Responses of Tibetan antelope population to environment changes during the Holocene

Tibetan antelope is the only genus of large mammal endemic to the Tibetan Plateau. In the past decades, the antelope population has been significantly affected by human activities, including massive illegal hunting, followed by strict protection policies and establishments of natural reserves. Various techniques and many efforts have been devoted to monitoring antelope population fluctuation and migration in past decades. However, it remains unclear how the antelope population changed in the past, and how it varied with climate and environment. Here, we presented sedimentary records at Lake Zonag, one of the major calving grounds for the Tibetan antelope, to study past changes in antelope population and its response to environment in past 9000 years. The sedimentary fecal sterols, produced by antelopes, captured the sudden decrease in antelope population due to illegal hunting in 1980s, as well as the recent recovery because of protection. The antelope population varied significantly during the past 9000 years, generally following environment changes revealed by geochemical elements in the same sediment core. Large antelope population likely lived in environment with relatively warm and humid condition, while small antelope population occurred in adverse environment with relatively cold and dry condition. Two periods with notably low antelope population were observed at 5.1–4.5 and 4.1–3.7 ka. The increase in antelope population in the past 400 years likely resulted from wildlife protection from early Tibetans. This study provides a promising method to reconstruct past changes in antelope population, to study its response to environment changes, and to provide historical comparison for wildlife protection.