The present range of Sus salvanius (commonly known as the pygmy hog) is found only in the reserve forest belts of the Manas Wildlife Sanctuary and the Barnadi Wildlife Sanctuary in northwestern Assam, India. However, they were once found in throughout northern India, Bhutan, and Nepal.
(Macdonald 1999; Massacot 2000)
Biogeographic Regions: oriental (Native )
India, Nepal, Bhutan, Sikkim
Sus salvanius is the smallest suid known. Adult males are on average 65 cm long (including the head), and 25 cm tall (to the shoulder). Females are only slighly smaller. Males average 8.5 kg in weight. Their coats have blackish-brown bristles over gray-brown skin and they have no facial warts. Both sexes have a tail that is approximatly 3 cm long and females have three pairs of mammae.
(WWF 1997; Macdonald 1999)
Range mass: 0 to 0 kg.
Average mass: 8 kg.
Habitat and Ecology
Pygmy hogs live in tall, dense grasslands that have a mixture of shrubs and trees. Within their home range of approximately 25 hectares (61 acres), family groups live in high dome-shaped nests made of grass and other vegetation.
This species once occupied parts of India, Bhutann and Nepal, however today they are restricted to northwest Assam in India. Their decline is believed to be caused by elimination of their habitat through human settlement, overgrazing of livestock, commercial forestry, flood control projects and agricultural encroachment. In addition, the grassland habitat is periodically burned during the dry season by Forest Deparment personnel or by herdsman and thatch collectors, leaving no cover and thus increasing vulnerability to hunters from neighboring villages.
(Sanyal 1994; Massicot 2000)
Terrestrial Biomes: savanna or grassland
Pygmy hogs have well developed teeth, with upturned canines and molars with rounded cusps. This allows them to enjoy an omnivorous diet. They feed primarily on roots, tubers and other vegetative food as well as insects, eggs, young birds, and reptiles. Foraging occurs for approximately 6 to 10 hours a day, pausing midday to escape the heat.
(Chung 1997; WWF 1997; Huffman 1999; Massicot 2000)
Life History and Behavior
Status: wild: 7.5 years.
Status: wild: 12.0 years.
Lifespan, longevity, and ageing
Reproduction is strongly seasonal, and the birth peak coincides with the monsoon in late April and May. Gestation is approximately 100 days and litters range from 2 to 6 young, but are usually 3 to 4 young. Sus salvanius reaches sexual maturity at 13 to 33 months and may live 10 to 12 years in the wild.
(Huffman 1999; Massicot 2000)
Average birth mass: 191.5 g.
Average gestation period: 108 days.
Average number of offspring: 3.
Average age at sexual or reproductive maturity (male)
Sex: male: 700 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 700 days.
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1996Critically Endangered
- 1994Endangered(Groombridge 1994)
- 1990Endangered(IUCN 1990)
- 1988Endangered(IUCN Conservation Monitoring Centre 1988)
- 1986Endangered(IUCN Conservation Monitoring Centre 1986)
Date Listed: 06/02/1970
Lead Region: Foreign (Region 10)
Where Listed: India, Nepal, Bhutan, Sikkim
Population location: India, Nepal, Bhutan, Sikkim
Listing status: E
For most current information and documents related to the conservation status and management of Sus salvanius , see its USFWS Species Profile
Sus salvanius was placed in the Endangered category according to IUCN in 1960. The species remained Endangered until 1996 when it was placed in the Critically Endangered category. In 1970 it was estimated that there were less than 150 pygmy hogs living in the wild. Currently Sus salvanius is protected by Schedule 1 of the Indian Wildlife (Protection) Act. In addition, a "three-point" Action Plan was agreed upon by the Indian Central Government, and the IUCN/SSC Pigs and Peccaries Specialist Group in 1987. This plan includes conducting field surveys on the remaining wild populations and assessing areas for future reintroduction of captive bred animals.
Pygmy hogs are listed under CITES Appendix I.
(WWF 1997; Massicot 2000)
CITES: appendix i
IUCN Red List of Threatened Species: critically endangered
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.
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 mÂ² 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).
Relevance to Humans and Ecosystems
Economic Importance for Humans: Negative
There is no information available that indicates Sus salvanius adversely affects humans.
Economic Importance for Humans: Positive
Sus salvanius has been over-hunted, so at one point it is likely that they provided a source of food for local hunters, and possibly income if the people sold the meat. There is no information available that speaks directly about Sus salvanius positively benefiting humans.
|This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (February 2008)|
The pygmy hog (Porcula salvania) is an endangered species of small wild pig, previously spread across India, Nepal, and Bhutan, but now only found in Assam. The current world population is about 150 individuals or fewer. Recent conservation measures have improved the prospects of survival in the wild of this critically endangered species.
