>Ixos virescens (Sunda Bulbul)

Sunda Bulbul

Sunda Bulbul
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Pycnonotidae
Genus:	Ixos (but see text)
Species:	I. virescens
Binomial name
Ixos virescens Temminck, 1825
Synonyms
Hypsipetes virescens (Temminck, 1825) (but see text)

The Sunda Bulbul or Green-winged Bulbul (Ixos virescens) is a songbird species in the bulbul family (Pycnonotidae). It is the type species of the genus Ixos.

Its genus is sometimes merged into Hypsipetes, presumably based on an error in the Sibley taxonomy which keeps them separate but includes I. virescens in Hypsipetes. But actually,Hypsipetes would to be sumsumed within Ixos of anything, as the latter name was established earlier. Either way, the specific epithet virescens, given to the present species by Coenraad Jacob Temminck in 1825, pre-dates the same name as given to the Nicobar Bulbul by Edward Blyth in 1845, and thus the latter species is sometimes referred to as H. nicobarensis (though correctly it would be Ixos nicobariensis). In even more extreme treatments, Iole is also wrongly subsumed within Hypsipetes, and even if the correct merger of Iole into Ixos is performed the Olive Bulbul (Iole virescens) also requires a new species name, as its was established by Blyth in 1845.

It is endemic to Indonesia where it occurs on Sumatra and Java, where its natural habitat is subtropical or tropical moist montane forests. It is not considered a threatened species by the IUCN.

>Ixos mcclellandii (Mountain Bulbul)

Mountain Bulbul

Mountain Bulbul
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Pycnonotidae
Genus:	Ixos
Species:	I. mcclellandii
Binomial name
Ixos mcclellandii Horsfield, 1840
Synonyms
Hypsipetes mcclellandii (Horsfield, 1840)

On Fraser Hill (Malaysia)

The Mountain Bulbul(Ixos mcclellandii) is a songbird species in the bulbulfamily(Pycnonotidae).
It is often placed in Hypsipetes, but seems to be closer to the type species of the genus Ixos, the Sunda Bulbul or Green-winged Bulbul (I. virescens).It is not considered a threatened species by the IUCN.

Taxonomy

The species was originally described by Thomas Horsfield in 1840.Subspecies include:

• I. m. mcclellandii
• I. m. ventralis
• I. m. tickelli
• I. m. similis
• I. m. holtii
• I. m. loquax
• I. m. griseiventer
• I. m. canescens
• I. m. peracensis

Distribution and habitat

It is found in Bangladesh, Bhutan, Cambodia, China, Hong Kong, India, Laos, Malaysia, Burma,Nepal, Thailand, and Vietnam. Its natural habitat is broadleaved evergreen forest forests, 800-2590m.

>Ixos siquijorensis (Streak-breasted Bulbul)

Streak-breasted Bulbul

Streak-breasted Bulbul
Conservation status
Endangered (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Pycnonotidae
Genus:	Ixos (but see text)
Species:	I. siquijorensis
Binomial name
Ixos siquijorensis (Steere, 1890)
Synonyms
Hypsipetes siquijorensis (Steere, 1890) (but see text)

The Streak-breasted Bulbul or Mottle-breasted Bulbul (Ixos siquijorensis) is a songbird species in the bulbul family (Pycnonotidae).

It is one of the species of Ixos that might warrant inclusion in the genus Hypsipetes – as long as this is kept separate from Ixos – as it may be a close relative of the Philippine Bulbul (H. philippinensis), which in turn is closely related to the type species of Hypsipetes, the Black Bulbul (H. leucocephalus).

It is endemic to the Philippines, where its natural habitat is subtropical or tropical moist lowland forests and subtropical or tropical moist shrubland. It is threatened by habitat loss.

>Ixos rufigularis (Zamboanga Bulbul)

Zamboanga Bulbul

Zamboanga Bulbul
Illustration by Keulemans, 1881
Conservation status
Near Threatened (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Pycnonotidae
Genus:	Ixos (but see text)
Species:	I. rufigularis
Binomial name
Ixos rufigularis (Sharpe, 1877)
Synonyms
Iole rufigularis

The Zamboanga Bulbul (Ixos rufigularis) is a songbird species in the bulbul family(Pycnonotidae).

It is one of the species of Ixos that might warrant inclusion in the genus Hypsipetes – as long as this is kept separate from Ixos – as it may be a close relative of the Philippine Bulbul(H. philippinensis), which in turn is closely related to the type species of Hypsipetes, the Black Bulbul (H. leucocephalus).

