The trio of critically endangered Delacour's langurs (voọc mông trắng) had been at a conservation center in Cuc Phuong National Park.

VnExpress reports that the langurs were moved from the center to the Trang An Scenic Landscape Complex in Ninh Binh Province in cooperation with Four Paws Viet, an animal welfare organization.

Trang An had been home to Delacour's langurs up until the 1990s, after which they were wiped out by poaching, Đỗ Văn Lập, deputy director of Cuc Phuong, told the news source. Conservationists hope that the release of the langurs into Trang An will help bring a wild population back to the area.

In 2000, a project focusing on endangered primates, including the Delacour's langur, was established in Cuc Phuong. In the decades since, the conservation initiative has rehabilitated and released hundreds of animals into the wild, including a number of langur and slow loris species.  

The news source adds that at least 30 more individual animals are expected to be re-wilded from Cuc Phuong over the next few years.

According to Fauna & Flora International, the Delacour's langur is endemic to Vietnam, meaning it is only found in the country, and only around 200 remain in the wild, with over half of that population living in the Van Long Nature Reserve in Ninh Binh.

As with many of Vietnam's native animal species, and particularly primates, the Delacour's langur has been decimated over the years by illegal hunting and habitat loss.

[Photo: A Delacour's langur/CIFOR]