September 30, Manas National Park : Eighteen captive-bred pygmy hogs have been released in the sprawling Manas National Park of Assam, India, by the Pygmy Hog Conservation Programme (PHCP), today. 

This is for the fourth time pygmy hogs have been reintroduced to Manas Park by the PHCP after successful releases in 2022, 2021 and 2020. This has now taken the total number of this Critically Endangered species released at this site up to 54, meaning the PHCP is well on its way to meet its target of 60 hogs released in Manas Park by 2025.

The programme, which is made up of founding partner Durrell Wildlife Conservation Trust, along with the IUCN/SSC Wild Pig Specialist Group, Assam Forest Department, Ministry of Environment and Forests, Government of India, and Ecosystems-India, with Aaranyak as delivery partner, has been working to bring this precious species back from the brink after it was previously thought to be extinct in the 1970s.

The PHCP has so far successfully bred and reintroduced 170 hogs in Assam, India, which, we are happy to say, for the first time since the reintroduction programme began, may now be outnumbered by their current global wild population.

The Pygmy Hog Conservation Programme

The Pygmy Hog Conservation Programme (PHCP) started its work in 1996, where two males and two females were captured from the Bansbari range of Manas National Park. The reintroduction of captive bred hogs to the wild began in 2008. Prior to releases in Manas National Park, the PHCP selected other appropriate grasslands in Assam for reintroductions of the pygmy hog. One site, Orang National Park, is located approximately 120km southeast of Manas, on the north riverside of the Brahmaputra River. The park is approximately 80km² and supports grassland, woodland and ‘mosaic’ habitat types, as well as charismatic species such as the tiger, elephant and rhino.

Fifty-nine pygmy hogs were released in Orang between 2011 and 2015. The reintroductions in Orang have been particularly successful as the population is now estimated to be 130 hogs. This is made even more exciting as the lifespan of a pygmy hog in the wild is around 7 years, so this population is likely to be made up of entirely wild born hogs.

Pygmy hogs are extremely shy and secretive in the wild, remain hidden in tall dense grass and rarely emerge in the open, which has made monitoring them at the reintroduction site in Orang National Park a challenge. 

The PHCP team of conservationists have worked through this by employing camera traps and undertaking sign surveys, where the team look for pygmy hog pellets, nests, foraging marks, and footprints. The pygmy hogs have been seen up to 2km away from the nearest release site, showing a healthy dispersal and exploration of the site by reintroduced and wild-born individuals.

PHCP Project Director, Dr. Parag Jyoti Deka said: “The results of the Orang camera trap and sign surveys show the real impact that our captive breeding and release programmes can have towards saving species from extinction. With the inspirational dedication of the Durrell team, and with the support of our partners Aaranyak and Assam Forest Department in Assam, we have been able to restore a self-sustaining population of pygmy hogs, bringing back an integral part of the ecosystem of the grasslands of Orang National Park. This has been achieved alongside an effective science-based programme of habitat restoration, benefiting not only the pygmy hog, but also other grassland specialist species.”

As part of its rewilding strategy, the PHCP will continue to maintain a population of around 80 captive hogs at its two centers in Assam and breed more hogs for release. The strategy for monitoring hogs after their release continues to develop.

 For this particular release the PHCP will be employing not only camera trap and sign surveys, but also carrying out a fourth year of radio-telemetry tracking on eight of the pygmy hogs, which will provide critical data about their behaviour after release and the habitat use of reintroduced hogs.

Manas Park contains some of the largest remaining grassland blocks in the sub-Himalayan grassland ecosystems. Manas Field Director, Rajen Choudhury, said, “I am happy to welcome the release of more pygmy hogs to their original home. It will boost the rewilding of Manas' grasslands and also bring back its glory. Manas National Park management is investing more in scientific management of the grassland. We hope this management will help in securing the future of the reintroduced pygmy hog and they will establish their home here. It will also help all the grassland associated species in Manas National Park, like the Bengal florican, hispid hare, hog deer and rhino.”

In the last three years when both Coronavirus and African Swine Fever in Assam have presented major challenges for the PHCP, the successful release of 54 hogs into Manas National Park is a landmark achievement and is a key step on the road to the establishment of a new sub-population of pygmy hogs in their historical home.

Dr. Bibhab Kumar Talukdar, CEO of Aaranyak - a key partner of the programme, added that, “Aaranyak is happy to continue to be a delivery partner of the Pygmy Hog Conservation Programme – an important species recovery programme. I am happy to learn that from the reintroduction of the pygmy hog in the recent past, it has established a population in Orang National Park. This result will encourage the entire conservation community to dedicate more towards species recovery. The continued reintroduction effort of the pygmy hog in Manas National Park will help not only in population building but also investing more in securing their home.”

Pygmy Hog Conservation Programme (PHCP)

In 1995, Durrell Wildlife Conservation Trust, Jersey, UK partnered with Forest Department, Government of Assam, IUCN, Wild Pig Specialist Group and Ministry of Environment, Forest and Climate changes, Govt. of India formed Pygmy Hog Conservation Programme (PHCP). Currently the project is being implemented with the PHCP’s key partner Aaranyak.

Until 2018, the PHCP was guided by the IUCN Species Action Plan (SAP) 1993, prepared by the WPSG. The revised SAP has been enacted with a long term vision till 2030.  The PHCP is guided by Durrell’s ‘Rewild Our World’ strategy with two plans which map out the programme until 2025, one for habitat and community activities in Manas NP and the second for the pygmy hog captive breeding and reintroduction programme. In order to achieve the programme’s vision of restoring pygmy hog populations in the wild and protecting their grassland habitat for the benefit of all threatened species and local communities, this plan is being implemented.

The pygmy hog

The pygmy hog (Porcula salvania) is the world’s smallest and rarest wild pig most threatened by extinction. It belongs to a unique genus that has no close relative. It stands about 25 cm from the ground and weighs 6 to 9 kg. It differs from young wild boars in having a rudimentary tail (2-3 cm) and more spindle-shaped body (hence its Assamese and Bodo names Takuri Bora and Oma Thakri; the more commonly used Nal Gahori is a misnomer as it does not prefer the Nal or Phragmites grass). It lives in small (4-8) groups that construct thatch ‘houses’ (nests) to live in, and not just to farrow like other pigs. The species was originally found in the narrow belt of tall alluvial grasslands that runs across the southern edge of the Himalayas in the Indian subcontinent.

Tall alluvial grass habitats, being very rich in nutrients, are highly suitable for cultivation and therefore came under significant pressures from expanding human populations, agriculture and uncontrolled harvesting; all of which caused disappearance of this highly sensitive species. Currently, indiscriminate grass burning, livestock grazing, commercial forestry operations and human encroachment are the greatest threats to this species, which has already been extirpated throughout the remainder of its known recent range in Assam and northern West Bengal.

Pygmy hog as an indicator species: Besides being a unique species and one of most endangered mammals of the world, the pygmy hog also happens to be a sensitive indicator of its habitat. The tall alluvial wet grassland belt just south of the Himalayan foothills is home of several other highly threatened species, such as the Bengal florican, hispid hare, eastern barasingha, and wild buffalo. The grassland is also used extensively by rhino, elephant, tiger, hog deer and a number of small animals such as endangered turtles. The project to save pygmy hog also gives us an opportunity to address the larger question about conservation and management of one of India's most biodiversity rich habitats. These wet grasslands also help in maintaining long term ecological and economic well-being of the region as they serve as buffer against floods in the rainy season while maintaining high groundwater levels in dry season, indirectly benefiting farming communities living in the fringe areas.