Abstract: The status of the Gobi khulan Equus hemionus subsp. is recorded as ``insufficiently known'' in the Species Survival Commission's Equid Action Plan. Recent counts confirm that Mongolia holds the most important population of the whole species. Since 1953, the animals have benefited from a protected status, but this is now challenged. A 5-year study in the B part of the Gobi National Park on one subpopulation showed that it has remained stable over the past 15 years with an adequate mean reproductive rate of 15% and a 50% survival rate over the first year. Age/sex related mortality and prey analysis indicate that wolf predation probably has some impact on the population, in particular for 4-6-year-olds of both sexes at the start of reproduction. Desert and mountain steppes are the khulan's year-round preferred habitat, but `oases', play an important role at the beginning of lactation. Anthropogenic factors affect both home range and habitat use through direct intervention or permanent occupation of the scarce water sources. Khulans of this subpopulation, unlike other Asian and African wild asses, form year-round stable, non-territorial families. These families and all-male groups join together into ``bands'' in winter, and herds of several hundred animals, where reproductive rate is highest, form throughout the year. The existence of such herds may thus be critical for the breeding success of the population. Our study provides the first detailed quantitative data for this subspecies, which will help to monitor changes in the future. # 2001 Elsevier Science Ltd. All rights reserved.

Abstract: The Asiatic wild ass Equus hemionus, or khulan, once ranged across much of Central Asia, but is now globally threatened. The largest free-ranging populations are now restricted to a 250-km wide area (range 100ñ400 km) across the Gobi Desert region of southern Mongolia. Over the last 23 years the population has moved further north and east into its former range. Surveys conducted in the 1970s and 1980s estimated that the Mongolian population contained fewer than 15 000 animals and was declining as a result of human exploitation and livestock competition. Aerial surveys (one in autumn 1994, two in spring 1997) were flown as line transects over portions of the khulan's range in Mongolia and ground surveys (’ve in spring, summer, and autumn 1994ñ97) were conducted by vehicle and foot. Sample sizes and areas surveyed were larger than previous surveys, and our methods were often more systematic. Population size was estimated at 33 000ñ63 000 wild asses in Mongolia. Animal density ranged from 4.2 a 1.3 to 19.1a 3.2 per 100 km2. Mean group size ranged from four to 35 animals in the south-western Gobi, four to seven animals in the southern Gobi, and three to 18 in the south-eastern Gobi. Our data suggest that Mongolia is the most important stronghold for the conservation of E. hemionus. Conservation management continues to be challenging because intensive studies on khulan biology and ecology are just beginning. As a freemarket economy continues to emerge in Mongolia, pressure from resource extraction interests and nomadic livestock herders to remove the khulan's protected status, permit harvesting and halt population growth and expansion, also makes implementation of research and conservation management programs more imperative.