The Pygmy Hog is the smallest and the rarest wild suid in the world. This species is dependent on early successional riverine communities, typically comprising dense tall grasslands, commonly referred to as 'thatchland', but which, in its pristine state, is intermixed with a wide variety of herbaceous plants and early colonizing shrubs and young trees (Oliver and Deb Roy 1993). There are many species of tall grasses, which dominate in different situations. The most important of these communities for Pygmy Hogs are those which tend to be dominated by Saccharum munja, S. spontaneum, S. bengalensis, Themeda villosa, Narenga porphyrocoma and Imperata cylindrical, which form characteristic associations of 1 to 4 m height, during secondary stages of the succession on well drained ground. These communities are not, therefore, maintained by prolonged inundation, though they may be maintained by periodic burning. However, as they also include some of the most commercially important thatching grasses, some of these areas (including many of those in protected areas) are harvested annually and virtually all of them are subject to wide-scale annual (in some areas, twice-annual) burning. Although it has been suggested by ecologists that any burning be conducted at the beginning of the dry season (in December or early January) in alternate blocks (demarcated by fire-lines) and only once in 2-3 years, most of the grasslands continue to be burnt every year in the dry season, which deleteriously affects their floral and faunal diversity. It has been recognised that some amount of ?early? burning may be required in order to preclude the possibility of later, uncontrolled 'hot' burns, which are far more destructive, and possibly to delay natural succession of the grasslands in protected areas. However, early burning also may deprive hogs and other grassland dependant species of cover and other resources for a longer period prior to the regrowth of vegetation and has the same consequences of dramatically reducing floral and faunal diversity.

Red List Category

Red List Criteria

Version

2008

Narayan, G., Deka, P. & Oliver, W.

Leus, K. & Oliver, W. ( Pig, Peccary & Hippo Red List Authority)

Justification

History

• 1996
  Critically Endangered
• 1994
  Endangered
  (Groombridge 1994)
• 1990
  Endangered
  (IUCN 1990)
• 1988
  Endangered
  (IUCN Conservation Monitoring Centre 1988)
• 1986
  Endangered
  (IUCN Conservation Monitoring Centre 1986)

Today, this species is at the brink of extinction, as only a few isolated and small populations survive in the wild. In fact, the only viable population of the species, with a few hundred individuals, exists in small grassland pockets of Manas National Park (500 km²) and an adjacent reserve forest in the Manas Tiger Reserve and nowhere else in the world (Narayan and Deka 2002). Sixteen captive-bred Pygmy Hogs were released in Sonai Rupai Wildlife Sanctuary in May 2008 and similar reintroductions have been planned in Nameri and Orang National Parks of Assam. There are about 75 animals in captivity in northwestern Assam.

Decreasing

The main threats to survival of Pygmy Hog are loss and degradation of habitat due to human settlements, agricultural encroachments, dry-season burning, livestock grazing, commercial forestry and flood control schemes; the latter as a result of the disruption of natural successions and the replacements of former grasslands by later stage communities or other developments. In Assam, as elsewhere, most former habitat has been lost to settlements and agriculture following the rapid expansion of the human population (Oliver, 1980, 1981, 1989; Oliver and Deb Roy, 1993). Some management practices, such as planting of trees in the grasslands and indiscriminate use of fire to create openings and to promote fresh growth of grass, have caused extensive damage to the habitats the authorities intend to protect (Narayan and Deka 2002). A combination of these factors has almost certainly resulted in the loss of all of the small populations of these animals in the reserve forests of north-western Assam. These losses strongly reinforced the overwhelming importance of the largest and, by the early to mid-1980's, only known surviving population in the Manas (Oliver, 1981, 1989; Oliver and Deb Roy 1993).

Hunting for wild meat by tribes was not considered a major problem in the past but is now threatening the remnant populations (Narayan and Deka 2002). The survival of Pygmy Hogs is closely linked to the existence of the tall, wet grasslands of the region which, besides being a highly threatened habitat itself, is also crucial for survival of a number endangered species such as Indian rhinoceros (Rhinoceros unicornis), tiger (Panthera tigris), swamp deer (Cervus duvauceli), wild buffalo (Bubalus arnee), hispid hare (Caprolagus hispidus), Bengal florican (Eupodotis bengalensis), swamp francolin (Francolinus gularis) and some rare turtles and terrapins.

