About Treron formosae Swinhoe, 1863
Treron formosae, commonly known as the Taiwan green pigeon, is visually similar to the Wedge-tailed green pigeon, but typically has darker plumage. Females have various shades of green across their entire bodies, while males have a distinctive purple-grey patch on their wings. eBird describes this species as a variable green pigeon that lives in subtropical and tropical lowland broadleaf evergreen forests. The subspecies native to the Ryukyu Islands is comfortable around people and sometimes occurs in parks and gardens, while the Taiwan subspecies is more timid. The Ryukyu and Taiwan subspecies are sometimes classified as separate species, because Taiwan individuals are much smaller and have a rufous cap. This pigeon is similar to the White-bellied Green-Pigeon, but the feathers around its legs are never white, its face is less yellowish, and the white edges of its undertail coverts are narrower. Its song is a low, whistling poo-aa-poooo that rises and trills at the end, reminiscent of a bamboo flute. This species inhabits subtropical broadleaved evergreen forest and cultivated fields with nearby trees. On small islands, it mainly lives in lowlands and hills, but it is primarily a montane species on Taiwan, where it can be found up to 2,000 metres (6,600 ft). The IUCN has assessed this bird as near threatened, and its main threats are habitat loss and hunting.
