- Bawean warty pigs (Sus blouchi) are found only on the island of Bawean in the Java sea, Indonesia.
- Camera trap data revealed that the island is home to a population of 172 to 377 Bawean warty pigs.
- Given such a small population, the authors conclude that the Bawean warty pig should be listed as Endangered under the IUCN Red List.
For the first time ever, scientists have confirmed a population of fewer than 250 mature Bawean warty pigs on a small Indonesian island called Bawean.
This makes these pigs one of the world’s rarest pig species, according to a new study published in PLOS One.
Bawean warty pigs (Sus blouchi) are found only on the island of Bawean in the Java sea, Indonesia. Female Bawean warty pigs look a lot like wild boars (Sus scrofa). But the males have three pairs of large warts and golden yellowish hair fanning out from both sides of their head, researchers say.
Previously, most information about these pigs has been anecdotal. So to get an initial estimate of the number of Bawean warty pigs that roam the island, Mark Rademaker, a graduate student at VHL University of Applied Sciences in the Netherlands, and his colleagues, installed camera traps across 100 locations between November 2014 and January 2015.
The team did not have to wait long for footage of these elusive pigs.
“In the week we arrived on Bawean we decided to put up two camera traps in a field behind the village where one of the guides lived — we didn’t expect much, it was more to test the camera traps,” Rademaker told Mongabay. “But after a few chickens and a water buffalo, we got six videos of pigs!”
In the coming weeks, the installed camera traps continued to record videos of Bawean warty pigs on the island. Overall, the team estimated that the island is home to a population of 172 to 377 Bawean warty pigs. And this likely makes these pigs the rarest pigs in the world, according to the team.
Given such a small population, the authors conclude that the Bawean warty pig should be listed as Endangered under the IUCN Red List.
The pig’s population estimate is low, Rademaker said, but not unexpected.
“What you have to know is that Bawean is a small island with an area less than 200 square kilometers and there are quite some people as well, around 90,000,” he added. “The forest that’s left on Bawean is almost all in the five protected areas, which only totals around 46 square kilometers. That is not a lot of living space.”
Living on a small island with very little forest cover has meant that the pigs regularly come out of the forests at night and forage in the community forests and agricultural fields, looking for energy-rich food such as roots and tubers, the study found. This behavior is a bit worrying, researchers say.
This is because the pigs are likely to come into conflict with farmers around the area, Rademaker said, sometimes resulting in trapping and killing of the pigs in retaliation. Occasionally, hunters go into the protected areas with dogs to hunt down pigs, he added.
The team, however, found no evidence of wild boars on the island. And this is good news for the Bawean warty pigs, researchers say.
“If both species were present it would be likely they have interbred substantially, leaving us with very few or no genetically pure warty pigs,” Rademaker said.
- Rademaker M, Meijaard E, Semiadi G, Blokland S, Neilson EW, Rode-Margono EJ (2016) First Ecological Study of the Bawean Warty Pig (Sus blouchi), One of the Rarest Pigs on Earth. PLoS ONE 11(4): e0151732. doi:10.1371/journal.pone.0151732