Images of a herd of Indian bisons were captured by a ranger with his smart phone in the Naban River nature reserve in south Yunnan on May 17. With an estimated total of 10, the gaur group was the largest photographed by smart phones in the reserve.

 Liu Xiaochang, the ranger, took the photos near the Da’an village of Mengsong Township in Menghai County, south Yunnan’s Xishuangbanna Dai Autonomous Prefecture.

Data collected in 2013 and 2014 shows that the number of Indian bisons in Xishuangbanna dropped to around 160 from around 605 in the 1980s. Since then, local protection efforts to the endangered species have increased.

The gaur, also called the Indian bison, is the largest extant bovine. The species is native to the Indian subcontinent, Southeast Asia and China’s Yunnan Province. It has been listed as vulnerable on the IUCN Red List since 1986.