Population increase at a calving ground of the Endangered Tibetan antelope Pantholops hodgsonii in Xinjiang, China

Females in most populations of chiru or Tibetan antelope Pantholops hodgsonii migrate up to 350 km each year to summer calving grounds. These migrations characterize the Tibet-Qinghai Plateau. The Ullughusu calving grounds adjacent to the Arjinshan Nature Reserve in Xinjiang, China, are used by multiple chiru populations and this calving ground recovered from major poaching events in 1998 and 1999, with a population increase from 2001 to 2006. We used direct methods (vehicle/walking transects and radial point sampling) and an indirect method (faecal pellet counts) from 30 June to 4 July 2011 to assess the chiru population at this calving ground. We saw substantially more chiru with all methods in 2011 compared to 2006, demonstrating that the population has increased and suggesting that conservation efforts have been effective.