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

Vietnam Primate Conservation Status Review Part 2: LEAF MONKEYS
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Only one group of 8 Red-shanked doucs, without young animals, was observed on the route from Eo Cap to
Vooc (17 O 32’N / 106 O 12’E) in July 1998 (Nguyen Xuan Dang et al., 1998). Other reports are based on
interviews with local hunters of Ban Ruc (Thuong Hoa Commune) and Tang Hoa (Hoa Son Commune).
According to Pham Nhat & Nguyen Xuan Dang (1999), it is likely that Phong Nha possesses one of the
largest populations of Red-shanked doucs in Vietnam. However, from three surveys in this area,
totalling 30 days in the field, Vu Ngoc Thanh (pers. comm., 2000) found no signs of this species. In
addition, only one sighting of a small group without juveniles was reported in over four months of
intensive field survey by FFI teams from July to October 1998 (Timmins et al., 1999). The apparent
frequency of sightings of the species by previous researchers suggests a major population decline in
the Phong Nha-Ke Bang area (Timmins et al., 1999).
Pham Nhat et al. (2000) observed two groups of Red-shanked douc langurs on 22 and 23 April, 2000
in the Khe Rong area; groups of Douc langurs on four separate occasions in the Hung Lau-Da Ban
area, although it is probable that these were not all separate groups; a group of 22 animals was
observed twice on 22 and 26 July, 2000 and a group of 7-8 individuals was observed on 22 July.
Furthermore, a group of more than 10 individuals was encountered on 12 December, 2000. During
another observation the number of individuals could not be identified due to heavy rain. Also one
group of 10-15 Red-shanked douc langurs was observed on 23 July, 2000 (Pham Nhat et al., 2000).
The reports concurs with Timmins et al. (1998) that the population appears to be in decline due to
human impacts on their habitat such as snare setting and tree-oil extraction.
Records cited in Le Xuan Canh et al. (1997b) are not considered as admissible here. From 38 days in the
field, the authors reports more sightings of primates than from any other survey in Phong Nha, and they
do not provide justifications for these findings, nor explain how species and numbers were established.
Quang Trach District (QUANG BINH)
Special use forest: None
Douc status: Unknown, last report in 1960 (museum specimen)
Species recorded: P. nemaeus (specimen)
One juvenile male Red-shanked douc langur (ZMVNU 101) was collected in April 1960 by Bach Thu
Chon in Deo Ngang mountains.
Vinh Linh District (QUANG TRI)
Special use forest: None
Douc status: Provisional occurrence, last report in 1997 (Nadler, 1997c)
Species recorded: P. nemaeus (living animal)
In May 1997, the EPRC received one adult male which had been hunted and confiscated in this area.
Dakrong Nature Reserve (QUANG TRI) and Phong Dien Nature Reserve (THUA THIEN-HUE)
Special use forest: Nature reserve
Douc status: Provisional occurrence, last report in 1998 (Le Trong Trai & Richardson, 1999a)
Species recorded: P. nemaeus (interview and specimen)
This area possesses the best extent of lowland forest in Central Vietnam. During the feasibility study to
establish two nature reserves there, carried out by BirdLife and FIPI in June and July 1998, Red-shanked
douc langurs were reported in interviews and one specimen identified (Le Trong Trai & Richardson, 1999a).