BBC Wildlife Magazine, January 2003
Its fearsome-looking tusks are the most obviously unusual feature of the pig-deer of Sulawesi, but there’s plenty more to keep a babirusa researcher busy in the rainforest.
The smell of sulphur drifts across the still salt-lick. Perched high in a tree, I awkwardly shift position, small ants biting my skin. Pigeons drop from the trees to peck lazily at the mineral-rich soil, and the hot-upwelling spring in the centre of the lick bubbles. Otherwise, all is still.
Suddenly, framed against the jagged pandan leaves, a massive grey form appears and moves onto the open lick. Watching through binoculars, I zoom in on the grandeur of the tusks, curving elegantly over the animal’s forehead like a misplaced primeval headdress. He drinks quietly, feet sunk deep into the cool mud, body caked with layers of wet earth. His pungent smell wafts upwards on the hot afternoon air. This is who I’ve been perched here waiting for: the babirusa, inspiration of art and legend, endangered,elusive, unknown.
The babirusa is a rare, curly-tusked pig endemic to Sulawesi’s rainforests. Its most extraordinary features are its four amazing tusks, present only in the male: two upper tusks grow vertically through the snout and curve back around towards the forehead, while two others curve out from the lower jaw. These are what give the babirusa its name: babi means pig and rusa deer in the local language. The babirusa’s extraordinary appearance – the tusks, combined with a whiteish-grey, hairless, hippo-like body weighing up to 100kg – has always engendered interest, and it was mentioned in European literature as far back as 1650. Babirusas were kept as pets by early rulers in Sulawesi, and were reportedly given as gifts to visiting diplomats. The tusks were the inspiration for Balinese demonic masks.
Words: Lynn Clayton
Photo: Michel Gunther
“It is yet wonderfully rich in peculiar forms, in some cases absolutely unique upon the globe,” wrote Alfred Russel Wallace, the nineteenth-century naturalist, of Sulawesi’s wildlife.
And of all Sulawesi’s species, the babirusa is the most peculiar. Though classified as a member of the Suidae (pig) family, it is an aberrant pig on account of its tusks and more complex stomach. Today, it is in grave danger of extinction. With its rainforest habitat ravaged and illegal poaching for its meat, babirusa numbers are estimated at less than 10,000 individuals. Spread out over 100,000 hectares, it is an extremely difficult creature to find.
When I came to Sulawesi to search for a site to study the babirusa, I endured six months of fruitless surveys in the rainforest. Perched on tree platforms from dawn to dusk, I was rewarded at best by a fleeting glimpse of a babirusa’s tail passing by. I trekked into the forest with hunters, only to find their hunting grounds already bereft of babirusas. Finally, hunters guided me to Paguyaman, named for its massive river, and home of the forest-dwelling polahi people, who live at the feet of its jagged mountains. We travelled by longboat for two days, hauling the boat over rapids in the baking sun, till we got to Adudu – a name that means “Thank goodness we’ve finally arrived!”
Here, deep in the forest, we came upon a large natural salt-lick, 60m x 20m, devoid of vegetation, where babirusas gather to consume mineral-rich soil and water – a perfect observation site. The hunters built a tree tower of wood and palm leaves at the edge of the lick, and this is where I spent hundreds of hours over the next four years, piecing together a picture of the babirusa’s private life, the first such study of this species in the wild.
photo: Blake Dyer
Adult male babirusas, I discovered, usually come alone to the lick, while adult females visit in large groups including offspring of successive generations. They visit the lick throughout the day and occasionally at night; 5-6 pm is peak visiting hour. But what is it that brings them to the lick? Analysis shows that the soil and water lying there are rich in minerals, especially sodium. Babirusas may have a scarcity of this in their diet, which consists of fallen fruit, leaves and animal material, and so they visit the lick to fill the mineral gap. But other interesting possibilities come to mind. A key fruit in the babirusa’s diet is the coconut-sized pangi Pangium edule, which has a seed containing toxic
hydrocyanic acid. Babirusas consume the whole fruit, seed and all. Lick soil might help protect their digestive tract from these toxins, in the same way that leaf-eating monkeys negate the effects of toxic compounds in leaves by consuming soil. Alternatively, the high levels of calcium in the lick water (four times that of the nearby river water) might help in the formation of strong tusks. The salt-lick is certainly a meeting place for babirusas from all parts of the Paguyaman Forest, enabling them to maintain social contact with one another and males to locate oestrous females.
Sometimes, though, days would go by without a single sighting. I came to dread the moment that I’d see a long-awaited babirusa raise its nose into the air, catch my scent and flee with its group back into the vegetation. Occasionally, though, the rewards werespectacular. Nothing beats the sight of 30 or 40 babirusas congregating at dusk. These gatherings are marked by intense interactions and an unforgettable cacophany of vocalisations. The highlight of the gatherings is combat between adult males, which sees two huge animals rear up on their hind legs, facing each other, heads high, in an extraordinary symmetrical ‘dance’. The tusks aren’t used, and a high-pitched shrieking accompanies the dance, which lasts for just a few minutes. In more aggressive encounters, one combatant may be lifted up off the ground by the head of the other(who remains on the ground), and impaled on his sharp lower tusk. Such impaling leads to severe wounds on the animal’s neck. This style of combat is rare in suids, and is recorded in only one other species, Sus scrofa cristatus.
Babirusa frequently wallow at smooth-sided, multi-chambered mud wallows hollowed out by the animals themselves. Mud-wallowing not only aids heat relief: wet mud may also increase the slipperiness of the skin, making it more difficult for an opponent to get a grip on the body. Mud rubbed by babirusa onto trees around wallows may help to impregnate the animal’s odour throughout its range, while resinous exudates from rubbing trees provide a protective layer against tusk injury and shoulder pushing.
