Yak near Yamdrok lake, Tibet. It is a long-haired bovinae found throughout the Himalayan region of south Central Asia, the Tibetan Plateau and as far north as Mongolia and Russia. The Tibetan economy is dominated by subsistence agriculture. Due to limited arable land, the primary occupation of the Tibetan Plateau is raising livestock, such as sheep, cattle, goats, camels, yaks, dzo, and horses. The Tibetan yak is an integral part of Tibetan life. (Photo by Dennis Jarvis)

Migrants ride on top of a northern bound train toward the US-Mexico border in Juchitan, southern Mexico, Monday, April 29, 2013. Migrants crossing Mexico to get to the U.S. have increasingly become targets of criminal gangs who kidnap them to obtain ransom money. (Photo by Eduardo Verdugo/AP Photo)

In this handout image supplied by Qatar 2022 The Al-Rayyan stadium is pictured in this artists impression as Qatar 2022 World Cup bid unveils it's stadiums on September 16, 2010 in Doha, Qatar. It has been designed to include a “media facade” that includes a membrane that acts as a screen for projections; news, commercials, sports updates and current tournament information and matches. (Photo by Qatar 2022 via Getty Images)

A woman surveys the damage after the earthquake on March 17, 2011 in Kensennuma, Japan. (Photo by Chris McGrath/Getty Images)

A boy fires confetti poppers as he participates in a procession to mark Eid-e-Milad-ul-Nabi, the birthday celebration of Prophet Mohammad, in Mumbai January 4, 2015. (Photo by Danish Siddiqui/Reuters)

Devotees offer prayers before taking a holy bath during the Swasthani Bratakatha festival in the Triveni River in Panauti near Kathmandu January 24, 2015. During the month long festival, devotees recite one chapter of a Hindu tale daily from the 31-chapter sacred Swasthani Brata Katha book that is dedicated to the God Madhavnarayan and the Goddess Swasthani, alongside various other gods and goddess and the miraculous feats performed by them. The devotees also go on pilgrimages to various temples, perform religious rituals, take a holy bath in the rivers and fast for a month, especially among women who believe fasting helps in their family's well-being or in getting them a good husband. (Photo by Navesh Chitrakar/Reuters)

A Palestinian man reacts after his house was flooded by rain water in Khan Younis in the southern Gaza Strip, November 9, 2015. (Photo by Ibraheem Abu Mustafa/Reuters)

A photographer takes a snapshot of the reflection of balloons as they take off from Balloon fiesta park in Corrales, N.M., near a north diversion channel reservoir Wednesday, October 7, 2015. (Photo by Roberto E. Rosales/Albuquerque Journal via AP Photo)