Seasonal Diet of Khulan (Equidae) in Northern Xinjiang

Mongolian khulan, khulan or Mongolian wild ass, are the largest surviving subpopulation of the Asiatic wild ass (Equus hemionus Pallas, 1775). Due to the loss of habitat as a result of human settlement and developmental activities, poaching and competition with domestic livestock, the total population of khulan has declined significantly. Now the range of the khulan is located only in the Gobi region of southern Mongolia and northern China. The species is listed as rare in the China Red Data Book of Endangered Animals, and classified as a Category I protected species since 1989. E. hemionus is also included in Appendix I of CITES and listed as EN by IUCN.

An animal’s diet is a fundamental aspect of its ecological niche, and quantifying diets has long been and continues to be  the first step in studying a species’ basic ecology. To date, the feeding ecology of khulan has not been analyzed in detail, and early studies were mostly descriptive or restricted to autumn and the cold seasons.

In order to give preliminary results about quantitative botanical analysis of forage samples obtained from faeces, and compare their diet with that provided by their range over all seasons, the natural diet of khulan was observed over the period of a year in northern Xinjiang, China, using faecal analysis. Herdsmen with domestic animals stay in the nature reserve mostly during winter. Domestic sheep (Ovis aries) are the main livestock animals, which have a considerable impact on the khulan’s diet and feeding behaviour. So, the winter food habits of the khulan and domestic sheep were also compared.

The faecal analysis method demonstrated that khulan ate 46 species of plants during the year. Diets varied seasonally, with the widest food breadth in winter (0.43) and the least in summer (0.10). Chenopodiaceae and Poaceae were major foods of khulan, and during spring, forbs were quite important as well. In contrast, Stipa glareosa was preferred during spring and summer, but consumed less during autumn and winter. Shrubs dominated the khulan’s natural diet during autumn and winter. The dietary overlap between khulan and domestic sheep was 48.3% during winter. As a grazer living in arid environments, khulan ate more shrubs than other equids living in grassland, and their winter diet was an adaptation to avoid competition from domestic sheep. The number of sheep in the reserve should be reduced to lessen the pressure of competition.

The result has been published on Italian Journal of Zoology, 2012, 79(1): 92–99. The paper is also archived at http://www.tandfonline.com/doi/abs/10.1080/11250003.2011.620635.