The Pygmy Hog Conservation Programme (PHCP) is a broad-based research and conservation programme for this highly threatened species and its equally endangered habitats (Narayan and Deka 2002, Narayan 2006). It is being conducted under the aegis of a formal International Agreement, that was originally signed at New Delhi in 1995 and later renewed as a Memorandum of Understanding in 2001, between IUCN SSC Pigs Peccaries and Hippos Specialist Group, Durrell Wildlife Conservation Trust (DWCT), the Forest Department, Government of Assam, and the Ministry of Environment and Forests, Government of India. A local governing body consisting of representatives of the four signatories and some Indian experts has been constituted to provide guidance to the Programme. The implementation of this agreement, the first of its kind in India, is being undertaken by PHCP and the local partner organisation, EcoSystems-India, with funds provided by DWCT, with assistance from the European Union, Darwin Initiative (UK government), Assam Valley Wildlife Society, Zoological Society for the Conservation of Species and Populations (ZGAP), and various other sources. The primary aim of this collaborative programme is conservation of the Pygmy Hogs and other endangered species of tall grasslands of the region through field research, captive breeding and re-introduction after adequate restoration of degraded former habitats. One of the main objectives of the Programme was to establish a well structured conservation breeding project for pygmy hogs as an insurance against the possible early extinction of the species in the wild and as a source of animals for re-introduction projects. In 1996, six (2 male, 4 female) wild hogs were caught from Manas National Park and transferred to a custom-built research and breeding centre built at Basistha near Guwahati, the capital of Assam. Five more hogs were caught and released at the capture site after fitting three males and a female with radio harness for radio-telemetry studies. The hog population kept in captivity almost doubled in 1997 from 18 to 35 through planned breeding. Between 1998 and 2002, several more hogs were born in captivity and a rescued wild hog was added to the captive population, taking it to over 75 animals which constituted over 1200% increase in 6 years. Although two more enclosures and a quarantine facility were constructed at Basistha, the unanticipated and rapid increase in the captive population created accommodation problems, forcing the programme to restrict breeding in captivity. Subsequently, a much larger facility was established at Potasali near Nameri National Park in Assam. This facility includes four holding enclosures and four pre-release enclosures with near natural habitat, where hogs earmarked for reintroduction are reared. Since the animals at Basistha Centre are the only captive pygmy hogs in the world, the second centre is also an insurance against any catastrophe at the present location. Once the Potasali pre-release enclosures were ready and the habitat at one of the release sites became reasonably suitable, the hogs were allowed to breed again.

Surveys to locate possible release sites in Assam were carried out, as the rapidly increasing captive population necessitated transfer of some of these pygmy hog back to where they belonged. Two potential re-introduction sites were identified in Sonai Rupai Wildlife Sanctuary and Nameri National Park, both in Sonitpur district of Assam bordering Bhutan and Arunachal Pradesh. Habitat management and protection regimes at the potential release sites were assessed in consultation with authorities and recommendations for restoration and scientific management were given. The management authorities are trying to implement the recommendations with limited auccess. The habitat in a part of Orang National Park was also found suitable, but in absence of any reliable record of the species formerly occurring in this area, further evaluation is considered necessary.

The actual release of hogs was delayed initially due to security problems and later due to presence of factors that were responsible for disappearance of the hogs at the potential reintroduction sites. Once the some of the recommendations were implemented at one of the sites (Sonai Rupai), preparations for soft release were started. In 2007, 23 babies were produced at Basistha. Three social groups comprising 16 (7 male, 9 female) hogs, including 10 yearlings, were transferred from Basistha to Potasali pre-release enclosures in December 2007. They were kept in the pre-release enclosures under minimum human contact. Each of these enclosures are 2,400 to 3,200 m² in size and capable of meeting most of the food requirements of a group of 5-6 hogs. These hogs began to behave like wild animals within a few weeks and did not come close even to their keepers except in an area where they were offered a few morsels of their favourite food. They were shifted to a release enclosure in Sonai Rupai after five months, and were given access to go to the wild after about two weeks. Unfortunately, the radio telemetry studies on these hogs could not be done as the radio harness fitted on six of them while they were in pre-release caused injuries when they moved rapidly through very dense grass. The released hogs will be monitored through indirect means (droppings, nests) and by observing them at bait stations.

Community conservation initiatives and awareness campaign have been started in the fringe villages of Manas, Nameri and Sonai Rupai as it is almost impossible to save the species without the cooperation of the local population. Capacity building and training programmes are also being carried out for the frontline protection staff in the above protected areas.

This species is listed on CITES Appendix I (as Sus salvanius).