The impact of settled grazing on the grassland bird community of the Nantun area, northern Inner Mongolia

Abstract

The impact of settled grazing on grassland bird communities was investigated at ten sites along a 25 km long transect between Holobo and Baintara villages in the Nantun area of Hulunber grassland, northern Inner Mongolia, during the period 6-11 June 1997. Sixteen species of birds were recorded. Both the number of species and the density of individuals were found to be lower at sites closer to villages, due to the retrogressive change in the vegetation in such areas. Furthermore, the structure of the bird communities also differed, although Alauda arvensis predominated at almost all of the sites. In meadows, where the grass stood more than 25 cm high and covered more than 40% of the area, Emberiza aureola was the second most dominant species, accompanied by E. pallasi and Coturnix coturnix. Degraded grasslands close to the villages were characterised by Passer montanus, Hirundo rustica and H. daurica, which probably began breeding during the 1960s when the villages were constructed. Heavily grazed grasslands, though still dominated by A. arvensis, were poor in overall bird-species diversity, although it seems that Upupa epops and Vanellus vanellus might have been particularly attracted to areas of short grassland, such as those degraded by heavy gazing. Significant differences were found in the number of bird species and individual bird densities between grazing areas and mowing areas (t-test, p<0.05). It appears that the grassland bird communities of northern Inner Mongolia have been deleteriously modified since the introduction of settled grazing in the 1960s. Prohibiting the grazing of livestock during the growing season, and protecting these meadows for later mowing has a positive effect on the recovery of native grassland bird communities.