The Bornean peacock-pheasant (''Polyplectron schleiermacheri'') is a medium-sized

pheasant Pheasants ( ) are birds of several genera within the family Phasianidae in the order Galliformes. Although they can be found all over the world in introduced (and captive) populations, the pheasant genera's native range is restricted to Eura ...

. It is probably the rarest and certainly the least known of all peacock-pheasants. This elusive bird is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

lowland Upland and lowland are conditional descriptions of a plain based on elevation above sea level. In studies of the ecology of freshwater rivers, habitats are classified as upland or lowland. Definitions Upland and lowland are portions of a ...

forests of

Borneo Borneo () is the List of islands by area, third-largest island in the world, with an area of , and population of 23,053,723 (2020 national censuses). Situated at the geographic centre of Maritime Southeast Asia, it is one of the Greater Sunda ...

Description

The pheasant is up to 50 cm long, rufous brown and black spotted, with an elongated crest and nape feathers, black below and bare red skin around bluish iris eye. The breast sides are metallic blue-green, bordering the white throat and central upper breast. Its twenty-two tail feathers are decorated with large blue-green

ocelli A simple eye or ocellus (sometimes called a pigment pit) is a form of eye or an optical arrangement which has a single lens without the sort of elaborate retina that occurs in most vertebrates. These eyes are called "simple" to distinguish the ...

, which may be spread fan-like in display. The female is smaller and duller brown than the male. It has a brown iris and no spurs on its feet.

Distribution

Endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

, where it has been observed throughout the country, although its exact distribution is unknown. Central

Kalimantan Kalimantan (; ) is the Indonesian portion of the island of Borneo. It constitutes 73% of the island's area, and consists of the provinces of Central Kalimantan, East Kalimantan, North Kalimantan, South Kalimantan, and West Kalimantan. The non-Ind ...

is home to a more fragmented population (O'Brien & Kinnaird 1997).

Habitat

It inhabits lowland forests along the upper reaches of rivers, especially between 100 and 500 m above sea level, and appears to be absent from humid and swampy forests (O'Brien & Kinnaird 1997).

Diet

Its diet consists of fruits, seeds, and invertebrates, and is thought to be the source of seasonal movements linked to food availability (O'Brien & Kinnaird 1997).

Behavior

Non-social behavior This is a very shy species, taking to the vegetation cover at the slightest warning, running rather than flying. Difficult to observe, it remains one of the least understood peacock-pheasant species. Its presence is particularly noticeable during the breeding season, due to the calls uttered by the males and the arenas they maintain, cleared of leaves, for courtship (Hennache & Ottaviani 2006). Social behavior It is currently unknown, but they are likely solitary birds. Observations made in captivity are contradictory. According to Seitre (2004), who visited the Rezit Sozer breeding farm in Java, it is extremely difficult to keep both members of a pair together outside the breeding season. On the other hand, Kuah (in litt.) breeds Bornean spur-tails in pairs, like other species, and even in trios, without encountering major problems, except for constant infertility when the partners do not get along. If they do not fight, they ignore each other perfectly! Courtship Display The only observation of courtship displays was made by Denton (1978) and reported by Johnsgard (1999). Although the description is incomplete, it does not appear to differ significantly from those of the Hardwicke's spur-winged bat.

Taxonomy

The first specimens of the Bornean peacock-pheasant were collected by G. Fischer in Muara Teweh (southeast Borneo), skinned and sent to the Darmstadt Museum in Germany. They were scientifically named "Polyplectron schleiermacheri" by Brüggeman in 1877 in honor of Schleiermacher, then director of the museum (Hennache & Ottaviani 2006). Together with the phenotypically similar Malayan peacock-pheasant and Palawan peacock-pheasant it represents a basal group in its

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

; their radiation probably took place during the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58molecular clock The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleot ...

calibration method used by Kimball ''et al.'' (2001) is now known to be inappropriate, yielding far too low estimates in galliform birds. Being very poorly known, the Bornean peacock-pheasant was long considered to be a

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of the Malayan peacock-pheasant, but the two species are well-isolated geographically. The highly specialised anterior breast and upper neck plumage of male Bornean peacock-pheasant males are quite distinctive. Females of the two species are more difficult to distinguish. The rectrices of the Bornean species are morphologically and patterned intermediate between Palawan and Malayan peacock-pheasants.

Status and conservation

Because of ongoing habitat loss, small population size, and limited range, the Bornean peacock-pheasant is evaluated as

Endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

of Threatened Species. It is listed on Appendix II of

CITES CITES (shorter acronym for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of inte ...

References

External links

BirdLife Species Factsheet

Red Data Book
* gbwf.org �

{{Taxonbar, from=Q835098 Polyplectron Endemic birds of Borneo Birds described in 1877