A Tibetan rider fires his weapon as he perfoms his riding skills at the Qinghai Yushu Horse Racing Festival on July 27, 2007 in Yushu County of Yushu Tibetan Autonomous Prefecture, Qinghai Province, northwest China. The Horse Racing Festival of Tibetan nomads in Yushu Prefecture falls in late July and early August on the Tibetan calendar. During the festival, various equestrian skills will be performed along with singing, dancing and costume shows. (Photo by China Photos/Getty Images)

Elephant fights off hyenas to save baby. “This is the incredible moment an elephant came to the rescue of one of its babies being attacked by a pack of hyenas. The elephant is seen charging at the hyenas to ward them off its offspring. The photos were captured by American photographer Jayesh Mehta, 47, in the Savuti region of the Chobe National Park in Botswana”. Photo: The elephant is seen charging at the hyenas to ward them off its offspring. (Photo by Jayesh Mehta/Caters News)

Claudia Gadelha (L) of Brazil fights with Jessica Aguilar of Mexico during their Ultimate Fighting Championship (UFC) match, a professional mixed martial arts (MMA) competition in Rio de Janeiro, Brazil August 1, 2015. (Photo by Ricardo Moraes/Reuters)

Members of the Bolivian combined forces of army and police rest at their headquarters at the end of their ceremony for the task of fighting against drugs and the eradication of coca leaves in Chimore, east of La Paz, December 10, 2014. The government of Bolivia's President Evo Morales eradicated some 11,000 hectares of illegal coca plants and confiscated nearly 192 tons of drugs in 2014, according to the local media. (Photo by David Mercado/Reuters)

Students from Langata primary school run past riot police as they protest against a perimeter wall illegally erected by a private developer around their school playground in Kenya's capital Nairobi January 19, 2015. Riot police used teargas to disperse students at a school in Nairobi as the children protested against the potential loss of their playground. The playground was fenced off in December, during the school holidays, by a prominent developer who also claims ownership of the land. The title to the contested site is said to be in the name of Airport View Housing Limited, according to local media, with plans to use the space to build a parking lot for a hotel. (Photo by Thomas Mukoya/Reuters)

Young people fight for fun with their pillows, during the International Pillow Fight Day at the Place des Grottes, in Geneva, Switzerland, Saturday, April 4, 2015. The annual International Pillow Fight Day takes place in hundreds of cities around the world. (Photo by Salvatore Di Nolfi/AP Photo/Keystone)