An abandoned tank left by Boko Haram, February 20, 2016, seen on the road to Michika, Nigeria – a town formerly occupied by the insurgents. On April 14, 2014, 300 schoolgirls in the Chibok village in Nigeria were kidnapped by the terrorist group, Boko Haram. Two years later, the majority of these girls are still missing. According to the Global Terrorism Index Report 2015, Boko Haram, which operates mainly in Nigeria, has become the most deadly terrorist group in the world. (Photo by Danielle Villasana)

Tibetan boys dressed in traditional attire take part during a function organised by the Tibetan Refugee Community in Nepal,commemorating the 25th Anniversary of the Nobel Peace Prize conferment to exiled Tibetan spiritual leader Dalai Lama and the 66th International Human Rights Day in Kathmandu December 10, 2014. Nepal ceased issuing refugee papers to Tibetans in 1989 and recognizes Tibet to be a part of China. (Photo by Navesh Chitrakar/Reuters)

A member of the Community Police of the FUSDEG (United Front for the Security and Development of the State of Guerrero) search for a man, who ran away upon seeing the Community Police approach as they patrolled a street, in the village of Petaquillas, on the outskirts of Chilpancingo, in the Mexican state of Guerrero, February 1, 2015. Approximately 500 members of the Community Police from the FUSDEG took control of the security of the village of Petaquillas on the night of January 30 at the request of the people tired of the actions of organized crime, local media reported. (Photo by Jorge Dan Lopez/Reuters)

A man jokingly poses with a new installation of British graffiti artist Banksy's art in New York, October 20, 2013. (Photo by Carlo Allegri/Reuters)

The Dora the Explorer balloon moves through Times Square during the Macy's Thanksgiving Day parade Thursday, November 23, 2006 in New York. (Photo by Frank Franklin II/AP Photo)

Police, bystanders and soldiers aid a fallen soldier at the War Memorial as police respond to an apparent terrorist attack on October 22, 2014 in Ottawa, Canada. A gunman is believed to have shot a soldier as he was standing guard at the National War Memorial in Ottawa. It is believed police then chased the man into the main parliament building at Parliament Hill, where more shots were fired. (Photo by Wayne Cuddington/Postmedia/Barcroft Media/ABACAPress)

“YagYang”. The Apatani are tribal people living in north east of India in the region of Arunachal Pradesh. Tattooing and stuffing of large nose plugs is the particularity of these women. YagYang 75 years old, her husband passed away few months ago and she feels very alone, during my visit I was very fond of this woman and I wanted to spend some more time with her, so I asked her which was her favorite dish. The next day i returned with the fresh fish, as she mentioned, and when she saw me she was very happy and welcomed me with a big smile. Photo location: India. (Photo and caption by Passarini Mattia/National Geographic Photo Contest)

“Double head vulture”. On the day of windy days during raptors migration some people in my country start to catch these tired raptors, so in this day we go to photograph some raptors and we saw these tow tired vultures, so we start to drag them away from the hunters until they reach a good hidden place, to make them safe until they start a new journey. Photo location: Kuwait. (Photo and caption by Mohd Khorshed/National Geographic Photo Contest)