A prisoner from the Pedrinhas prison is carried to receive medical help after he was injured during a fight between rival gangs inside the jail, in Sao Luiz, capital of Maranhao state, January 8, 2014. The recent posting on a major Brazilian news website of a video filmed last December 17 by Pedrinhas prisoners of the decapitated and tortured bodies of rival inmates inside the jail has highlighted some of the problems present in the country's prison system which houses nearly twice as many prisoners as its capacity, according to official statistics. (Photo by Douglas Cunha/Reuters/O Estado do Maranhão)

Smoke rises from a house days after part of the ground it was resting on collapsed into Lake Whitney, Texas in this June 13, 2014 file photo. I was covering the controlled burn of a house slowly falling into Lake Whitney due to the decaying cliff underneath. Asked to take photos from an aerial perspective, an instructor and I took off from Grand Prairie Municipal Airport around 9am. The burn, scheduled to start an hour later, was delayed. I love flying, but patience proved challenging as circling for nearly three hours gets boring fast. Once the fire started we only had 15 minutes to take photos because the plane was booked at 1pm. The owners invested their retirement savings in the house and were even advised by geologists that the ground was stable. To watch your investment literally go up in flames must take its toll emotionally. The owners said they don't expect their insurance to cover the loss. (Photo and caption by Brandon Wade/Reuters)

In this photo posted on Twitter, Sunday, May 3, 2015, and provided by NASA, Italian astronaut Samantha Cristoforetti sips espresso from a cup designed for use in zero-gravity, on the International Space Station. Cristoforetti, the first Italian woman in space, fired up the first espresso machine in space, which uses small capsules, or pods, of espresso coffee. (Photo by AP Photo/NASA)

Galapagos – Rocking the Cradle: Four major ocean currents converge along the Galapagos archipelago, creating the conditions for an extraordinary diversity of animal life, April 25, 2016. The islands are home to at least 7,000 flora and fauna species, of which 97 percent of the reptiles, 80 percent of the land birds, 50 percent of the insects and 30 percent of the plants are endemic. (Photo by Thomas P. Peschak for National Geographic/World Press Photo)

An African immigrant tries to jump a fence into a ferry terminal in the western Greek town of Patras April 28, 2015. Afghan, Iranian and Sudanese immigrants, living precariously in abandoned factories in Patras, southwest Greece, try to stow away on nearby ferries to Italy as they seek a better life in Europe beyond crisis-hit Greece. (Photo by Yannis Behrakis/Reuters)

Girls suffering from dwarfism take part in the disability pride parade in New York, July 12, 2015. The parade grand marshal was former U.S. Sen. Tom Harkin, the Iowa Democrat who 25 years ago sponsored the Americans With Disabilities Act. (Photo by Eduardo Munoz/Reuters)

Young girls take ballet lessons at the New Dreams dance studio in the Luz neighborhood known to locals as Cracolandia (Crackland) in Sao Paulo, Brazil, August 14, 2015. For the young girls learning to jump and plie, the dance studio provides a way forward and out of the difficult environment they have grown up in. Brazil is one of the world's highest consuming countries of crack cocaine, and Cracolandia, or “Crack Land”, located in the outskirts of Sao Paulo, is one of the most intense and brutal hubs. (Photo by Nacho Doce/Reuters)

Highly commended birds : Crested guan by Tim Hunt (UK). ‘This photo shows a crested guan in the cloud forests of Costa Rica as it pauses while foraging on a lone branch. Due to the clouds that are so typical for this habitat, I could often only photograph the bird’s silhouette against a grey sky. But then, for a short moment only, the sun broke through the clouds, and I overexposed the image by over two stops in order to blow out the background and allow this beautifully marked bird to stand out’. (Photo by Tim Hunt/GDT European Wildlife Photographer of the Year 2015)