then you lend me” Carnival street party on Ipanema beach, in Rio de Janeiro, Brazil. The typical view of Carnival in Brazil is anything goes, with no headdress too big, no outfit too small, no song too ribald, but this year some organizers of the world's best known party are drawing the line at lyrics that are sexist, homophobic or racist. (Photo by Silvia Izquierdo/AP Photo)

The possible surface of TRAPPIST-1f, one of seven newly discovered planets in the TRAPPIST-1 system that scientists using the Spitzer Space Telescope and ground based telescopes have discovered. (Photo by Reuters/NASA/JPL-Caltech)

A man cries as he carries his daughter while walking from an Islamic State-controlled part of Mosul towards Iraqi special forces soldiers during a battle in Mosul, Iraq March 4, 2017. Reuters Photographer Goran Tomasevic: “Both screaming in terror, a father and the young daughter he cradled in his arm fled through the rubble-strewn streets of Wadi Hajar, transformed in a flash into a battleground between Islamic State fighters and Iraqi special forces. They and their neighbours – some wearing rubber sandals, some barefoot – were running from an IS counter-attack in this part of Mosul, dodging gunfire as the militants closed in”. (Photo by Goran Tomasevic/Reuters)