On these remote Indonesian islands lives a wild pig whose upper canines grow upwards, pierce its snout, and can lethally curve back into its own brain.
A problem of dental engineering
The Togian babirusa (Babyrousa togeanensis) is a member of the pig family found only on the Togian Islands of Indonesia. A bizarre feature of the male babirusa is its two pairs of tusks. Like other pigs, its lower canine teeth grow upwards and outwards. Uniquely, however, the male's upper canines grow continuously throughout its life, erupting vertically through the flesh and bone of the snout. This happens because the tooth sockets for the upper canines are rotated 180 degrees. These ever-growing tusks, which can reach lengths of 30 centimeters, then curve backward toward the forehead.
This dental arrangement presents a serious problem. If a male babirusa does not naturally wear down its tusks through activity, they can continue their backward curve until they pierce the skull and penetrate the brain, causing a fatal injury. This phenomenon, though rare, has been documented. Female babirusas do not share this trait; their upper canines are either very small or absent entirely.
The function of the tusks
The exact purpose of these strange upper tusks is a subject of scientific debate. Early theories suggested they were used for fighting, but the tusks are brittle and not well-suited for combat. Observations of male babirusas competing for mates show they do not lock these upper tusks. They often rear up on their hind legs and "box" each other with their front hooves. The more dagger-like lower tusks are used for slashing.
One prevailing hypothesis is that the upper tusks serve a defensive purpose, acting as a shield to protect the face and eyes from an opponent's sharp lower tusks during fights. Another theory proposes that the tusks are a form of sexual selection, similar to a peacock's tail. In this view, large, well-formed tusks signal genetic fitness to potential mates, even though they pose a potential long-term danger to their owner. The danger of self-impalement only occurs later in life, typically after the male has had opportunities to reproduce and pass on its genes.
The Togian babirusa is listed as an endangered species, with a small and fragmented population estimated at fewer than 1,000 individuals. The primary threats are habitat loss from logging and agriculture, and hunting by local farmers who view them as pests.
💡Fun Facts
The name "babirusa" comes from the Malay words for "pig" (babi) and "deer" (rusa), a reference to its deer-like legs and antler-esque tusks.
Unlike most other pigs, babirusas do not root for food with their snouts, possibly due to the lack of a special rostral bone in the tip of the nose.
A 2022 camera-trap study estimated the total adult population of Togian babirusas to be around 440 individuals.
The Togian babirusa was officially recognized as a distinct species, separate from other babirusas, in 2002.
The Togian Islands National Park is accessible year-round, but the babirusa are wild animals and sightings are not guaranteed. They are most active in the early morning and late afternoon.
Admission
Foreign tourists pay an entrance fee of Rp 150,000 (about $10 USD) to the national park.
Accessibility
The islands are remote and require significant travel. Getting around involves local ferries and chartered boats, and viewing wildlife requires trekking through dense rainforest.