| Bare-faced bulbul | |
|---|---|
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| Bare-faced bulbuls inNa Hin National Park, Laos | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Passeriformes |
| Family: | Pycnonotidae |
| Genus: | Nok Fuchset al., 2018 |
| Species: | N. hualon |
| Binomial name | |
| Nok hualon (Woxvold, Duckworth & Timmins, 2009) | |
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| Synonyms | |
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Thebare-faced bulbul (Nok hualon) is a member of thebulbul family ofpasserinebirds. It wasnewly described from central Laos in 2009. It is one of the very few Asiansongbirds with a bald (featherless) face and is the first new species of bulbul to be described from Asia in almost a century.[2]
The species epithethualon is from theLao word for "bald-headed". A 2018 molecular phylogenetic study of the bulbuls suggested that the species does not fit in the clade containing the corePycnonotus and stood apart suggesting its placement in a new genusNok from Lao language for "bird" asNok hualon.[3]
The mainly olive-green bare-faced bulbul is distinctive in having a bare pink face with blueish skin around the eyes. The two specimens so farcollected were around 20 cm in length and weighed 32-40 g. The breast and belly are fawn-grey, the uppersides olive and the throat is off-white.[4] According to researchers, its call is a "dry bubbly tweet".
The bare-faced bulbul is known only from the limestonekarst region nearPha Lom in centralLaos. The area is characterised by steep terrain with bare limestone and low (less than 4 m in height)deciduous trees and shrubs. It seems likely that the species is restricted entirely to this habitat, though it may occur at other sites in Laos with similar habitats. Observations of similar birds were made in 1995 at another site. Limestone karst is the habitat of several newly discoveredendemic species, including the unusualLaotian rock rat.[4]
The bare-faced bulbul is mainly arboreal but sometimes perches on rocks on the steep hillsides. It is a conspicuous species, foraging during the day in pairs or as singles. Single birds tend to call regularly, and will link up with another before flying to a new area to forage. They have not been observed to joinmixed-species feeding flocks. The breeding behaviour of this species has not yet been observed.[4]
The bare-faced bulbul was assessed for the first time in 2010 byBirdLife International as ofLeast Concern, on the basis that the species has a large range, and there is insufficient evidence on population trend and size.[5] In the paper describing the species it was suggested that it be listed asdata deficient until further surveys of likely habitat were undertaken.[4] The limestone karst in which it lives is threatened by quarrying andhabitat degradation caused byovergrazing.[4]
