Population Trends and Evaluation of Captive Breeding and Reintroduction Programs of Endangered Persian Wild Ass (Equus hemionus onager) in Iran

Persian Wild Ass, the only representative of the order Perissodactyla, is the largest wild herbivore in Iran and inhabits the plains and hills of desert and steppe habitats. Study the status, population growth, and evaluation of management measures taken for this species in nature, reproduction, and rewilding areas are the main purposes of this study. According to the census data in 2021, there were a total of 1315 individuals, including 1231 individuals in the nature of Iran in the two protected complexes of Bahram-e-Gur and Turan and 84 individuals in the rewilding centers. In 2021, the minimum population was 170 individuals and the average of the last 14 years (2021-2008) was 160 individuals in the Turan complex, which decreased sharply compared to the population of 471 individuals in 1997 and 800 individuals in 1976. Changes in the population of the wild Ass in Bahram-e-Gur complex indicate that the population increases from 93 individuals in 1997 to 1061 individuals in 2021. The most important factors of population decline have been habitat loss, hunting, and droughts, and the most important factors in increasing the population of this species have been the intensification of conservation, forage supply, and water resources. Captive breeding programs and reintroduction have been prioritized for nearly two decades and have been successful to a large extent. Although this species is still in the group of endangered species, one of the most successful conservation programs executed in Iran is its management due to the population growth positively and the improvement of the conservation status.