Abstract:

Objective: This study aimed to understand bird composition and quantity change trend in summer, and the effect of habitat changes on bird community composition in order to provide scientific basis for the protection and management of the Qagan Nur wetland of Inner Mongolia in China. Method: By using line- and point-sampling methods, bird surveys at the Qagan Nur wetland were conducted for six consecutive years in August of each year from 2009 to 2014. The dominance index, the diversity index and the evenness index of the bird communities were analysed with the collected data. The IBM SPSS Statistics, Excel software and R software were used to test the bird community differences for different years with the Chi-square test, and analyse the correlation between meteorological factors and bird composition in each year with the linear regression analysis. Result: A total of 171 species in 37 families within 18 orders were recorded. Among them, there were 99 species of summer birds, 53 species of migrants, 16 species of residents, 2 species of vagrants and 1 species of winter bird. According to the habitat chosen by these birds, there were 58 species of grallatores, 50 species of songbirds, 41 species of natatores, 13 species of raptors, 4 species of terrestores, and 5 species of scansores. According to their endangered status, there were 2 species ranked as key protected first class species in China, and 23 species ranked as key protected second class species in China. Baer's Pochard (Aythya baeri) and Siberian Crane (Grus leucogeranus) were listed as critically endangered; the Oriental White Stork (Ciconia boyciana), Saker Falcon (Falco cherrug) and Far Eastern Curlew (Numenius madagascariensis) were listed as endangered; There were 7 species listed as vulnerable and 10 species listed as near threatened by IUCN. There were 73, 44, 156, 126, and 92 species listed on the List of Bird Species in accordance with the migratory bird protection agreement between China and America, Australia, Russia, South Korea and Japan, respectively. In the six years, the similarity index for summer birds was relatively high, and the compositions of the dominant species, the typical species and the rare species changed in different years. The result of the Chi-square test showed that there were significant differences in the number of species, the number of birds and the diversity index across years. The number of orders and families increased significantly from year to year. The number of summer species, the percentage of resident species and the percentage of the relative number of resident birds also increased from year to year. The number of grallatores and natatores decreased, whereas the percentage of the relative number of songbirds increased significantly. The results of the correlation analysis between meteorological factors and bird composition revealed that bird families were significantly positively correlated with the min temperature. The diversity index and the evenness index were extremely significantly positively correlated with the min temperature. The dominance index was extremely significantly negatively correlated with the min temperature. The number of summer species was significantly negatively correlated with the max temperature and was extremely significantly positively correlated with the relative humidity. The percentage of the relative number of natatores was significantly positively correlated with the relative humidity. The number of natatores species was significantly negatively correlated with the average temperature. Conclusion: With the shrinking of the Qagan Nur wetland and lake, the increasing of saline alkali land, grassland and forest land, the species and quantity of grallatores and natatores have a downward trend, while the number of songbirds has increased. It is suggested that long-term avian surveillance systems should be established and that effective management methods should be taken to protect the bird communities and their habitats in the Qagan Nur wetland.

Key words: birds in summer, composition, trends, the Qagan Nur wetland