- The Bornean banteng is considered to be a subspecies of the banteng found on Java, but some scientists are arguing the animal should be recognized as its own species.
- Local indigenous communities are trying to protect the banteng, invoking customary law to fine their own members and outsiders who hunt it. Community planning has spaced rice fields farther apart so that the banteng have room to travel.
- In the headwaters region of the Belantikan River in central Borneo, only 20 or 30 Bornean banteng are known to remain.
LAMANDAU, Indonesia — At the headwaters of the Belantikan River on the island of Borneo, an organization committed to protecting orangutans is extending its efforts to a slightly less charismatic megafauna: the endangered Bornean banteng, a type of wild cattle.
Long thought to be subspecies of the banteng found on Java, Bos javanicus, a growing body of DNA evidence suggests the Bornean banteng may be its own species — a distinction conservationists hope will earn the animals the attention they need to help ensure their survival.
“We’ve been researching them since 2003,” said Eddy Santoso, the director of the Indonesian Orangutan Foundation, known by its local acronym of Yayorin. A master’s degree student initially caught wind of the elusive population in 2003, through stories from the local community, but it wasn’t until 2007 that the first tracks were confirmed. Eventually researchers found droppings and horn marks deep in the forest.
Motion-activated cameras placed near mineral salt licks in 2013 captured the first photographic proof that the small population indeed exists. Ultimately, a network of 32 video cameras placed throughout the 64-square-kilometer (25-square-mile) study area recorded the banteng. Several were traveling in family groups, with calves up to 3 years old following their mothers through the thick forest. The best estimates put the total number of wild cattle living in the Belantikan area at no more than 20 animals.
Scientists estimate somewhere between 5,000 to 8,000 Bos javanicus remain in the wild, but habitat loss, hunting, and crossbreeding with domestic cattle have placed the species on the IUCN’s Red List as endangered.
Three distinct subspecies are currently recognized: B. j. javanicus occupy the Indonesian islands of Java and Bali, while B. j. birmanicus are found throughout mainland Southeast Asia. The Belantikan population of banteng, along with a few other isolated groups found on the island of Borneo, have long been considered a third subspecies, B. j. lowi, but physiological differences, and now genetic markers, suggest they may be their own species entirely.
“Because accurate baseline data about the banteng is lacking in Indonesia, it has long been assumed that these animals are descendants of the Javan banteng,” said Iman Safari, program manager at Yayorin.
But according to Iman, recent genetic tests conducted by researchers at the Bogor Institute of Agriculture indicate that the Bornean banteng may actually be more closely related to the gaur (Bos gaurus) than B. javanicus. Ranging from India to mainland Southeast Asia, the gaur is the world’s largest wild bovine.
The genetic analysis of a protein known as Cytochrome C oxidase I found a 4.3 percent difference between the Bornean banteng and the Javan banteng. Analysis on a different protein, Cytochrome B, put the species separation at 5.5 percent.
New species have been declared based on a genetic difference of only 3 percent, Iman said, so the findings support the notion that the Bornean banteng may actually be a separate species.
“What this means, anyway,” Iman said, “is that it has given us the confidence to push to declare this group a new species.”
He pointed to the 2017 declaration of the Tapanuli orangutan (Pongo tapanuliensis) as a separate species from the Sumatran orangutan (Pongo abelii) as a precedent. This, Iman said, could serve as a roadmap for how the Yayorin researchers can go about getting their banteng recognized. He said he hoped to speed through the typically long and laborious process of declaring a new species.
If the Bornean banteng is indeed a separate species, it would likely be listed as critically endangered, given the small remaining population size and rapidly shrinking habitat. This distinction could help bring new attention and resources to help protect the animals, who share the forest with Yayorin’s main species of concern: the Bornean orangutan (Pongo pygmaeus).
“Orangutans are an umbrella species that exist as part of a greater ecosystem,” Eddy said, “and if there are banteng in the orangutan’s ecosystem, we will work to protect the banteng as well.”
In the early 2000s, the Belantikan forest was home to some 6,000 orangutans — the largest wild population found outside of a national park, wildlife reserve or other protected forest. Around the same time, only about 30 banteng were thought to exist in the same area. A census conducted two years ago now puts the number of banteng closer to 20.
The Belantikan River runs along the Schwaner Mountains, a natural barrier between Indonesia’s Central and West Kalimantan provinces. Yayorin’s center of operations is in Lamandau district, near Nanga Matu, the furthest upstream village. Nanga Matu, like most villages around the headwaters, is surrounded by an area classified by the government as production forest, which means it’s open to logging and other commercial activity.
But the lands around the village are in better shape than in many other parts of the district that have been converted to oil palm plantations. The Belantikan forest still contains trees with trunks more a meter (3 feet) in diameter, and support some 56 species of plants known to be eaten by the banteng.
This isn’t to suggest that the forest around Nanga Matu is pristine. On the contrary, a logging company previously held a concession covering some 980 square kilometers (380 square miles) in the district, although Eddy said the total area had since decreased. Yet despite this disturbance, monitoring by Yayorin has confirmed that a small population of banteng has been able to sustain itself up to this point, and conservation efforts are expected to protect their future.
According to Iman, 17 square kilometers (7 square miles) of the headwaters area have been designated as conservation forest by the Lamandau government, and he is encouraged by the efforts of several villages in the region that have issued bylaws to protect the banteng. Some communities have invoked customary law to fine their own members and outsiders who hunt the banteng, and community planning has spaced rice fields farther apart so that the banteng have room to travel.
“In the past the fields were planted too close together,” Iman said, “and if a banteng trampled a field, damaging the harvest, the villagers would automatically kill it.”
Nanga Matu village is also considering developing a conservation tourism package, though they admit it won’t likely be of mass appeal, and will probably be quite expensive.
Other proposals for helping to protect the species include a sanctuary breeding program, but Iman is concerned that this will be difficult, as banteng are easily stressed; calves separated from their mothers don’t often survive.
These ideas are being discussed for possible implementation by the newly established Forum for Conservation of Belantikan Banteng, which will work with the local government and communities to develop a conservation plan that meets the needs of all parties.
“If nothing else, we hope to increase awareness of the banteng,” Iman said, “and maybe get its status raised.” He points out that orangutans, he pointed out, are classified as critically endangered, despite there being far more of them than the banteng — which is only listed as endangered.
A previous version of this article mistakenly said that only 20 to 30 Bornean banteng remain alive in the wild. That is actually the number that exist in the Belantikan River headwaters region. There are Bornean banteng found in Sabah, for example.
Banner: A group of Bornean banteng. Image courtesy of Yayorin.
This story was reported in part by Mongabay’s Indonesia team and was first published on our Indonesian site on Mar. 10, 2019.
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