Blue-wattled bulbul

Blue-wattled bulbul
Conservation status
Data Deficient  (IUCN 3.1) [1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Pycnonotidae
Genus:	Microtarsus
Species:	M. nieuwenhuisii
Binomial name
Microtarsus nieuwenhuisii (Finsch, 1901) [2]
Synonyms
Poliolophus Nieuwenhuisii (protonym) Pycnonotus nieuwenhuisii Euptilosus nieuwenhuisii Brachypodius nieuwenhuisii

The blue-wattled bulbul (Microtarsus nieuwenhuisii) is a species of songbird in the bulbul family of passerine birds. ^[3] The specific epithet commemorates Dutch explorer Anton Willem Nieuwenhuis. The bird is endemic to the islands of Borneo and Sumatra. Its natural habitat is subtropical or tropical moist lowland forests.

Taxonomy and systematics

The status of this rarely seen bird is not known, primarily because it is not clear whether it is in fact a distinct species, or a natural hybrid between the black-headed bulbul and the grey-bellied bulbul or other closely related bulbuls. Alternate names for the blue-wattled bulbul include the Malaysian wattled bulbul, Nieuwenhuis's bulbul and the wattled bulbul.

Subspecies

Two subspecies are recognized: ^[3]

• †M. n. inexspectatus - (Chasen, 1939): extinct; once found on Sumatra
• M. n. nieuwenhuisii - (Finsch, 1901): found on Borneo

Status

It may be threatened by habitat loss but is only known from two specimens collected in 1900 and 1937, and few observations. Five sightings of the blue-wattled bulbul were recorded in Batu Apoi Forest Reserve in 1992. ^[4]

References

1. BirdLife International (2017). "Pycnonotus nieuwenhuisii". IUCN Red List of Threatened Species . 2017 e.T22712705A110040705. doi: 10.2305/IUCN.UK.2017-1.RLTS.T22712705A110040705.en .
2. Finsch, 1901. Poliolophus Nieuwenhuisii (protonym). Ueber eine neue Art Haarvogel aus Central-Borneo. Notes from the Leyden Museum, 23, no. 2, p. 95. BHL
3. AviList Core Team (2025). "AviList: The Global Avian Checklist, v2025". doi: 10.2173/avilist.v2025 . Retrieved 17 November 2025.
4. Collar, N.J. (2014). "Blue-wattled Bulbul Pycnonotus nieuwenhuisii and Black-browed Babbler Malacocincla perspicillata: two Sundaic passerines in search of a life" (PDF). BirdingASIA. 21: 37–44.