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Cat Ba Island


Conservation benefit: Relocation of female Cat Ba langurs

Date Approved: 02.2007

Since 2000, the Cat Ba langur has been one of the world’s 25 most endangered primates (Conservation International and IUCN/SSC Primate Specialist Group). There are few langurs, and their range is restricted. Illegal hunting caused the population to plummet from about 2500-2800 individuals in the 1960s to a mere 53 individuals by 2000.

In 2002, Seacology began supporting a langur-guarding program. The program, instituted by the Zoological Society for the Conservation of Species and Populations, enlisted local residents to protect langurs from poachers. Since then, the langur population has increased. There are now 65 individuals, but the status of this species is extremely critical.

The remaining langur population is fragmented into seven isolated groups, four of which are all-female. Because the groups are so isolated, individuals can’t move from one to another. The only solution is to move some animals from Cat Ba Island to the langur sanctuary run by the Cat Ba Langur Conservation Project. Three females on a small offshore island are the first target for relocation. They cannot get back to the main island on their own because the mangrove forests between the main and offshore islands were destroyed. To help the Cat Ba langur population continue to grow, Seacology will help fund the relocation of these isolated females.

Project Updates

March 2015

The Cat Ba langur is still one of the most endangered primates in the world, but the population is slowly increasing and now numbers about 68. Langur hunting has completely stopped. Local “Langur Guards” prevent people from entering langur areas and disturbing the animals, and educate people on the importance of the langurs and overall environmental health.

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November 2012

The two isolated females were successfully relocated. No animals were injured during the process, and the females have since been observed joining langur groups and mating with males. In addition, languar project scientists got six months’ of tracking data from the females’ GPS radio collars.

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June 2011

Regular trips to the catching site of the langurs took place to check the equipment already fixed at the cave entrance and to plan the remaining steps for the relocation. Because the rainy season started much earlier than expected, the relocation had to be postponed to the beginning of the next dry season.

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January 2011

A Seacology expedition visited the project in November 2010. The group visited a floating ranger station, as well as one of the rangers in a remote part of Cat Ba Island. The relocation will likely take place within the next month. It is to be the first wildlife relocation to be attempted in Vietnam in several years. If the langurs cannot be lured out of their cave, the animals will be darted with tranquilizers.

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June 2010

The master plan and risk assessment have been translated and submitted to the local authorities, after which meetings were held with the Ministry for Agriculture and Rural Development in Hanoi and with the Peoples Committee in Hai Phong. Both meetings went extremely well and the project has finally received all the necessary support from all the involved local authorities. Implementation of the master plan will be the next step.

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November 2009

In September, the CBLCP finalized a risk assessment for the translocation plan. The master plan will be finished in this month. The next steps will involve the translation and the delivery of these documents to the authorities and the subsequent discussion to finally agree on the entire translocation plan.

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August 2009

The catching net has been attached to the sleeping cave, and the project leaders are waiting for the langurs to access it – unfortunately, they rarely do so during the rainy season. Collars for the relocated langurs will also be ordered which will include both VHF and GPS tracking and a drop-off system for when the project is completed and the langurs have been successfully relocated.

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June 2009

As of April 2009, after fixing a rope and a test net at the cave, one Vietnamese bachelor student spent several weeks at the catching site to monitor the reaction of the langurs to the equipment, to collect data about home range size and with what frequency the langurs use the cave as a sleeping place. It was observed that the langurs accepted the equipment, even using it to access the cave. A design for the catching net was finalized by the technical staff of Zoo Muenster, and the equipment was transferred to Vietnam. The next step will be to fix the first parts of this equipment at the cave before the rainy season starts. In addition to preparing the catching site, several trips were organized to study various release sites in the sanctuary to make sure that the release will not be too close to other langur or macaque groups.

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May 2008

In 2007 project leaders assessed the habitat use and migration routes to determine suitable sites for catching and relocation. The best possible site for capture was determined to be a sleeping cave 40 feet above the forest floor. In early 2008 staff blocked off small niches in the cave for langur and human safety during the eventual capture. Plans for mid-2008 include continuing an assessment of the langurs’ response to staff activity and climbing equipment at the cave to determine the best method of capture.

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October 2007

Project coordinator Dr. Rosi Stenke and her colleagues are assessing the habitat use and migration routes to determine suitable sites for catching and relocation. They are scheduled to begin relocation in October 2007.

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