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Survey Locates Critically Endangered Tonkin Snub-nosed Monkey in Vietnam

    Tonkin Snub-Nosed Monkeys  
  Tonkin snub-nosed monkeys
(Rhinopithecus avunculus)

Adapted from the report of
Thach Mai Hoang,
HUS, Vietnam National University - Hanoi

Two years of intensive surveys have confirmed the continued existence of one of the world's rarest primates in the forests of the Na Hang Nature Reserve, Vietnam. Once thought extinct, the Tonkin snub-nosed monkey (Rhinopithecus avunculus Dollman, 1912) was rediscovered in the late 1980's in two adjacent forests about 250 kilometers north of Hanoi. But despite action by the Vietnamese government establishing these forests as nature reserves and conservation efforts by multiple NGOs including Primate Conservation, the construction of a hydroelectric dam in the midst of their range at the beginning of this century appeared to have sealed their fate. Surveys since construction had reported no snub-nosed for several years and many thought them to locally be extinct.

Outside Na Hang Nature Reserve the world population of the Tonkin snub-nosed monkey is thought to be much less and 100 individuals so the Na Hang Reserve is of the highest importance to its survival. Despite this, conservation efforts had faltered because of the lack of snub-nosed sitings. Our recent field surveys, training and conservation work is an attempt to re-energize efforts in the Reserve.

The project began in 2009 and focused mainly on field work to determine if the snub-nosed monkeys remained in the forests surrounding Na Hang. In the long first year no R. avunculus were seen. Work was redoubled in 2010. Most important, the active cooperation of the Peoples' Resource and Conservation Foundation (PRCF) and Tuyen Quang Forestry Protection Department’s (FPD) Conservation Division allowed us to stay longer in the field and attract more participation by forest rangers and community members.

   

  An adult Tonkin snub-nosed monkey leaping up
in the Ban Bung Sector 31st October, 2010.
It’s head is obscured by foliage.
(Photo by Thach Mai Hoang)
   

  An adult Tonkin snub-nosed monkey looking at observer
from about 200 – 250 meters on 1st November, 2010.
(Photo by Hoang Trung Thanh)
   
  Hunting rifle confiscated in Khau Tep Area, Tat Ke Sector 

Then on 29th September, 2010 at 12:10 PM in Tat Ke Sector, we saw our first group of Tonkin snub-nosed monkeys. The local guide Quan Van Thiet, observed five animals including two adult males, three adult females and more animals behind dense foliage. This group likey  consists of two subgroups because two adult males were observed. If the subgroups have the same organization with an average size of 4-5 adults in a One-Male-Unit pattern, the number of individuals may be ten (or more).

Subsequently, three groups of Tonkin snub-nosed monkeys were observed in the Ban Bung Sector. The first group with a maximum of ten individuals including at least one infant was observed on four occasions. On two of those occasions the group was seen  foraging in association with a group of 20-25 stump-tailed macaques (Maccaca arctoides), the first time this behavior has been documented. The second Ban Bung group of Tonkin snub-nosed monkey was detected by vocalization in Pa Puc Area by a survey party on 2nd November, 2010 at 12:06 p.m. According to our estimates this group has from two to four individuals. A local guide, Nong Van Huan, observed two adults at 5:30 p.m. on 7th November, 2010. He thought that it was the same group we encountered on 2nd November but they were observed after five days at at second location so may represent a third group.

The field surveys in Tat Ke and Ban Bung Sector covered most of the potential habitats for Tonkin snub-nosed monkey. Risks to the animal are still considered great. Hunting stands out as the most serious threat in both sectors. During our survey in Tat Ke Sector, forest rangers confiscated one rifle from a local hunter. Photos and the coordinates of timber extraction sites and hunter campsites were recorded and reported to the Forestry Department. Habitat destruction was the second largest risk and is more severe in Ban Bung Sector than in Tat Ke. Lack of enforcement personnel is also a difficulty. The new hydropower dam has increased accessibility to the Nature Reserve creating another obstacle for forest protection. To date, one floating ranger station on the Gam River and another on the Nang River have been established to control the access by river.

To maximize the effectiveness of existing staff, we provided a technical training course for rangers and Community Patrol members of Na Hang Nature Reserve. Local forest rangers and CPG members were trained on conservation status and survey techniques for the Tonkin snub-nosed monkey. There was also training in the use of map, GPS, compass, records keeping and interview skills. Threats to TSNM and biodiversity of Na Hang Nature Reserve were discussed extensively to strengthen awareness of conservation for forest rangers and Community Patrol members.

 

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