Landscape level research on the Asiatic wild ass in Mongolia

Mongolia is an important stronghold of the Asiatic wild ass (Equus hemionus, khulan in Mongolian) and has a global responsibility to ensure their conservation. Presently, Mongolia is anticipating the development of a commercialized agricultural sector that could easily engender a far greater intrusion of human activities in the Gobi environment than current pastoral livestock production. Development of other sectors of the Mongolian economy, especially mining and road construction, could also impact environmental security in general and habitat needs of the khulan and associated wildlife in particular. At present, the status and trend of the khulan population in Mongolia is difficult to assess, as no standardized monitoring has been installed and very little is known about khulan ecology and movement patterns. We believe that without immediate conservation actions prospects for long-term survival of the khulan are poor and the species may potentially face extinction as did the other native equid species of Mongolia the Przewalski`s horse (Equus ferus przewalskii). We propose a three year research project to: (1) assess to what extent (if any) the wild ass is affected or competes with domestic livestock and other human intrusions, and to what degree, (2) develop a dynamic habitat model for khulan, (3) assess the spatial integrity of the khulan population in Mongolia, and (4) test ground survey methods to design future- and interpret past wildlife surveys. The spatial scale and the temporal resolution of the anticipated habitat model are unique and in combination with satellite telemetry, direct observations, genetic analysis we believe that the proposed project will break new grounds for the understanding and conservation of khulan and other wide-ranging desert and steppe species in Central Asia. Rigorous testing and spatial modeling of a large dataset from ground surveys of low density large ungulates in a desert-steppe ecosystem can be expected to have implications for future designs. Subsequently, we aim to integrate these results in the development of a long-term conservation and management plan that should become the basis for both khulan protection and rural livelihood development.

The Mongolian Gobi is the last stronghold of the Asiatic wild ass (Equus hemionus). Anecdotal evidence suggests that the species may have lost as much as 70% of its range since the 19th century due to direct persecution and competition with humans and their livestock over water and pasture use. Using telemetry, population genetics, and distribution range data, we assessed the connectivity of the wild ass population in the context of natural and anthropogenic landscape features and the existing network of protected areas. Telemetry data showed that wild asses do not venture into areas with a mean biomass production >250gC/m2 /year and that steep mountainous terrain and fences act as movement barriers. Population genetics results identified two subpopulations and delineated a genetic boundary between the Dzungarian- and Transaltai Gobi. Historic and recent wild ass distribution data suggested that mean biomass production is a good proxy for human land-use intensity and can be used to predict wild ass occurrence. We find that conserving long term continuity of the wild ass population will need a Gobi wide landscape level approach, also including multi-use landscapes outside of protected areas, particularly in the southeast Gobi. In the southwest Gobi, allowing for openings in the border fence to China and managing the border area as an ecological corridor would improve connectivity and give wild asses access to another 100,000 km 2 of suitable habitat in Xinjiang province in northern China. Assessment of the wild ass population trend is challenged by the huge expanse of the distribution range ( 250,000 km 2 ), large scale movements, long flight distances, an uneven distribution, and large variations in group sizes on the animal side and the unavailability of suitable fixed- winged aircrafts on the researcher side. We developed a simulation program reflecting the entire survey process based on actual landscape and biological features. The results can be directly fed into program DISTANCE to assess what factors have the highest influence on the population estimates by comparing model scenarios with real survey data from the last 6 years. Our analysis suggests that we may have underestimated the number of wild asses present in the Great Gobi B Strictly Protected Area in south-western Mongolia, but also that line transects are unsuitable to detect population trends because of the low population density, the high variability in group sizes and the often clumped distribution of wild asses. Transect counts should be coupled with additional methods, e.g. minimum counts, carcass counts or area of occupancy derived from herder surveys, in order detect changes in population size. However, for a monitoring program not to only be an academic exercise it needs to be linked to a clear conservation strategy. In a next step a conservation strategy followed by area specific action plans for wild ass conservation in central Asia should be developed.