Palaeoenvironmental and zooarchaeological data generated by a project like SUNDASIA has the potential to help characterize longer-term trends in the biodiversity within Tràng An and comparable tropical limestone karst habitats. This includes responses to different scales of environmental and climatic change; considerations that are central in today’s conservation management planning (e.g. see O’Donnell et al. 2020; Rabett et al. 2017).

The project’s ambitions in this regard are aligned with UN Sustainable Development Goals (notably 6 & 15). Working with a number of stake-holders – including the Oxford University Museum of Natural History, IUCN, the Endangered Primate Rescue Center (EPRC), Cuc Phuong National Park and the Xuan Truong Enterprise, and others – SUNDASIA is helping to establish a more detailed picture of modern species biodiversity within Tràng An and to promote its future conservation.

Delacour’s langur (Trachypithecus delacouri) trial re-introduction to Tràng An 


Delacour’s langur (Trachypithecus delacouri) is a Vietnamese endemic primate categorised as ‘Critically Endangered’ on the IUCN Red List of Threatened Species and has been listed as one of ‘The World’s 25 Most Endangered Primates’. Its current distribution is restricted to a small number of karstic areas of northern Vietnam. The need to protect existing reserves and instigate new ones has been highlighted in the Vietnamese Government’s ’Urgent Conservation Action Plan for Primates in Vietnam to 2025, Vision 2030’ (May 2017, Decision 628 QD-TTg) and follows recommendations in the IUCN/SSC Primate Specialist Group UNEP Action Plan for Asian Primate Conservation: 1987-91.

Building on the success and ecotourism benefits of the first reintroduction effort of this species in the Van Long Nature Reserve (Elser et al. 2015), a collaborative venture between SUNDASIA, the Vietnam Primate Conservation Program, the Endangered Primate Rescue Centre (EPRC), Cuc Phuong National Park, the Tràng An Management Board, and Leipzig Zoo aimed to establish a trial population within the Tràng An World Heritage Site as a crucial step towards safeguarding the future of this species.

  • September 2017 and December 2018 – Two vegetation surveys were conducted by a SUNDASIA team, led by Shawn O’Donnell and Nguyen Thi Mai Huong, on a small forested island (1.5 hectares) approximately one kilometre northwest of the Tràng An Visitor Centre (following Nadler 2015; also see UNESCO State of Conservation Report 2017: 78-81; Rabett et al. 2019: 44-45).
  • February 2019 – A Global Impact Accelerator Award (GIAA) to SUNDASIA funded training in conservation practice for 62 local staff in Tràng An. This was organised and led by Tilo and Hien Nadler (IUCN Primate Specialist Group) and Bui Van Tuan (Green Viet, Danang NGO), with contributions from Bui Van Manh (Ninh Binh Department of Tourism), Mai Thanh Huyen (Ninh Binh Forest Protection Department) and Nguyen Van Linh (Van Long Nature Reserve) and hosted by the Tràng An Management Board (see Introduction Updates on this site).
  • April 2019 – A VTV2 television documentary feature on the Delacour’s langur was completed (funding: SUNDASIA GIAA grant).
  • July 2020 – The island release site in Tràng An was prepared and three guards employed by the Tràng An Management Board received a week of training at the EPRC on practices such as how to feed the animals for the short period in the cage and how to call the animals back after they have been released.
  • August 2020 – The initial release cage was set up on the island and three Delacour’s langur were transported there from the EPRC on 27th August.

1 cage transport 1

2 cage transport 2

3 cage set up

6 transferred langurs

3 langur transport

DSCN9103 - Copy

5 langurs tranferred

  • 28th August an official event and exhibition was convened at the Tràng An Visitor Centre to mark the transfer with guests from Ninh Binh Provincial People’s Committee, Forest Protection Department, TV-Hanoi, TV-Ninh Binh, and journalists from several newspapers. A poster exhibition accompanied the event (funding: SUNDASIA GIAA and AHRC/GCRF grants, and Four Paws Bear Sanctuary). This exhibition is now a fixture at the Visitor Centre.


7 prepared for the event

  • September 2020 – After settling in their new surroundings, the three langurs were released from the cage to range across the island, where they can be seen by passing tourist boats (following the successful Van Long Reserve model). The initial monitoring period of the trial is expected to be c. 12 months, involving the Tràng An and Van Long Management Boards, EPRC and Forest Protection Department.

Delacour's langurs on Langur Island



Vertebrate community monitoring

During the archaeological investigations by SUNDASIA at Hang Ang Noi, Tràng An in 2016 surface accumulations of small vertebrate remains were identified at the back of the cave comprising deadfall and regurgitated material from an owl roost. Located close to an arterial route through the World Heritage Property this site has the potential to provide a sensitive record of local environmental disturbance. Sample collection and analysis, led by Christopher Stimpson, is on-going (UNESCO State of Conservation Report 2017: 77-78).

Trail camera survey


Following discussion with stake-holders and collaborators, a trail-camera survey of vertebrate fauna, headed by Christopher Stimpson, took place in the property in 2017. Cameras were set in September and retrieved in November (UNESCO State of Conservation Report 2017: 76-77; Rabett et al. 2019: 38).

Entomology survey


Data obtained during a preliminary entomological transect survey undertaken in September 2016 are currently being analysed by colleagues at the Oxford University Museum of Natural History.

(Featured image: Delacour’s langur (Trachypithecus delacouri) in the Van Long Nature Reserve – image credit: C.M. Stimpson. Main text image credits: image 1 C.M. Stimpson;  images 2-11 courtesy of T. Nadler; image 12 Trang An Management Board; image 13 R. Rabett; image 14 T. Kahlert. All images reproduced with permission.)