13 Javan Warty Pig

The Javan warty pig (Sus verrucosus) apparently has never been domesticated, but it has been a resource for hunting peoples for centuries. Now, however, the human population in its native region is predominantly Moslem, and all pigs are widely regarded as agricultural pests. Increasing numbers of them are poisoned each year.

Appearance and Size

The Javan warty pig can be up to 1.35 m long and 0.9 m tall. Mature males usually weigh between 80 and 120 kg; females are only half that weight - an unusually dramatic example of sexual dimorphism. The animal has a markedly elongated face with large warts, particularly the infraorbital wart and the smaller preorbital and mandibular warts. Body hairs can be black, red, or yellow, with black tips.

Distribution

This species is found only on the Indonesian islands of Java and Bawean. It was formerly found on Madura as well, but because of deforestation it is now thought to be extinct there. Two extant subspecies are recognized. The nominate one, Sus verrucosus verrucosus, occurs on mainland Java. The second, Sus verrucosus blouchi, a smaller animal, has recently been described on Bawean.

Status

For years it was thought that the Javan warty pig was extinct in the wild, but in October 1981 a herd was found in a small area on Mount Penanggungan in East Java. This population may prove to be substantial, and there is reason to hope that other populations can be found. Overall, however, it is clear that the Javan warty pig is endangered and declining in numbers. In many areas the animals are subjected to uncontrolled poisoning and hunting.

Five new reserves have recently been proposed to protect the animal in a variety of habitats because it is not found in appreciable numbers in any of Java's nature reserves.

The Bawean subspecies is believed to be relatively secure since the establishment of a large reserve.

A breeding colony of 12 Javan warty pigs at the Surabaya Zoo includes 5 young ones born in captivity.

Habitat and Environment

Habitats of the Javan warty pig appear to be confined to elevations below about 800 m. The animals prefer relatively large expanses of grassland or secondary vegetation, where human population is sparse.

FIGURE

 

Biology

The piglets can be born throughout the year; in one study of 8 sows the litter size ranged from 2 to 8, with a mean of 5.

The (diploid) chromosome number has been found to be 38, the same as that of the common pig. Hybridization between these species is thought to occur in the wild, but apparently not with enough frequency to contaminate the Javan warty pig gene pool.

Behavior

Unreported.

Uses

These are omnivorous, adaptable animals that might make useful domesticates.

Potential Advantages

The small size of the sows could make this species particularly appropriate for households or smallholder farms. The animal's genetic "distance" from the domestic pig may make it a useful generator of hybrid vigor in crossbreeds. It could have particular value because its meat is much leaner than pork from the common pig.

Limitations

The numbers in the wild are now too few to permit any cropping.

 

Research and Conservation Needs

Efforts should be directed towards locating and breeding up the Javan warty pig populations that still exist. An immediate need is to isolate pure populations in reserves because it is essential to protect the animal from crossbreeding with other species. In addition, current specimens in zoos should be cataloged and a breeding program established. Other captive breeding colonies should also be started.

It is important to determine the genetic differences between the Javan warty pig and the common pig, as well as the levels of existing hybridization between them. It is also necessary to determine what variation in karyotype may exist within the populations.

Basic ecological and behavioral studies are needed, as well as studies of the dietary requirements, growth rates, and nutritional physiology of captive specimens. The reproductive biology of the animal should be studied, and the possibility of crossbreeding it with other Sus species should be examined under controlled conditions.

The Javan warty pig's potential for local meat production should be evaluated. The benefit to rural people of converting an agricultural pest into a profitable source of income should be explored within the local religious context.

FIGURE