Aggressive encounters are frequently followed by courtship sequences, in which the male circles around the lick after an oestrous female, emitting a metronome-like lip-smacking; mating takes place in the cover of the forest.
The function of the babirusa’s extraordinary tusks has been the subject of speculation for centuries. Local legend has it that the animal uses them to hang from branches, in order to spy out females passing below. Another suggestion is that they might protect the babirusa’s eyes from thorn damage while foraging. As only male babirusas have tusks, it is most likely that, like a deer’s antlers, they signal a male’s prowess and fighting ability. Some say the ultimate purpose of babirusa fighting is to break off the upper tusk of another male, rendering him less attractive to females. Certainly, many old male babirusas can be seen with at least one or both upper tusks broken off and only stumps remaining. Only the long, sharp, lower tusks are used as weapons, against both other babirusas and domestic dogs.
The babirusa is gravely threatened from illegal poaching for its meat, in spite of legal protection under Indonesian wildlife law. Patterns of babirusa trade reflect local religious differences: the Christian area of Minahasa (at the tip of North Sulawesi) is the marketplace for wild meat from all over Sulawesi. Around 30 dealers leave Minahasa each week in small pick-up trucks to purchase wild meat 600km west, where the dominant religion is Islam and such meat is not consumed. Babirusas and Sulawesi wild pigs Sus celebensis, which are not legally protected, are trapped in string leg snares set by poachers under fruiting trees or along regularly-used pig paths in the forest.
The babirusa is particularly vulnerable to hunting as it has a slow reproductive rate, producing only one or two piglets each year. Smoked or fresh, the meat is loaded onto trucks at collection points and transported back to Minahasa, usually in the small hours of the morning, when patrols are less vigilant. Babirusa meat is sold openly in the public market, alongside the meat of bats, monkeys, snakes, rats, Sulawesi wild pigs and dogs, and it fetches about £1.50 a kilo. In 1988, 17 babirusas and two anoas (endemic dwarf buffaloes) were confiscated by a government team at Paguyaman, the result of one week’s catch around the Adudu salt-lick.
Babirusa and Anoa meat
In 1997, the Paguyaman Forest was legally protected as a 31,000 hectare nature reserve called Suaka Margasatwa Nantu. This area is of vital importance, not only for the babirusa but also for the anoa, the tiny, giant-eyed spectral tarsier and the locally endemic Heck’s macaque. Reserve status protects the pristine rainforest and its wildlife from logging, poaching and slash-and-burn clearance. The status was won after an eight-year struggle.
Teams of forestry department officials, police, researchers and hunters-turned-conservationists patrolled the forest by longboat and on foot, detaining illegal consignments of timber and removing poachers’ snares. By night, they waited for meat dealers’ vehicles to enter nearby villages and load their illegal cargo of babirusa meat; at dawn, they came upon raft after raft of massive illegal timber blocks being poled down river. Pioneering law enforcement was key to the progress. The first- ever prosecution for illegal babirusa trading was processed and this has clearly acted as a deterrent to others: the number of babirusas sold in the local market at Langowan has fallen from 30 a week in 1997 to five a week in 2002.
The approval for the nature reserve came not a moment too soon. Outside its perimeter fences, the destruction of forest proceeded apace. Night and day, overloaded logging trucks ground up the steep forested slopes across the river. Huge, buttress-rooted trees on the floodplain were burned, as 60km of logging road were carved into the area, and the Paguyaman river was bridged with massive trees felled from its forests. We often observed confused babirusas searching for lost wallows and pangi trees, and each day saw babirusa skulls lying in the clear streams – remains of the logging team’s meal the previous evening.
But within the reserve, a different story is unfolding. Supported by the Darwin Initiative for the Survival of Species programme and the Foreign and Commonwealth Office’s Environment Fund, the local community is getting involved in establishing Paguyaman as a functioning nature reserve. For example, a three-day workshop in July 2002 drew together 30 people from settlements all around the reserve to discuss its future protection. Development of the local economy was a key issue, and buffer-zone tree-planting programmes have begun with the aim of reducing dependence on the forest. In the months following, we met workshop participants around the reserve edge, telling others of the importance of Paguyaman and becoming active in reserve protection efforts.
Today, the district government is proposing to upgrade the reserve to a 100,000ha national park, and an NGO, Yayasan Adudu-Nantu International (YANI), has been established to carry forward the vision.
Meanwhile, back at the salt-lick, there’s a rustling high up in the tree hide: a local childpeers excitedly through the hide’s window at 10 babirusas gathered on the lick below. A macaque swings in the trees nearby. There is hope.
Babirusa business
- Within the Suidae (pig) family, the babirusa Babyrousa babyrussa is classified as the sole member of the sub-family, the Babyrousinae.
- The babirusa’s elaborate upper tusks are the upper canine teeth, whose sockets are reversed, so they grow vertically up through the skin of the snout. Tusks are only present in male babirusas and emerge at sexual maturity; they are initially slender and tiny, increasing in size with age.
- The babirusa is confined to the islands of Sulawesi and its smaller neighbours, Buru and Sula. Three subspecies are recognised, differing in size, hair covering and skull and teeth characteristics. Adult males of the mainland Sulawesi subspecies weigh up to 100kg; females there weigh up to 60kg.
- Unlike other pigs, babirusa males will fight standing on their hind legs in a ‘boxing’ pose.
- The babirusa’s stomach has a series of compartments, making it more complex than that of any other pig. This indicates that it can digest leaves and shoots by using microbial fermentation, like cattle — though the babirusa doesn’t chew the cud.
