A curious leopard cub toys with a camera at MalaMala Game Reserve in Mpumalanga Province, South Africa. (Photo by Barcroft Media)

Male orangutan Percy is reflected in the Sekonyer River as he reaches over to try and touch a wooden klotok boat carrying crew and tourists, in Tanjung Puting National Park, in Kalimantan (Indonesian Borneo), Indonesia, September 4, 2013. Percy is a son, born and living in the wild, of a female orangutan named Princess, a freed former captive orangutan that anthropologist Dr Birute Galdikas rescued, rehabilitated and returned to the wild. (Photo by Barbara Walton/EPA)

In this July 10, 2014 photo, Chris Minore, of Orange, Conn., performs the under chop technique at the Adirondack Woodsmen's School at Paul Smith's College in Paul Smiths, N.Y. Eighteen young students in matching gray sports shirts took part recently in a weeklong crash course on old-school lumberjack skills such as sawing, chopping, ax throwing, log boom running and pole climbing. (Photo by Mike Groll/AP Photo)

Completion is near on Monaco's tallest skyscraper ever, and its first new one since the 1980s. Fueled by a luxury-housing boom in the tax-haven nation, the Odeon Tower's so-called Sky Penthouse is expected to sell for more than any other apartment in the world has ever sold before. Photo: The five-story Sky Penthouse is expected to be complete in September 2015. The water slide extends from a dance floor in the residence down to a private infinity pool. (Photo by Tour Odeon)

Cara Delevingne and Kate Moss attend the Burberry Prorsum show during London Fashion Week Spring Summer 2015 on September 15, 2014 in London, England. (Photo by Anthony Harvey/Getty Images)

An airplane passes the moon as it makes its approach to Philadelphia International Airport, Sunday, September 7, 2014, in Philadelphia. (Photo by Matt Rourke/AP Photo)

Young Christian Lebanese women, who are members of Kataeb Phalangist party, show their skill in handling arms while they train in a village between Christian-controlled eastern port of Jounieh and the Christian village of Zahle in the west Lebanon on September 9, 1976. The Lebanese civil war erupted in April 1975. (Photo by Erich Stering/AFP Photo)

A 13-month-old chimp named Fumo carries a “Christmas present” of food treats in wrapping paper under his arm during a Christmas-themed feeding time at Sydney's Taronga Park Zoo, December 9, 2014. Fumo, meaning “chief” or “spear” in Swahili, is one of the latest additions to the zoo's successful primate breeding program. (Photo by Jason Reed/Reuters)