Breeds only on small islands, thus in the breeding season restricted to lowland (and often fairly degraded) forest. In the non-breeding season, moves to Taiwan's montane forests where it occurs up to 2,000 m (Gibbs et al. 2001, Lin et al. 2016). There are some records from Taiwan in all months, thus some/few (non-breeding) birds may remain on the island year-round.

T. formosae (as defined following the taxonomic change, and incorporating filipina) occurs on Lanyu Island and Chinese Taiwan, Batan, Calayan, Camiguin Norte and Sabtang (Philippines). It is rare on Taiwan, China and uncommon and local on the Batanes (BirdLife International 2001, Gibbs et al. 2001, Allen 2020).

Conservation Actions Underway
None are known, but the species occurs in numerous protected areas in Taiwan, China. 

Conservation Actions Proposed
Survey to assess population size. Regularly monitor at certain sites throughout its range to determine population trends. Investigate the extent of hunting by local residents. Where relevant, control hunting where possible, perhaps using awareness campaigns. Protect significant areas of suitable forest across its altitudinal range.