|Scientific Name:||Sus verrucosus|
|Species Authority:||Boie, 1832|
|Infra-specific Taxa Assessed:|
|Taxonomic Notes:||Sus verrucosus originally had three subspecies, the nominal subspecies on Java, S. v. olivieri on the island of Madura, which is now thought the be extinct (Blouch 1998), and S. v. blouchi of Bawean Island. S. v. blouchi was upgraded to full species by Groves and Grubb (2011), but pending additional genetic study it is for now maintained as a subspecies.|
|Red List Category & Criteria:||Endangered A2cd ver 3.1|
|Assessor(s):||Semiadi, G., Rademaker, M. & Meijaard, E.|
Listed as Endangered because of a serious population decline, estimated to be more than 50% over the last three generations (approximately 18 years), primarily caused by a decline in suitable habitat, especially of stands of teak Tectona grandis forest or similar forest plantations, and by high hunting pressure.
|Previously published Red List assessments:|
|Range Description:||The Javan Warty Pig is endemic to Indonesia. Historically the species was present on Java, Madura Island and Bawean Islands; now the species is very fragmented into small pockets of suitable habitat (Grubb 2005). It is extinct on Madura (Semiadi and Meijaard 2006). Two subspecies are recognized. The nominate form, Sus v. verrucosus, occurs on Java (and formerly Madura) where it is sympatric with Sus scrofa vittatus. The second subspecies, S. v. blouchi is confined to Bawean Island in the Java Sea where it is also sympatric with Sus scrofa vittatus. This species was widespread on Java as recently as 1982 (Semiadi and Meijaard 2006), but is now absent from most of the island, and is surviving only in highly fragmented populations.|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The species occurs in at least 10 isolated areas on mainland Java, although some additional, probably very small populations, might survive elsewhere (Semiadi and Meijaard 2006). For example, recently another pocket area was found in Banjar (West Java), though intensive survey work is needed to establish the size of the area and the population (Semiadi 2007 unpubl. data). There are no estimates of overall population size, but the species has shown a rapid population decline in recent decades. Compared to a survey conducted in 1982, 17 of the 32 (53%) populations are extinct or have dropped to low encounter rate levels (Semiadi and Meijaard 2006).|
Semiadi and Meijaard (2004), as a result of widespread interviews, reported the species from the following areas:
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||The species occurs both in cultivated landscapes and in teak forest plantations (Semiadi and Meijaard 2006), with the highest density thought to occur between Semarang and Surabaya on both sides of the border between the provinces of Central and East Java. Recent data (Semiadi 2008, unpubl data) indicate that near Banjar (West Java) there is a possibility of significant numbers of animals in a fragmented teak forest and mixed local and agricultural forest.|
The vegetation in which they occur is dominated by mixed age teak (Tectona grandis) plantations interspersed with lalang grasslands (Imperata cylindrical), brush and patches of secondary forest. This apparently provides an optimum habitat for this species. Javan Warty Pigs are everywhere restricted to elevations below about 800 m. The reasons for this are not known, but it might be due to their being unable to tolerate low temperatures (Blouch 1993). They evidently prefer secondary or disturbed forests, though they are also often found near the coasts in remnant patches of mangrove and swamp forest such as in Pangandaran (West Java) and Cilacap (Central Java). They are rare in the few remaining lowland primary forests, and in areas with high human populations where otherwise suitable habitat is fragmented and surrounded by agricultural land. However, they do feed on crops, making nocturnal raids on fields of corn and cassava and, in common with Sus scrofa, the species is widely persecuted for such depredations (Blouch 1988).
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Generation Length (years):||6|
|Use and Trade:||The species is widely hunted as an agricultural pest, also because hunters do no differentiate it from the sympatric Sus scrofa (Semiadi and Meijaard 2006).|
|Major Threat(s):||Semiadi and Meijaard (2006) hypothesized that the population decline observed in this species is primarily caused by a decline in suitable habitat, especially of stands of teak Tectona grandis forest or similar forest plantations, and by high hunting pressure. With the imposed regulation by the government for teak plantation forests to adopt a mixed agriculture system (agroforestry system) by cultivating agricultural products in between the young teak plantations, teak plantation forests become suitable Sus verrucosus habitat. However, a 35-50 year cycle of teak forest harvest remains a threat for the availability of this habitat. In any case, there is extensive illegal logging of teak plantations, no doubt to the detriment of S. verrucosus. These animals are killed both by sport hunters and by farmers protecting their crops (Blouch 1995). Many animals are killed by poisoning (Semiadi and Meijaard, 2006). As yet unpublished reports of the recent dramatic reduction in numbers, possibly resulting in the extirpation, of S. v. blouchi, on Bawean Island have been attributed to correspondingly increased hunting pressure following the recent settlement of Christian immigrants from Sumatra; these animals having been previously left largely unharmed by the predominantly Moslem inhabitants. Competition from and hybridization with the Eurasian wild pig, Sus scrofa has been speculated as a further threat to S. verrucosus, especially in areas where human induced habitat changes have favoured S. scrofa, though there is little direct evidence for this and the two species evidently occur sympatrically in some areas, including Bawean Island.|
Javan warty pigs are poorly represented in existing protected areas. Creation of three new nature reserves and expansion of two existing reserves of importance to the taxon were recommended (Blouch 1993). In addition, surveys of the extent of market hunting should be undertaken with the objective of formulating means to regulate or eliminate the practice, and ecological research and investigation on crop damage should be conducted. Captive animals need to be administered under a properly structured plan for the long term genetic and demographic benefit of the species.
A captive breeding project of S. v. verrucosus is underway and it is breeding the species successfully. A second breeding program is under development. Breeding is so successful that identification of a suitable release site has become urgent. Very few people on mainland Java, however, would gladly welcome releases of the species in their neighbourhood. Suitable release sites therefore need to be identified in well managed protected areas or offshore islands where no people live.
Blouch, R.A. 1988. Ecology and conservation of the Javan Warty Pig Sus Verrucosus Muller,1840. Biological Conservation 43: 295-307.
Blouch, R.A. 1993. The Javan warty pig (Sus verrucosus). In: W L.R. Oliver (ed.), Pigs, Peccaries, and Hippos: Status Survey and Conservation Action Plan, IUCN, Gland, Switzerland.
Blouch, R.A. 1995. Conservation and research priorities for threatened suids of south and southeast Asia. Ibex - Journal of Mountain Ecology 3: 21-25.
Groves, C. P. and Grubb, P. 2011. Ungulate Taxonomy. Johns Hopkins University Press, Baltimore, Maryland.
Grubb, P. 2005. Artiodactyla. In: D.E. Wilson and D.M. Reeder (eds), Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed), pp. 637-722. Johns Hopkins University Press, Baltimore, USA.
IUCN. 2016. The IUCN Red List of Threatened Species. Version 2016-1. Available at: www.iucnredlist.org. (Accessed: 30 June 2016).
Semiadi, G. and Meijaard, E. 2004. Survey of the Javan Warty Pig (Sus verrucosus) on Java and Bawean Island. Pusat Penelitian Biologi-LIPI and IUCN/SSC Pigs, Peccaries and Hippos Specialist Group, Bogor, Indonesia.
Semiadi, G. and Meijaard, E. 2006. Declining populations of the Javan warty pig Sus verrucosus. Oryx 40: 50-56.
|Citation:||Semiadi, G., Rademaker, M. & Meijaard, E. 2016. Sus verrucosus. The IUCN Red List of Threatened Species 2016: e.T21174A44139369.Downloaded on 28 October 2016.|
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