Migrating Mongolian Wild Ass (image) University of Veterinary Medicine -- Vienna Caption Mongolian wild ass are among the most mobile of terrestrial mammals, ranging over thousands of square kilometers each year. Credit Photo: Petra Kaczensky / Vetmeduni Vienna Usage Restrictions The photo may only be used in the context of this press release. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.