Description and biology
They are about 55 to 71 cm long and stand at 20–30 cm (7.9-11.8 in), with a tail of 2.5 cm (1 in). They weigh 6.6-11.8 kg (14.5-26 lbs). Their skin is dark brownish-black and the hair is dark. Piglets are born grayish-pink, becoming brown with yellow stripes along the body length. Their heads are sharply tapered and they have a slight crest of hair on their foreheads and on the back of their necks. Adult males have the upper canines visible on the sides of their mouths. They live for about eight years, becoming sexually mature at one to two years old. They breed seasonally before the monsoons giving birth to a litter of three to six after a gestation of 100 days. In the wild, they make small nests by digging a small trench and lining it with vegetation. During the heat of the day, they stay within these nests. They feed on roots, tubers, insects, rodents, and small reptiles.
Taxonomy and systematics
The species was first described as the only member of the genus Porcula, but was then regarded as the closest relative of the Eurasian pig Sus scrofa and named Sus salvanius.  New genetic analysis of a large section of mitochondrial DNA supports the original classification of the pygmy hog as a unique genus. The resurrection of the original genus status and the species name Porcula salvania has been adopted by GenBank. The species name salvania is after the sal forests where it was found.
The pygmy hog is the sole representative of Porcula, making the conservation of this critically endangered species even more important, as its extinction would result in the loss of a unique evolutionary branch of pigs. They used to be widespread in the tall, wet grasslands in the southern Himalayan foothills from Uttar Pradesh to Assam, through Nepal and north Bengal. However, human encroachment has largely destroyed the natural habitat of the pygmy hog by development, agriculture, domestic grazing, and deliberate fires. Only one viable population remains in the Manas Tiger Reserve, but even there, threats due to livestock grazing, poaching, fire, and tigers persist. The total wild population has been estimated as less than 150 animals and the species is listed as "critically endangered".  Their rarity contrasts greatly with the massive population of wild boars (Sus scrofa) in India.
Conservation of the species has been hampered by the lack of public support, unlike that for charismatic South Asian mammals such as the Bengal tiger or Indian rhinoceros. Local political unrest in the area has also severely hampered effective conservation efforts, but these conflicts have now ceased.
Pygmy hogs were exhibited in the zoos of London and Berlin in the 19th century. However, this captivity was not aimed at conservation, and none of the captive populations survived. Zürich Zoo exhibited pygmy hogs from 1976 to 1978, but all females died. The success of captive breeding dramatically increased after the Pygmy Hog Conservation Programme (PHCP) was established in 1995. The PHCP was established under the umbrella of a formal 'International Conservation Management and Research Agreement' by the Durrell Wildlife Conservation Trust, the IUCN's Pigs, Peccaries and Hippo Specialist Group, the Forest Department, Government of Assam, and the Ministry of Environment and Forests, Government of India. Durrell Wildlife Conservation Trust has launched a comprehensive conservation strategy including field status surveys of pygmy hogs and their habitats, behavioural studies, personnel training, local community awareness and assistance programmes, and the establishment of a highly successful captive-breeding programme at the Pygmy Hog Research and Breeding Centre in Assam. Active habitat management has been established and a reintroduction programme has now been launched. (Narayan, 2006).
- Narayan, G., Deka, P. & Oliver, W. (2008). Porcula salvania. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 5 April 2009. Database entry includes a brief justification of why this species is of critically endangered.
- (Hodgson, 1847)
- (Oliver, 1980; Oliver & Deb Roy, 1993)
- (Funk et al., 2007).
- Horsfield, Thomas 1849. Brief Notice of several Mammalia and Birds discovered by B. H. Hodgson, Esq., in Upper India. Annals of the Magazine of Natural History. Volume 3: 202 Scanned text
- Garson JG (1883). "Notes on the anatomy of Sus salvanius (PorcuIa salvania, Hodgson). Part 1. External characters and visceral anatomy". Proceedings of the Zoological Society of London: 413–418.
- (Oliver, 1980; Oliver & Deb Roy, 1993; Pigs, Peccaries and Hippos Status Survey and Action Plan, 1993; Narayan, 2006).
- Oliver, William L. R. (1980). The Pigmy Hog: the Biology and Conservation of the Pigmy Hog, Sus (Porcula) salvanius, and the Hispid Hare, Caprolagus hispidus. Special Scientific Report No 1. Jersey Wildlife Preservation Trust.
- Oliver, William L. R., and Sanjoy Deb Roy (1993). The Pigmy Hog (Sus salvanius) - Chapter 5.3. IN: IUCN/SSC Pigs and Peccaries Specialist Group & IUCN/SSC Hippo Specialist Group. Pigs, Peccaries and Hippos Status Survey and Action Plan.
- Narayan, Goutam (2006). Pygmy Hog Conservation Programme—an update. Suiform Soundings, PPHSG Newsletter, Volume 6, Pages 14–15.
- Funk, Stephan M., Sunil Kumar Verma, Greger Larson, Kasturi Prasad, Lalji Singh, Goutam Narayan and John E. Fa (2007). The pygmy hog is a unique genus: 19th century taxonomists got it right first time round. Molecular Phylogenetics and Evolution, Volume 45, Pages 427-436.