An Amur tiger walks across a passageway after a news conference at the Philadelphia Zoo, Wednesday, May 7, 2014, in Philadelphia. The see-through mesh pathway called Big Cat Crossing is part of a national trend called animal rotation that zoos use to enrich the experience of both creatures and guests. (Photo by Matt Slocum/AP Photo)

“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)

Undated David Yarrow handout photo of a gorilla as the self-taught wildlife photographer promotes his book, Encounter. (Photo by David Yarrow/Clearview/PA Wire)

A pair of young visitors rushes through a tunnel of colored lights at the annual Garden of Lights display at Brookside Gardens on December, 06, 2015 in Silver Spring, MD. (Photo by Bill O'Leary/The Washington Post)

NYC no pants subway ride. Thousands of straphangers took their pants off for the 15th annual "No Pants Subway Ride" hosted by Improv Everywhere. People gathered at seven meeting points throughout the five boroughs at 3PM. All participants met up at Union Square around 5PM to and had a pant-less celebration and the afterparty at Webster Hall. (Photo by Paul Martinka/The New York Post)

Anton Unitsyn, Russia. Shortlist, Professional , Daily Life. Parkour jumpers on their daily training. On the background – one of the main Solvychegodsk sights – Blagoveshchensky Cathedral. This church is among 3 churches, that survived soviet times. At the begining of 20th century there were 13 churches in Solvichegodsk. After breakdown of the communism, Solvichegodsk as many small towns in russia is stuck in it's past. Despite everything, people in Solvichegodsk still belive in their positive future, and wait for wind of change. (Photo by Anton Unitsyn/Sony World Photography Awards)

A man sits in the back of a taxi with a goat after purchasing it from a livestock market ahead of the Eid al-Adha festival in Kolkata, India, September 8, 2016. (Photo by Rupak De Chowdhuri/Reuters)

A competitor shouts as he takes part in the “Tough Guy” adventure race near Wolverhampton, central England, on January 29, 2017. The Tough Guy event, which is being held for the final time in its 30th year, challenges thousands of competitors to run a gruelling course whilst negotiating over 200 obstacles including: water, fire, and tunnels. (Photo by Oli Scarff/AFP Photo)