Styan's Bulbul — agujaceratops · CC0_1_0 via GBIF

Styan's Bulbul

Pycnonotus taivanus

台湾鹎

IUCN: Vulnerable China: Level II Found in China

Introduction

Pycnonotus taivanus is a species of bulbul endemic to eastern and southern Taiwan. It inhabits forest edges, scrublands, and human-modified areas. The species is characterized by its distinct head patterning with a black crown and white eye feathers. It faces significant conservation challenges due to hybridisation with the closely related light-vented bulbul, whose range overlaps in several areas following releases for Buddhist ceremonies. The species has become extinct in Yilan County and is listed as vulnerable to extinction.

Description

This bulbul has predominantly brownish plumage overall with a distinctive head pattern. The crown is completely black, contrasting with white feathers surrounding the eye. A black moustachial stripe runs below the beak. The wings and tail are brown, while the underparts are lighter, buff-colored. The bill is dark, and the legs are pinkish-brown. The species closely resembles the light-vented bulbul in overall structure and coloration.

Identification

The most reliable distinguishing feature from the light-vented bulbul is the head pattern. Styan's bulbul shows a fully black crown with white feathering around the eye, but with a black moustachial stripe below the beak. Light-vented bulbuls have a more restricted white patch and different head markings. Hybrids between the two species show intermediate characteristics: they possess both the moustachial stripe and white eye feathers, but the white feathering extends behind the crown, creating a distinctive hybrid signature.

Distribution & Habitat

Endemic to eastern and southern Taiwan. The species' range has contracted significantly, with complete local extinction documented in Yilan County. The species historically occurred throughout eastern and southern portions of the island but has declined substantially in many areas due to competitive pressure and hybridisation with the expanding light-vented bulbul population.

Behavior & Ecology

Not described in available sources.

Conservation

Classified as vulnerable to extinction. The primary threats are habitat destruction and degradation throughout its limited range, combined with ongoing hybridisation with the light-vented bulbul. The release of light-vented bulbuls for Buddhist ceremonies has expanded the latter species' range into areas where it historically did not occur, facilitating contact and breeding between the two species. This genetic swamping poses a significant long-term threat to the species' integrity.