December 15, 2017

On the Indonesian island of Sumatra, already home to the Sumatran orangutan, a new species of the great orange ape has recently been named: the Tapanuli orangutan (Pongo tapanuliensis). Orangutans are shy and reclusive, and they live in remote jungle areas. This, combined with their small numbers, can make the animals extremely hard to find. It is little wonder, then, that every once in a while people should learn of a new species. Since 2001, the Tapanuli is the third newly recognized species of orangutan, following its recently named Sumatran cousins (Pongo abelii) and the Bornean orangutan (Pongo pygmaeus). An international team of anthropologists and evolutionary biologists recently described the Tapanuli species in the journal Current Biology. Among all the great apes, the Tapanuli orangutan’s population is the smallest. The team estimated Tapanuli numbers at just 800.

A Tapanuli orangutan relaxes in the comfort of a tree on the island of Sumatra. Credit: Tim Laman (licensed under CC BY 4.0)

In the 1930’s, scientists reported an orangutan population in the rain forest of Batang Toru on Sumatra. However, it was not until 1997 that scientists rediscovered the population and later began studying the animals. Michael Krützen, a Swiss evolutionary geneticist from the University of Zurich, is one of the authors of the Current Biology report. Krützen believes the new orangutan species differs genetically, physically, and behaviorally from both the Sumatran and Bornean species. The three species also seem to have distinct evolutionary lineages. Tapanuli orangutans are believed to be direct descendants of the first orangutans that arrived in Sumatra from mainland Asia long ago.

Tapanuli orangutans are found only in the isolated high-elevation rain forest of Batang Toru. Their small population is distributed over about 386 square miles (1,000 square kilometers), an area roughly the size of Dallas, Texas. Calls made by Tapanuli males vary from calls made by Sumatran and Bornean males. Sumatran males produce calls that are long and low-pitched, while those on Borneo belt out shorter and higher-pitched calls. The calls of Tapanuli males fall somewhere in between.

Tapanuli orangutans have slightly different facial features (including a noticeable mustache) from other orangutans, as well as smaller skulls. Female Tapanuli orangutans have beards, unlike Bornean orangutans. Tapanuli fur is slightly different, too: frizzier and more cinnamon-colored. The analysis of Tapanuli bones, plus a genetic review of blood samples, convinced the anthropologists and biologists that they had found a unique orangutan species.

Jungle cats hunt Tapanuli orangutans, but otherwise the apes have few natural predators. Human activity poses the biggest threat. The spread of agriculture, particularly palm oil plantations, has greatly reduced the orangutan’s habitat. Plans for a gold mine and a hydroelectric plant in the area also pose threats to the animal’s Batang Toru forest. With only about 800 Tapanuli orangutans living in the wild, urgent study and conservation is needed to help protect the endangered orange apes from extinction.

April 5, 2017

Scientists, never satisfied with the current number of known frogs in the world, have added two new species of toads to the ever-growing list. These new toads, native to Indonesia, have DNA so different from other toads that scientists went a step further and gave them their own genus, Sigalegalephrynus. When classifying living things, a genus (a group of related animals or plants) ranks below a family or subfamily and above a species. The discovery of a new frog genus is rare. The last one in Asia occurred in the 1800’s. The new toads live in a densely vegetated volcanic region of Batang Gadis National Park on Sumatra, one of the world’s largest islands. One species was found in a shallow cave; the other was scurrying about the nearby forests. (Remember that frogs and toads are not different animals. Toads are simply certain types of frogs.)

A toad of the new genus Sigalegalephrynus sits among the bristly hairs of a leaf. These toads resemble puppets used in funerary festivals in Sumatra, the island in western Indonesia where the toads live. Credit: © Eric N. Smith, Amphibian And Reptile Diversity Research Center/University of Texas at Arlington

Researchers spent eight months in 2013 and early 2014 taking inventory of the toads in the Sumatra Highlands. Then, for more than a year, they studied their findings and analyzed the physical and genetic characteristics of these unusual specimens. The researchers used nuclear and mitochondrial cell data to describe the toads, and the results showed that members of Sigalegalephrynus are unique among other toads of that region. The researchers’ findings were published in the March 2017 issue of the journal Herpetologica. Herpetology is the branch of zoology concerned with the study of reptiles and amphibians.

The new toads have unusual chattering mating calls unlike other frogs of their native land. Sigalegalephrynus are medium-sized toads with lanky limbs. Most are mottled dark brown and tan, but one version has green colors on its body. Because of their resemblance to wooden puppets used in local ceremonies in the region, these frogs earned the name of “puppet toads.” But their name can extend further. The wooden puppets are used during specific funerary festivals to appease the spirits of the dead. So, these newfound amphibians are sometimes called “puppet toads of the dead.”

The discovery of these puppet toads comes as scientists and conservationists feel mounting urgency to locate and classify species throughout Indonesia, where toads and many other forms of life are threatened by deforestation. About half of Indonesia’s amphibian species are not found anywhere else in the world. The future of the “puppet toads of the dead” and other Indonesian wildlife depends on saving the precious forests they call home.

April 11, 2012

Indonesia’s Aceh province was shaken this morning by two major earthquakes–one with a magnitude of 8.6, the other measuring 8.3. The earthquakes were centered below the Indian Ocean at a depth of 20 miles (33 kilometers), some 300 miles (495 kilometers) off the coast of Banda Aceh, the provincial capital. Fearing a tsunami like the disastrous one in 2004, the Pacific Tsunami Warning Center issued a tsunami warning. The warning was cancelled after no massive waves developed from the quake. The Indian Ocean tsunami of 2004 killed some 250,000 people in coastal areas of Southeast Asia, South Asia, and East Africa.

An earthquake under the ocean may cause a tsunami, a series of ocean waves that can cause tremendous destruction along coastlines. (World Book illustration by Matt Carrington)

Indonesia is regularly struck by earthquakes. The country’s island of Sumatra is close to an active subduction zone, where the Indian-Australian tectonic plate presses into and under the Eurasian plate. The collision of the plates has created a huge depression on the ocean floor known as the Sunda Trench. Strain between the plates at this depression is eventually released in the form of an earthquake.

Additional World Book articles

• Big Waves: Tracking Deadly Tsunamis (a special report)
• When the Earth Moves (a special report)
• Indonesia 2004 (Back in Time article)
• Indonesia 2005 (Back in Time article)