A giant river otter, the world's largest otter species, looks out of its enclosure at the newly completed River Safari in Singapore, on March 25, 2013. (Photo by Wong Maye-E/Associated Press)

“Are you here for the Winery Tour?” This is a Western Grey Kangaroo caught lounging in the wineries of the Adelaide Hills in South Australia. This past Autumn has been a spectacular time for wildlife viewing and I got lucky to spot this guy while mountain biking in the hills. Such a funny stance it just begs the question... Have you been drinking? ...and or... Are you here for the Winery Tour? Such a spontaneous moment I figured it would be perfect for an entry. I hope you like it! Cheers. Photo location: Adelaide Hills, South Australia, Australia. (Photo and caption by Greg Snell/National Geographic Photo Contest)

A stuntman performs in a car at the “Well of Death” at an exhibition in Srinagar, India, Friday, May 23, 2014. In the Well of Death, stunt drivers on motorbikes and cars drive in circles around the vertical walls of the well-shaped construction. (Photo by Dar Yasin/AP Photo)

Chinese artist Zhou Jie takes a nap on an unfinished iron wire bed, one of her sculpture works, after lunch as a friend of hers looks on at Beijing Now Art Gallery, in Beijing August 11, 2014. Zhou started her art project titled “36 Days” on August 9, in which she would live inside an exhibition hall with an unfinished iron wire bed, some iron wire sculptures in the shape of stuffed animal dolls, a certain amount of food and her mobile phone, for 36 days. The entire process is open to visitors and she may also interact with them, according to Zhou. (Photo by Jason Lee/Reuters)

Children react after what activists said was shelling by forces loyal to Syria's President Bashar al-Assad near the Syrian Arab Red Crescent center in the Douma neighborhood of Damascus May 6, 2015. (Photo by Bassam Khabieh/Reuters)

A person poses on the track during a fashion competition at the Durban July horse racing event in Durban, South Africa, July 2, 2016. (Photo by Rogan Ward/Reuters)

A Muslim woman wearing a Hijab kicks the water in the Mediterranean Sea as a woman wearing a bikini stands nearby at the beach in Tel Aviv, Israel August 30, 2016. (Photo by Baz Ratner/Reuters)

Female winner Ane Guro Moen at Hardangervidda Marathon on September 2, 2017 in Eidfjord, Norway. Hardangervidda Marathon goes through parts of the National Park of Hardangervidda, passing through glaciers and waterfalls. (Photo by Kai-Otto Melau/Getty Images)