- Reintroductions may play an important role in re-establishing key ecosystem functions. We focused on the role of reintroduced ungulates as internal seeds dispersers (endozoochory). In a comparative study we investigated which plant species are dispersed by Arabian oryx (Oryx leucoryx) a medium sized (65-75 kg) bulk feeder ruminant, Asiatic wild ass (Equus hemionus) a large (160-260 kg) hindgut fermenter, and dorcas gazelle (Gazella dorcas) a small concentrate selector ruminant (15-20 kg), in the Negev desert, Israel. The oryx and wild ass were locally extirpated during the 19 th century and recently reintroduced, while the gazelles are the only wide-ranging ungulate that existed continuously in the region. We collected 1-3% of the volume of clearly delineated fresh dung piles in dry stream beds where all species co-occur, and germinated them in sterile soil.