An American bison (bison bison) licks her new-born calf in the grasslands of the Janos Biosphere Reserve in Janos, in Chihuahua state, May 16, 2014. The bison is one of 300 endangered species in Mexico and fundamental for the recovery of the Chihuahan Desert grasslands according to the director of the El Uno Ecological Reserve. Bison are an essential part of the ecosystem in supporting populations of other species in the reserve. Bison break the ground with their step and allow plants to grow, promote water filtration and keep the grass at a height perfect for other species like the prairie dog to thrive. As part of the five-year old Bison Reintroduction Project by The Nature Conservancy, NGOs, universities and government agencies, eight more adult bison, five females and three males, just arrived from New Mexico and were released in Janos, totalling now 61 bison in the reserve. Picture taken May 16, 2014. REUTERS/Jose Luis Gonzalez (MEXICO - Tags: ANIMALS ENVIRONMENT)