Mahouts return home with their elephants carrying grass to feed them on the eve of the rhino census in Kaziranga National Park in Assam state, India, 24 March 2015. Kaziranga will be closed to visitors for the next two days for a census of the rhinos commencing 25 March, in a previous census in 2013 in the park the population of the Indian rhinos was 2329. (Photo by EPA/Stringer)

Indian Muslim devotees travel in an auto rickshaw during the Urs festival in Ajmer, India, Thursday, April 23, 2015. Thousands of devotees from different parts of India travel to the shrine of Sufi saint Khwaja Moinuddin Chisht for the annual festival marking the saint's death anniversary. (Photo by Deepak Sharma/AP Photo)

A riot police blocks a street during a march near a meeting attended by the Secretary-General of Organization of American State Luis Almagro and leaders from various communities in Managua, Nicaragua, December 1, 2016. (Photo by Oswaldo Rivas/Reuters)

Cardboard cut outs of the faces of three candidates for the Republican nomination for the 2016 US Presidential election (L-R) Ted Cruz, Donald Trump and Marco Rubio, are seen set up on urinals in a pub in London on March 1, 2016 as part of an informal poll for customers to log which they dislike the most. Part of the satirical television show The Last Leg, customers at the pub are able to choose which urinal to use and then log their poll on a list on the wall afterwards. (Photo by Justin Tallis/AFP Photo)

A woman doing yoga at a fountain, in downtown Stuttgart, Germany, Thursday, June 22, 2017. Weather forecasts predict hot summer weather as well as thunderstorms for some parts of Germany. (Photo by Marijan Murat/DPA via AP Photo)

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)

During his time in Ethiopia, New York-based art director and photographer Diego Arroyo spent time with the Hamar, Mursi, Dassanech, and Arbore Tribes. They, along with several others tribes, make up the 200,000 people situated in Africa’s Great Rift Valley. The people of the Omo Valley are still primarily herders and farmers, living an isolated and simple life. While they have yet to be truly touched by globalization, they could soon disappear. Their way of life is being threatened by a massive hydroelectric dam. (Photo by Diego Arroyo)

Pfc. Sebastian Rodriguez, machine gunner, Weapons Platoon, Lima Company, 3rd Battalion, 3rd Marine Regiment, Marine Rotational Force – Darwin, fires an M240 machine gun during a night squad-attack exercise, here, May 22, 2013. (Photo by Sgt. Sarah Fiocco/U.S. Marines)