New species of bush-warbler (cf Dutch Birding 22: 249, 2000)

A species of bush-warbler Bradypterus has been known to occur in the mountains of Taiwan for a long time. After its discovery in 1917, it was considered to belong to several Asian bush-warbler species by various authors, but only recently it was realized that the Taiwan population represents a separate species. It has now been formally described as Taiwan Bush-Warbler B alishanensis (Rasmussen, P C, Round, P D, Dickinson, E C & Rozendaal, F G 2000. A new bush-warbler (Sylviidae, Bradypterus) from Taiwan. Auk 117: 279-289). A colour painting by Ian Lewington of the new species and some of its congeners features on the cover of this issue of The Auk.
The new species differs from other bush-warblers especially by its distinct song, both sounding clearly different and showing a different structure in sonagrams. Furthermore, there are slight but consistent differences in bill structure, plumage coloration and wing formula. The name alishanensis is derived from the A-li Shan, the mountain where the first specimens were collected in 1917. Taiwan Bush-Warbler appears to be a relatively common breeding bird between 1200 and 3000 m, occurring in various, also disturbed, habitat types in at least two major mountain areas. It is, therefore, not considered threatened. The number of endemic bird species on Taiwan now stands at 15.
André J van Loon