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.

Females in most populations of chiru or Tibetan antelope Pantholops hodgsonii migrate each year up to 350 km to summer calving grounds, and these migrations characterize the Tibet/Qinghai Plateau. We studied the migratory chiru population at the Ullughusu calving grounds south-west of the Arjinshan Nature Reserve in Xinjiang, China. The 750–1,000 km2 of suitable habitat at Ullughusu is at 4,500–5,000 m with sparse vegetation. We used direct methods (block counts, vehicle and walking transects and radial point sampling) and an indirect method (pellet counts) during six summers to assess population density. We also witnessed and stopped two major poaching events, in 1998 and 1999 (103 and 909 carcasses, respectively). Surveys suggested a drop in population density from 1999 to 2000. Poaching was not seen during summer monitoring after 1999, and surveys in 2001 and 2006 suggest that the population density is stable or recovering. We compare the Ullughusu calving grounds with those in the western Kunlun and discuss possible routes for migrating females.