It is endemic to the Philippines, where its natural habitat is subtropical or tropical moist lowland forests. It is becoming rare due to habitat loss.

>Ixos malaccensis (Streaked Bulbul)

Streaked Bulbul

Streaked Bulbul
Conservation status
Near Threatened (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Pycnonotidae
Genus:	Ixos (but see text)
Species:	I. malaccensis
Binomial name
Ixos malaccensis (Blyth, 1845)

The Streaked Bulbul (Ixos malaccensis) is a songbird species in the bulbul family(Pycnonotidae). Depending on whether it is or isn't a particularly close relative of the type species of the genus Ixos, the Sunda Bulbul or Green-winged Bulbul (Ixos virescens), it might belong in a new genus.

What is presently known is that some Ixos species are close to Hypsipetes (which might warrant merging into Ixos), while others – including the Streaked Bulbul – are closer to Hemixos. But the affiliations of I. virescens remain to be restudied, and it is not clear to which group it belongs.

It is found in Brunei, Indonesia, Malaysia, Burma, Singapore, and Thailand. Its natural habitat is subtropical or tropical moist lowland forests. It is becoming rare due to habitat loss.

>Ixos everetti (Yellowish Bulbul)

Yellowish Bulbul

 

Yellowish Bulbul
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Pycnonotidae
Genus:	Ixos
Species:	I. everetti
Binomial name
Ixos everetti (Tweeddale, 1877)
Synonyms
Criniger Everetti Tweeddale, 1877 Hypsipetes everetti (Tweeddale, 1877)

The Yellowish Bulbul (Ixos everetti) is a species of songbird in the Pycnonotidae family. The scientific name commemorates British colonial administrator and zoological collector Alfred Hart Everett.

Distribution and habitat

It is endemic to the Philippines. Its natural habitat is subtropical or tropical moist lowland forests.

>>Genus Ixos

Ixos

Ixos
The Mountain Bulbul (I. mcclellandii) is provisionally placed in Ixos, until its relationships are resolved.
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Pycnonotidae
Genus:	Ixos Temminck, 1825
Diversity
7 species, but see text

Ixos is a songbird genus in the bulbul family, Pycnonotidae. It provisionally contains the following species:

• Yellowish Bulbul, Ixos everetti
• Streaked Bulbul, Ixos malaccensis
• Zamboanga Bulbul, Ixos rufigularis
• Streak-breasted Bulbul or Mottle-breasted Bulbul, Ixos siquijorensis
• Mountain Bulbul, Ixos mcclellandii (provisionally placed here)
• Sunda Bulbul, Ixos virescens (type species)

Systematics and taxonomy

The genus as traditionally delimited is not monophyletic; the Brown-eared Bulbul is placed inIxos, but in fact it is better separated in the monotypic genus Microscelis. The Philippine Bulbul is sometimes placed in Ixos but otherwise (and probably more appropriately) in Hypsipetes, where the Sulphur-bellied, Zamboanga and Streak-breasted Bulbuls might also belong.

The Mountain Bulbul and Sunda Bulbul – formerly H. mcclellandii and H. virescens – are provisionally placed in Ixos until the genus limits in bulbuls are firmly established. They are often included in Hypsipetes but this is an old error that was promoted in modern times by the Sibley taxonomy. In fact, I. virescens is the type species of Ixos, and though some sources advocate a complete merger of the two genera – and even the entire "Hypsipetes group" of bulbuls, which also includes Hemixos, Iole, Microscelis and Tricholestes –, being the oldest genus name Ixos would apply to all of them, rather than Hypsipetes as is often believed.

The most drastic course hardly appropriate however, since Alophoixus and Setornis cannot be excluded from the "Hypsipetes group", and an all-out merge would turn the resultant "genus"Ixos into an ill-defined "wastebin taxon". The erroneous inclusion of I. virescens in Hypsipeteshas caused the Nicobar Bulbul to be listed under its invalid junior synonym H. nicobariensisrather than the valid names H. virescens or I. nicobariensis.

The Streaked Bulbul, meanwhile, seems to be closer to Hemixos and perhaps Iole and maybe the Hook-billed Bulbul (Setornis criniger) than to Hypsipetes. Thus, given the lack of study of the Sunda Bulbul's affiliations, Ixos might eventually be reduced to the core group around I. virescens and kept well distinct fromHypsipetes. Or it may be that some species (such as I. malaccensis) are be split off into a distinct genus (for which no scientific name exists yet), while Hypsipetes is merged into the core group of Ixos.