Wednesday, August 01, 2007

Miller’s Grizzled Surili

Miller’s Grizzled Surili

Presbytis hosei canicrus Miller, 1934

Indonesia (E. Central Kalimantan) (2004)

All four subspecies of the Asian colobine monkey Presbytis hosei are endemic to north Borneo.

The high forehead and crest linking it with the white-fronted surili (P. frontata) from the southern

part of the island, mark the crested grizzled surili, P. h. sabana (Thomas, 1893) from eastern

Sabah (East Malaysia) as the most divergent subspecies. Its western neighbor, Everett’s grizzled

surili, P. h. everetti (Thomas, 1893) is unique to the genus in being sexually dichromatic. The

bandanna-like white tract of hair across the forehead of juveniles and male adults is reduced to a

white spot in female adults. In the south-eastern subspecies, Miller’s grizzled surili (P. h.

canicrus), all adults and juveniles much resemble adult female P. h. everetti, but have no frontal

white spot. P. h. canicrus is known only from the north-east Indonesian part of Borneo as far

south as the Kutai National Park, the only protected part of its recorded range (Brandon-Jones,

1997). Only an estimated 5% of the forest in this National Park has escaped timber concessions,

illegal settling, industrial development and fire (Meijard and Nijman, 2000). This leaves P. h.

canicrus probably critically endangered or even extinct, although no surveys have been

undertaken. The western subspecies, Hose’s grizzled surili, P. h. hosei (Thomas, 1889), is even

more likely to be extinct as most of its distribution coincides with that of the oilfields which

straddle the frontier between Sarawak (East Malaysia) and Brunei. P. h. hosei resembles P. h.

everetti, but the female retains her juvenile color at maturity (Brandon-Jones, 1997). There is a

slim chance that P. h. hosei survives in the northern part of the Similajau National Park in central

coastal Sarawak (Duckworth, 1995, 1998). Populations may also exist in Brunei which have

been much less subject to hunting and deforestation, but they are likely to be intermediate with P.

h. everetti. The reputed medicinal value of the bezoar stones sometimes formed in the gut makes

this species a target even for hunters uninterested in its meat.

Douglas Brandon-Jones

Cited from: Primates in Peril, the World’s 25 Most Endangered Primates 2004–2006, (Mittermeier, et.al , 2005)

Ilustration:
1. Interactive CD “Primata Indonesia” published by CI Indonesia,2003

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