China Subregional Avian Endemism and Biodiversity Conservation

Abstract

Richness of endemic species is considered important for biodiversity conservation and avifaunal regionalization, but no detailed studies concerning the subregional endemism have yet been done in China. Here we investigate the assemblage of China avian endemics of each avifaunal subregion, and analyze the faunal subregional species diversity, subspecific differentiation, and their relationships. The endemic species richness is found to be the highest in the Southwest Mountainous subregion where 60 species account for 57.1% of China’s 105 endemics. Seventy seven species accounting for 73.3% are monotypic. Twenty eight species (26.7%) occurred in only one subregion; the mean was 3.14±1.929 subregions, while 3 species were found widespread over 8 subregions. The number of species distributed only at one specific subregion (EOSR) is the highest in Taiwan subregion. The Southwest Mountainous subregion has the second highest EOSR and the highest richness of monotypic species, but the ratio of numbers of monotypic species or EOSR to the numbers of its subregional overall endemic species is not high in this subregion (68.3%; 10.0%). On the contrary, Taiwan subregion does not have higher richness of overall endemic species and monotypic species, but the EOSR is the highest, while the ratio of numbers of monotypic species or EOSR to the numbers of its subregional overall endemic species is also the highest among all subregions (76.2%; 71.4%). From the evidence of comparing subregional distribution of overall endemic species, EOSR, monotypic species and subspecific diversification, we may conclude that geographical isolation might be the main effect factor contributing to both subspecific diversification and avian subregional endemism in China. The higher endemic and monotypic richness in the Southwest Mountainous subregion may also indicate that the subregion’s avifaunal evolutionary and ecological isolation results from the highly diversified habitats and geographical environments as well as the historical effects from the primitive avifauna.