Guwahati, May 31: The Pygmy Hog Conservation Programme is focusing on Bornadi wildlife sanctuary in Udalguri district to build up a strong population of the critically endangered animal.

Fourteen hogs have been released at the sanctuary, of which eight, three males and five females, were released on Monday. Last year, six hogs were released. The hogs were last seen in 1993.

This programme is a joint effort of the Durrell Wildlife Conservation Trust, IUCN Wild Pig Specialist Group, state forest department and the ministry of forest and environment and Eco Systems, India, an NGO.

The Durrell Wildlife Conservation Trust was founded by author and wildlife activist Gerald Durrell in 1999 as a charitable institution, with the dodo as its symbol.

The total area of the sanctuary is 2,621 hectares, of which grasslands comprise 500 hectares and 400 hectares have been encroached upon. The sanctuary is located on the foothills of Bhutan.

A programme official said the plan was to release around 35 hogs at Bornadi in the next four years. "A population of around 100 will be a good base for the conservation of hogs," the official said.

"Durrell and our Pygmy Hog Conservation Programme partners are building on our experience and teamwork of over 20 years to save this species from extinction. The joint efforts provide special moments like releasing pygmy hogs back into the wild. This displays the strength of our partnership and conservation methods. Bornadi will be our focus for the next four years and our work will continue to support and develop populations of hogs," Daniel Craven, a volunteer manager of the Durrell Wildlife Conservation Trust, told The Telegraph.

"We are trying our best to maintain the grasslands at the sanctuary for the survival of the pygmy hog," an official said.

The sanctuary is named after the Bornadi river, which flows along its western border. It is a part of the Manas tiger reserve, along with the Khalingduar reserve forest, and provides an excellent corridor for the movement of wild elephants upto Manas. More than 214 species of birds and 135 species of butterflies have be-en recorded at the sanctuary.

The survival of pygmy hogs is closely linked to the existence of the grasslands, which are a threatened habitat.