Vietnam Primate Conservation Status Review 2002 - Hoang Lien ...

Vietnam Primate Conservation Status Review Part 2: LEAF MONKEYS
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During a FFI survey in January 2002 a population of Tonkin snub-nosed monkeys was discovered in
the nature reserve. Locals reported about two groups of Tonkin snub-nosed monkeys with 20 to 30
individuals each.
On 16 January 2002 two local hunters from Khuon Lang village, Tung Ba commune killed one male
weighing 16 kg. On three occasions Tonkin snub-nosed monkeys were observed: on 20 January 8
adult animals were seen; the group was probably a male group and estimated to comprise 15 to 20
individuals; on 21 January 13 animals were seen (7 adults, 3 sub-adults, 3 babies); the group was
estimated to comprise 25 to 30 individuals; on 22 January probably the same group was seen and 9
adults and 5 babies observed. A local guide counted 27 individuals and the group was estimated to
comprise more than 30 individuals.
The whole population is estimated to comprise 50 individuals. This is currently the northernmost
population of the species and most probably a relic population which had in the past a larger
distribution including Phong Quang and Tay Con Linh Nature Reserves.
Cham Chu Nature Reserve (TUYEN QUANG)
Special use forest: Nature reserve
Tonkin snub-nosed monkey status: Occurrence confirmed, last evidence in 2001 (sighting) (Long &
Le Khac Quyet, 2001)
Cham Chu is a mountain range stretching from southeast to northwest and forms the boundary
between Chiem Hoa and Ham Yen Districts (Tuyen Quang Province). It is covered mainly with secondary
forest, which can be found only above 800m a.s.l. (Dang Ngoc Can & Nguyen Truong Son, 1999).
Several snub-nosed monkey specimens have been collected in Chiem Hoa District. One male skin
(IEBR 1437) was collected in the district (date and collector unknown). One adult male (ZMVNU 139)
and two adult male skulls (ZMVNU 146 and 544) were collected in November 1962 (unknown collector).
In December 1962, an adult female (ZMVNU 140) was collected in Phuc Thinh locality, about 10 km
east of Cham Chu (collector unknown) (Fooden, 1996).
In March 1992, Ratajszczak et al. (1992) reported the occurrence of R. avunculus on Cham Chu
mountain on the basis of interviews. Local hunters reported 20 to 40 individuals. Furthermore, two
skulls, a dried hand and a foetus were seen in a H’mong house on the slope of the mountain. These
specimens were the remains of two animals shot from a group of 15 animals two weeks previously.
One of the skulls is now kept in the Forestry College of Xuan May (FCXM 010).
In November 1999, FFI conducted a survey in the district with a special emphasis on the Tonkin
snub-nosed monkey (Dang Ngoc Can & Nguyen Truong Son, 1999). The survey was primarily
concentrated on the northeastern part of Cham Chu mountain, included in Trung Ha and Ha Lang
Commune territories.
Interviews conducted in Trung Ha Commune report that snub-nosed monkeys still occur on the mountain
range. A group of 22 to 25 animals were reported by 10 interviews on Khau Vuong and Khau Cang
mountains (22 O 14’N/105 O 04’E). In this area, a Tay hunter met a group of 30 animals in 1990 and killed
an adult female, while 4 other individuals may have been killed in 1994. In 1998, a Tay hunter from
Khuon Pong village shot 3 animals. To confirm his claim, he showed to the team the three skeletons
and the three tail tips. Bones were kept for making monkey balm. The last animals collected by a local
hunter in this area, a female and its offspring, were reported to have been shot in September 1999.
Three other informants claimed that a group with 8 to 10 members still lives on Khuon Nhoa mountain
(22 O 15’30”N / 105 O 02’15”E). The last sighting was in 1998.