Gee's golden langur

Gee's golden langur[1]
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Cercopithecidae
Genus: Trachypithecus
Species: T. geei
Binomial name
Trachypithecus geei
(Khajuria, 1956)
Gee's golden langur geographic range

Gee's golden langur (Trachypithecus geei), or simply the golden langur, is an Old World monkey found in a small region of western Assam, India[3][4] and in the neighboring foothills of the Black Mountains of Bhutan.[5][6] It is one of the most endangered primate species of India.[6] Long considered sacred by many Himalayan people, the golden langur was first brought to the attention of the western world by the naturalist E. P. Gee in the 1950s.[7][8] In a part of Bhutan, it has hybridised with the capped langur T. pileatus.[9]

Discovery and etymology

The earliest record of the golden langur is in Pemberton's 1838 paper which states that "Griffith observed these monkeys near Tongso in Central Bhutan."[10][11] However, Pemberton's work was lost and not rediscovered until the 1970s, the scientific discovery of the golden langur unfolded differently. In 1907, E. O. Shebbeare—who was out with some hunters and forest rangers—reported seeing a "cream coloured langur" in the vicinity of the Jamduar.[8][nb 1] However, neither a photograph nor a live or dead specimen was presented at that time. The first reference to the golden langur in print, as an animal of unidentified taxonomic status, was in a 1919 publication that stated: "Pithecus sp? – A pale yellow coloured langur is common in the adjoining district of Goalpara (Assam). Jerdon reported one from Terai, the adjacent district on the (west) side, which Blanford suggested might be P. entellus."[12][13]

At around the time of India's independence in 1947 a number of other sightings were reported. In February 1947, in the Forest Rest House visitor's book in Raimona, a few miles south of Jamduar, C. G. Baron reported seeing some langurs whose "whole body and tail is one colour – a light silvery-gold, somewhat like the hair of a blonde." A year later, back in Jamduar, H. E. Tyndale, a tea planter, reported seeing "Sankosh cream langurs."[13] However, it wasn't until a few years later that a focused effort to identify the golden langur was mounted by E. P. Gee, who traveled to Jamduar in November 1953. His team were able to observe three groups of golden langurs, all on the east bank of the Sankosh river. The first group was observed on the Bhutan side of the border; the second group, a large one of 30 to 40 individuals, a mile north of Jamduar on the Indian side; and a third group four to five miles (6.44 km to 8.05 km) south near Raimona. Colour movies of the second group were made by Gee.[13]

Golden langur.

In August 1954, Gee reported his findings to an expert at the Zoological Society of London, who advised that the golden langur might be a new species. In January 1955, Gee also reported his results to the Zoological Survey of India (ZSI) and, after showing his movies of the golden langurs, suggested that Jamduar be included in the then-upcoming ZSI-survey of that region. The suggestion received the support of Dr. Sunder Lal Hora, then Director of ZSI, and later that year six specimens of the golden langur were collected by the survey party.[13] The following year, Dr. H. Khajuria, a taxonomist who studied the specimens, described the new species naming it Presbystis geei in honour of Gee.[14][nb 2]

Taxonomy

There are two subspecies of this species:[1]

Physical description

The coat of the adult golden langur ranges from cream to golden; on its flanks and chest the hairs are darker and often rust coloured; the coats of the juveniles and females are lighter, silvery white to light buff.[15] The golden langur has a black face and a very long tail measuring up to 50 cm (19.69 in) in length.

Distribution

Map showing the two disconnected regions of distribution (within red rectangles) of the Golden Langur in Assam-Bhutan and Tripura.

The regions of its distribution are very small; the main region is limited to an area approximately 60 miles square bounded on the south by the Brahmaputra River, on the east by the Manas River, on the west by the Sankosh River, all in Assam, India, and on the north by the Black Mountains of Bhutan,[16] and the secondary region, 200 miles to the south-southeast, is in a small portion of the northwestern part of Tripura state. These biogeographical barriers are believed to have led to the radiation of species from the closely related capped langur (Trachypithecus pileatus).[17] The best range maps so far are Choudhury (2002)[18] and Choudhury (2008)[9]

Behavior and ecology

For the most part, the langur is confined to high trees where its long tail serves as a balancer when it leaps across branches. During the rainy season it obtains water from dew and rain drenched leaves. Its diet is herbivorous, consisting of ripe and unripe fruits, mature and young leaves, seeds, buds and flowers.

It generally lives in troops of about 8 (but sometimes up to 50) with several females to each adult male. The smallest golden langur troop was composed of four individuals, while the largest had 22, giving an average value of 8.2 individuals per troop. The adult gender ratio was 2.3 females to every male, although the majority of groups had only one adult male.[19]

Conservation

In 1988, two captive groups of golden langurs were released into two protected areas of the western region of the state of Tripura, India. As of 2000, one of these groups, consisting of six (and possibly eight) individuals in the Sepahijala Wildlife Sanctuary, had survived.[20]

Gee's golden langur is currently endangered; a total Indian population in 2001 of 1,064 individuals, in 130 groups, was recorded. Of these, approximately 60% were adults indicating a relative lack of infants and juveniles.[6] The relative death of infants and juveniles indicate a declining population and with the habitat being degraded by human activity. A fragmented but protected population in a rubber plantation in Nayakgaon, Kokrajhar district of Assam increased in population from 38 individuals in 1997 to 52 in 2002. The population has also adapted to feeding on dry rubber seeds.[21]

Notes

  1. ↑ Jamduar was a village in the early 1900s, which is now a part of the town of Kokrajhar
  2. ↑ The new name, Presbystis geei, came to be inadvertently included in Gee's 1955 short note which was published two months before Khajuria's 1956 paper proposing the name.[8]

References

Literature cited

External links

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