Taxonomy
There are several races which are now often split into a varying number of separate species. Z. d. aurea (White's Thrush), including the questionable subspecies Z. d. toratugumi, is the migratory Siberian and north-east Asian form. Z. d. dauma (Scaly Thrush) breeds in the Himalaya and migrates to the foothills in winter. Z. d. horsfieldi (Horsfield's Thrush) is resident in Indonesia on the islands of Sumatra, Java, Bali, Lombok and Sumbawa. Z. d. neilgherriensis (Nilgiri Thrush) is resident in the hills of southwest India. Z. d. imbricata (Sri Lanka Thrush) is endemic to the hills of Sri Lanka and is particularly distinctive, being smaller, long-billed and rufous below. Z. d. major (Amami Thrush) is restricted to the Amami Islands in Japan.
The taxonomy of this group is still in flux. Some of these subspecies are very similar and the identity of some populations, such as those on Taiwan, is uncertain.
The Fawn-breasted Thrush (Z. machiki) of Indonesia and the Bassian Thrush (Z. lunulata) and Russet-tailed Thrush (Z. heinei) of Australia were also included in Z. dauma in the past.
Read more about this topic: White's Thrush