Abstract: Historic overlap zones of wild equids were small in Africa but extensive for Przewalski`s horses and Asiatic wild asses in Asia. Currently the Great Gobi B Strictly Protected Area in SW Mongolia is the only place where sympatric, free-ranging populations of these equids occur. This provides an unique opportunity to examine the co-existence of these little studied species and test the hypothesis that Przewalski`s horses are primarily adapted to mesic steppe habitats, whereas Asiatic wild asses are adapted to arid desert steppes and semi-deserts.
We monitored 9 Przewalski`s horses and 7 wild asses with satellite telemetry and superimposed the data on a habitat map derived from remote sensing (LANDSAT TM & ETM+-data) and ground sample plots. We tested for habitat preferences comparing use and availability with a logistic regression mixed model approach. Individuals were treated as random factors. Factor variables were tested for significant differences in subsequent Tukey post-hoc tests. Przewalski`s horses had non-exclusive home ranges of 152-826 km² and heavily selected for the most productive riparian plant communities. Asiatic wild asses also had non-exclusive home ranges, but with 4,449-6,835 km² they were 10 times larger than those of Przewalski`s horses. Asiatic wild asses seem to use plant communities more or less relative to their availability. Our results provide evidence for two parallel resource selection strategies. Our findings indicate that the Gobi areas provide an edge, rather than an optimal habitat for Przewalski`s horses. This leaves only small and isolated pockets of suitable habitat for future re-introductions. Asiatic wild asses, on the other hand, need access to large tracts of land to cope with the unpredictable resource distribution of the Gobi. Thus, Asiatic wild ass conservation requires a large scale approach.

Abstract: The Przewalski`s horse (Equus f. przewalskii) was extinct in the wild by the mid-sixties of the past century. The species only survived due to captive breeding from 13 founder individuals. In 1992 a reintroduction program was initiated in the Great Gobi B Strictly Protected Area in southwestern Mongolia. During it“s initial years, the project concentrated exclusively on P-horses. In the past decade activities have expanded significantly. The ecological project start point can be summed up as follows: i) species is extinct in the wild, ii) severe bottleneck, iii) practically no ecological data prior to extinction, iv) released into an extremely harsh, highly variable and poorly understood environment. The ecological knowledge constraints were compounded by i) highly emotional species, ii) simultaneous and competitive projects, iii) logistic nightmare, iv) non-scientific basis in planning phase. By the late 1990s project leadership and management was overhauled with research and scientific data firmly integrated into the decision-making process. Early scientific input concentrated on determining causes of death and low reproductive rates. The elucidation of the effects of endemic piroplasmosis on the population and subsequent management changes lead to remediation this deadly problem. P-horses have been fitted with ARGOS and GPS-ARGOS collars in order to determine home range and habitat preferences. Simultaneously the Mongolian wild ass and the wolf have been studied with these methods in the shared habitat. Satellite-based technologies provide the backbone for all habitat related project issues. At the onset (digitized Russian maps) data collection was restricted to the Eastern part of the Gobi B. Subsequently the spatial scale encompasses the entire Gobi Region in Mongolia and Northern Xingjian in China (e.g. Landsat, MODIS, NOAA, SRTM). Research has also focused on the role, needs and possible impacts of local semi-nomadic herders that use the protected area. Capacity building and training workshops (e.g. construction of fuel efficient stoves, felting) have been initiated. In 2007 a trans-boundary project in collaboration with the Xingjian Institute of Ecology and Geography of the Chinese Academy of Sciences, was initiated. This project aims to support rural communities of nomadic pastoralists living in the trans-boundary area of the Dzungarian Gobi, in China and Mongolia. Today, this project and the one in Hustain Nuruu (Mongolia) are the only ones that have resulted in free-ranging non-supplemented populations. In the Gobi B area some 120 (status 05.2008) P-horses roam in the protected area. In 2003 the IUCN downlisted the Przewalski\'s horse from to . Further downlisting to is predicted to occur in 2011. There is no consensus on when a reintroduction program is deemed successful. Clearly viewing the self-sustainable re-establishment of a population as a successful end-point is at best a short-term approach, constrained by time (today and now). Comprehensive interdisciplinary monitoring and research was and is the foundation for management strategies and decisions in this project. However, a self-sustaining financial base in conjunction with dedicated training and empowerment of local scientists and residents constitute essential prerequisites for the project”s future. Defining success and thereby inferring an end-point can easily lead to complacency compromising species persistence. As others have stated the ultimate project objective must be a constantly re-evaluated state of population persistence without intervention.