Persian onagers, a type of wild ass, are native to Iran and are extremely endangered. There are only about 500 to 600 onagers left in their native habitat. The World Conservation Union (IUCN) lists the onager as endangered. Poaching, competition with livestock and habitat loss continue to threaten them.
In 2008, the National Zoo’s Conservation and Research Center acquired five Persian onagers. They arrived at our facility in February 2008. The older female was approximately seven months pregnant and we estimated that the younger female, believed to be her daughter, was less than two years old. We think the ages of the males are 15 years old, five and one year old.
Typically, Persian onager males are solitary and territorial, so at CRC they live in individual pastures connected to an enclosed barn. The two females live together. They have a strong bond and tend to stay close to each other. In the wild, onagers live in groups that include multiple females, their offspring, and usually only one male.In May 2008, scientists incorporated the two females into ongoing research focused on understanding onagers’ fundamental reproductive biology. Specifically, we began taking daily urine and fecal samples from each female for hormone analysis. The females are now accustomed to this routine, and they receive a treat for providing us the sample. Early in the study, the females had sometimes taken up to two hours to provide samples, however, the collection time gradually decreased as the onagers learned that they will receive a treat as their reward. The entire process of sample collection now takes about 30 minutes every day. On June 29, 2008, the pregnant female gave birth to a healthy colt.