Presbytis sabana (Thomas, 1893)
|
publication ID |
https://doi.org/ 10.5281/zenodo.6867065 |
|
DOI |
https://doi.org/10.5281/zenodo.6863390 |
|
persistent identifier |
https://treatment.plazi.org/id/CE199B17-FF98-FF9E-FA03-6F44FB54F7A6 |
|
treatment provided by |
Jonas |
|
scientific name |
Presbytis sabana |
| status |
|
111. View Plate 47: Cercopithecidae
Sabah Grizzled Langur
French: Langur de Sabah / German: Sabah-Langur / Spanish: Langur de Sabah
Other common names: Crested Grizzled Langur
Taxonomy. Semnopithecus sabanus Thomas, 1893 ,
Malaysia, Sabah, Paitan.
Until recently, P. sabana was classified as a subspecies of P. hoser, but it is morphologically distinct. Monotypic.
Distribution. N Borneo in most of Sabah State, as far SW as Kalabakan (4° 26’ N 117° 29’ E); its occurrence in N Kalimantan is not confirmed. View Figure
Descriptive notes. Head-body 48-56 cm, tail 65-84 cm; weight 6-7 kg (males) and 5. 5-6 kg (females). The Sabah Grizzled Languris gray above and below, except white belly and inner surfaces of limbs, contrasting with black on hands and feet. Crown is gray, with a tall black crest on back of head and two frontal whorls. Facial skin is reddish, with bluish lips and a pair of distinct black spots on each side of the face, between eyes and mouth—a pattern sometimes seen in more contrastingly colored individuals of Hose’s Langur ( Presbytis hoset).
Habitat. Evergreen, lowland, riparian, and montane rainforest. Sabah Grizzled Langurs will also enter tree plantations.
Food and Feeding. Sabah Grizzled Langurs eat mainly young leaves, unripe fruits, seeds, and flowers. Diets vary with the extent of habitat degradation (logging), in different forests, and at different times of the year. On average, young leaves comprise 42-45% ofthe diet,fruits 3-25%, seeds 17-21%, mature leaves only 1-5%, and flowers 3% or less. They also eat buds, bark, insects, and bird eggs, and nestlings. More leaves, especially those oflianas (mostly Fabaceae ), are eaten in unlogged forest (78% of the diet vs. 60% in logged forest), and more fruits and seeds are eaten in logged forest (19% fruits and 21% seeds vs. 3% fruits and 17% seeds in unlogged forest).
Breeding. Infants are weaned at ¢.300 days; they are consideredjuvenile at c.11 months of age and subadult at 21-36 months. Infants are white, with a black cruciform pattern across their backs and shoulders. Females first give birth at ¢.3 years old and usually in July-October.
Activity patterns. The Sabah Grizzled Langur is diurnal and arboreal. As for other species of Presbytis , resting dominates the activity budget, necessary to ferment and digest their leafy diet. Groups feed and forage for c.14-17% of the day,rest for 45-49%, travel for 30-32%, and indulge in social activities for 4-7-6%. They travel and forage mostly in the middle and upper forest canopy at heights of 10-30 m. They sleep high in the middle and upper canopies of emergent trees. Their locomotion involves quadrupedal walking (¢.47%), climbing (c.22%), running (c.12%), occasional leaping (c.10%), vertical clinging and leaping (c.7%), and rarely suspensory swinging (c.1%) and hopping (c.1%).
Movements, Home range and Social organization. The Sabah Grizzled Langur is territorial and lives in one-male groups of up to 14 individuals, with 2-6 females and their young. Home ranges vary from ¢.35 ha to 125 ha, and daily travel distances are ¢.700-800 m. Males produce loud calls that are spacing vocalizations and carry some distance. They are simpler in structure than is typical of Presbytis and are similar to those of Hose’s Langur, differing only in a few details. Long calls or “spacing calls,” as they are called, are described as “gargling growls.” When groups meet, males become agitated; they run and leap, uttering series of these gargling growls. Their alarm calls for predators are staccato grunts. Females disperse from their natal groups. Densities are estimated at 2-1 groups/km?, or ¢.16 ind/km?®. They occasionally form mixed species groups with Maroon Langurs ( P. rubicunda ), although where one is present, the other tends to be scarce or absent.
Status and Conservation. CITES Appendix II. Classified as Endangered on The IUCN Red List (as P. hosei sabana ). The Sabah Grizzled Languris protected by Indonesian law under the name P. aygula . Hunting for food and bezoars, believed to have medicinal properties, is its major threat, and believed to be the principal cause for its decline. The Sabah Grizzled Langur seems to survive selective, light logging quite well, but logging that destroys the forest canopy (and eliminates their sleeping trees) and clearcutting are major threats. It occurs in Danum Valley Conservation Area, Tabin Reserve, Sepilok Orang Utan Sanctuary, and Lower Kinabatangan and Maliau Basin conservation areas in Sabah. It may also occur in Crocker Range Park. There are no reports of the Sabah Grizzled Langur in captivity.
Bibliography. Bennett & Davies (1994), Brandon-Jones (1996), Brandon-Jones et al. (2004), Groves (2001), Mitchell, A.H. (1994, 2011), Nijman, Meijaard & Hon (2008), Payne et al. (1985), Rodman (1978).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
