Bird Diversity, Biogeographic Patterns, and Endemism of the Eastern Himalayas And Southeastern Sub-Himalayan Mountains

Species distribution and species diversity pattern have vexed ornithologists in Southeast Asia and the Himalayas. The species diversity debate continues, because the baseline data for such analysis are still very incomplete, especially in some parts of Asia. We conclude, from currently available data sets such as museum specimens, that the ornithological affinities of northern Kachin State are rather with the eastern sub-Himalayas and western Yunnan, and we cannot (yet) confirm a spatially narrow turnover zone between South and Southeast Asia. Nevertheless, the local endemism of bird species (i.e., sub-Himalayan slopes of northern Kachin State) is high and there is a strongly marked elevational turnover from south to north. Recent surveys in Assam, Arunachal Pradesh (northeast India), Yunnan (southwest China), and Kachin State (northern Myanmar) have revealed taxa not previously known, including three from Arunachal Pradesh and Kachin State since 1997. The descriptions are based on museum work in combination with genetic analysis and extensive field studies (e.g.,Jabouilleia naungmungensisandTesia olivea chiangmaiensis). Additionally, several taxa have been revised on the basis of new insights from surveys of the region (e.g.,Cyornis banyumas–C. magnirostris) or phylogenetic analysis (e.g.,Phylloscopus). We present data on these new species and discuss distributional areas in the context of species richness gradients.