NT
Taiwan Green-pigeon Treron formosae



Justification

Justification of Red List Category
This species is classified as Near Threatened because it is thought to have a moderately small population which is declining throughout its range, mainly as a result of hunting and habitat degradation.

Population justification
The global population size has not been quantified, but the species is described as rare on Taiwan and uncommon on the Batanes islands (Gibbs et al. 2001). Brazil (2009) has estimated national population sizes at < c.10,000 breeding pairs in Taiwan.

Trend justification
The species is suspected to be declining at a slow to moderate rate, owing to hunting and habitat degradation.

Distribution and population

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

Ecology

It inhabits subtropical broadleaved evergreen forest, cultivated fields where there are trees nearby, mainly lowlands and hills on small islands but is mainly a montane species on Taiwan, where it occurs up to 2,000 m (Gibbs et al. 2001).

Threats

In the Philippines, threats presumably comprise deforestation and hunting while commercial development through tourism is an imminent threat to Mt Irada. Threats elsewhere are poorly known.

Conservation actions

Conservation Actions Underway
None is known.

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.

Identification

c. 33 cm. A stocky green pigeon with a short tail, lacking any bright yellow tones in the plumage. The species has a dull orange cap contrasting with green face and neck and bold reddish-purple carpal patch. Similar spp. T. permagnus lacks the orange on the head and has a much duller carpal patch, contrasting little with the rest of the upperparts; it also has a longer tail. White-bellied Green Pigeon, which also occurs on Taiwan has a white or pale yellow belly and bright yellow tones on the face. T. formosae also has a much plainer tail. Voice. A 'weird, prolonged cry remarkably like a child in pain' (Hachisuka 1935; in Gibbs et al. 2001).

Acknowledgements

Text account compilers
Benstead, P., Mahood, S., Taylor, J., Martin, R & Symes, A.


Recommended citation
BirdLife International (2021) Species factsheet: Treron formosae. Downloaded from http://www.birdlife.org on 20/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 20/10/2021.