Bola Batu Babirusa

Half deer, half pig

The animal with the strange-sounding name Bola Batu babirusa is a presumably extinct species of deer-pigs (Babyrousa)—a combination of the Indonesian words for Deer and Pig. Scientists disagree about whether the species found on the Indonesian island of Sulawesi is extinct or still alive, and whether it is even a separate species.

The Dutch paleontologist Dirk Albert Hooijer scientifically described the Bola Batu babirusa in 1950—initially, however, as a subspecies of Babyrousa babyrussa. At that time, B. babyrussa encompassed all deer-pigs, and a division into different species only took place later. Thus, the Bola Batu babirusa was recognized as a distinct species by biologists Colin Groves and Erik Meijaard in 2002.

Scientists now distinguish between four types: the Moluccan babirusa (Babyrousa babyrussa), the North Sulawesi babirusa (Babyrousa celebensis), the Togian babirusa (Babyrousa togeanensis) and the Bola Batu babirusa. All deer-pig species live exclusively on Sulawesi or the offshore islands and on the Sula Islands, an archipelago in Indonesia.

This division into four species, one of which is extinct, is according to the Handbook of the Mammals of the World Vol. 2 (2011) cannot be regarded as definitive, as genetic studies are still pending.

Bola Batu babirusa – fact sheet

scientific names	Babyrousa bolabatuensis, Babyrousa babyrussa bolabatuensis, (Babyrousa celebensis)
original distribution area	Sulawesi (Indonesia)
Time of extinction	unclear
Causes of extinction	Hunting, loss of habitat

Does the Bola Batu babirusa even exist?

The Bola Batu babirusa is only known from bone remains. It was named after the first location of its subfossil remains in the Bola Batu Cave. The cave where a jawbone and teeth were discovered is located in southern Sulawesi. That’s why experts assumed that the Bola Batu babirusa was also endemic there and is now extinct. The bones found come from the Holocene, the current period in geological history.

Several decades ago, a single deer-pig skull was discovered in the Kulawi Province in central Sulawesi and was attributed to the Bola Batu babirusa. Based on this find, Groves assumed in 1980 that there was one Article the trade magazine Zoological Mededelange that there is one existing population of Bola Batu babirusan in the central part of the island could give.

Afterwards, Groves, together with Meijaard, found similarities between the deer-pigs of Central Sulawesi and the Togian babirusa, which only occurs on the offshore islands. They therefore assumed that it was a previously undescribed taxon. A final taxonomic classification can only take place if more specimens are found, according to Groves and Meijaard.

Groves and Meijaard initially classified the first subfossil remains found as Bola Batu babirusa. However, they later classified the find as unclassifiable, as well as existing populations from East Sulawesi and the island of Buton. There are currently not enough specimens for further investigations. Due to these uncertainties, the IUCN provisionally considers the Bola Batu babirusa to be the same species as the North Sulawesi babirusa (B. celebensis).

Why would the Bola Batu Babirusa become extinct?

Deer-pigs and other pig species have been hunted and domesticated by humans since time immemorial. This is also evidenced by 40,000-year-old cave paintings on the island of Sulawesi found and possibly shows a deer-pigs.

However, domestication never really worked with deer-pigs because the animals have difficulty reproducing in human care. The IUCN estimates that there are just 4,000 deer-pigs left in the wild today. The International Organization for Conservation of Nature classifies the various species as ‘endangered’ and ‘endangered’.

Alastair A. Macdonald is in Ecology, Conservation and Management of Wild Pigs and Peccaries (2017) took a closer look at the dangers that deer-pigs are exposed to. The inhabitants of Sulawesi were (and still are) hunting the animals to sell the meat to Christian communities in the north. Some will too male deer-pigs killed for their teeth to sell them to Balinese traders. They in turn use these to make masks.

It also happens that deer-pigs accidentally caught in snare traps by Muslim hunters who are actually hunting for anoas (cattle native to Sulawesi). Since Muslim hunters view deer-pigs as vermin that poison their traps, they kill the animals and leave them to rot in the forest.

Deer-pigs live in tropical rainforests, but commercial deforestation and forest conversion and degradation destroyed more than 75% of forest areas. Also that one Loss of natural habitat could therefore have been a cause of the extinction of the Bola Batu babirusa. And if the Bola Batu babirusa still exists or does not represent a separate species, then it is certain that The number of deer-pigs in Sulawesi has declined sharply. The trend is decreasing, according to the IUCN.

The Bola Batu babirusa is not the only animal species that is believed to be extinct on Sulawesi. Also that one duck-billed buntingi, a fish of Lake Poso in the center of the island, and the bird species Sangihe dwarf kingfisher (Ceyx fallax sangirensis) from the offshore islands are probably affected.

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