New study investigates the role of Tambora eruption in the 1816 'year without a summer'

By: Thomas Schmitt Attorney on September 17, 2019 / comment : 0 Climate Change, Earth Science, Geology, Indonesia, Palaeontology

A new study has estimated for the first time how the eruption of Mount Tambora changed the probability of the cold and wet European 'year without a summer' of 1816.

Mount Tambora in Indonesia erupts [Credit: Ron Wood from the cover of 'The Year Without Summer']

It found that the observed cold conditions were almost impossible without the eruption, and the wet conditions would have been less likely.

1816 recorded exceptionally low global temperatures, with central and Western Europe seeing a particularly cold and wet summer that led to widespread agricultural failures and famines.

The 1815 eruption of Mount Tambora in Indonesia has long been assumed to have been the cause, with a link made as early as 1913. Now, using historical data and modern modelling techniques, researchers led by the University of Edinburgh, UK, have estimated just how important the eruption was.

The study's lead author, Dr Andrew Schurer, from the University of Edinburgh, said: "The eruption of Mount Tambora in April 1815 was among the most explosive of the last millennium. It had an enormous impact locally, devastating the island of Sumbawa. The eruption injected a huge amount of sulphur dioxide (SO2) into the stratosphere, which would have quickly spread across the world, oxidising to form sulphate aerosols.

"These volcanic aerosols reduce net shortwave radiation causing widespread, long lasting surface cooling. They also lead to a reduction in global rainfall, while wettening some dry regions, and causing dynamic changes in the large-scale circulation of both ocean and atmosphere."

The research team used early instrumental data, combined with new climate simulations from two different models, to conduct an event attribution analysis. Their aim was to determine if, and by how much, the volcanic forcing affected the probability of cold and wet conditions in this 'year without a summer'.

Their results, from summers with similar sea-level-pressure patterns to 1816, using both observations and unperturbed climate model simulations, show that the circulation state can reproduce the precipitation anomaly without external forcing, but only explains about a quarter of the anomalously cold conditions.

Dr Schurer said: "Including volcanic forcing in climate models can account for the cooling, and we estimate it increases the likelihood of the extremely cold temperatures by up to 100 times.

"Although the observed sea-level pressure pattern can account for much of the observed anomalously wet conditions, even without volcanic forcing, there is strong evidence in the model simulations that the volcanic eruption increases the chance of such a wet summer over Central Europe, by about 1.5 to three times.

"Mount Tambora played a dominant role in causing the observed cold conditions, and probably also contributed to the anomalously wet conditions. Without volcanic forcing, it is less likely to have been as wet and highly unlikely to have been as cold."

The findings are published in Environmental Research Letters.

Source: Institute of Physics [September 17, 2019]

Holy Pleistocene Batman, the answer's in the cave

By: Thomas Schmitt Attorney on April 25, 2019 / comment : 0 Biodiversity, Earth Science, Indonesia, Palaeoclimate, Palaeontology

Let's say you wanted to solve a 20,000-year-old mystery, where would you start? Perhaps archaeology and geology come to mind. Or, you could sift through a 3-metre pile of bat faeces.

Bats flying out of an Indonesian cave for their nightly meal [Credit: Chris Wurster]

Researchers from James Cook University in Cairns, Australia, chose the bat poo in their quest to answer to a long-standing question: why is there some much biodiversity on the islands of Sumatra, Borneo and Java, when not so long ago (geologically speaking) they were all part of one vast continent?

One theory has been that the former continent (Sundaland) was dissected by a savanna corridor. "That might explain why Sumatra and Borneo each have their own species of orang-utan, even though they were linked by land for millions of years," Dr Chris Wurster said. "The corridor would have divided the two separate rainforest refuges, as the sea does now."

The corridor theory has been boosted by millions of insect-eating bats, which have gathered evidence about the landscape over millennia and deposited it in layers in their caves.

"Bat poo is highly informative, and especially so in the tropics, where the climate can make some of the more traditional modes of investigation less available," Dr Wurster said.

A three-metre pile of bat faeces at Salah Cave in Borneo gave the researchers a 40,000-year-old record composed of insect skeletons.

"We can't tell what insects the bats were eating throughout that time, because they're in tiny fragments, but we can read the chemistry," Dr Wurster said.

Bats clustering together on the wall of an Indonesian cave [Credit: Chris Wurster]

"Eating insects that have been feeding on tropical grasses results in faeces with a characteristic chemical imprint. It's quite different from the result you'd get from eating insects that fed on tropical trees."

According to the bat record the landscape around Saleh Cave (now featuring lush rainforest) was once dominated by tropical grasses.

"Combined with other cave studies in the region, this leads us to support the corridor theory, and also gives us some confidence as to the extent of the corridor," Dr Wurster said.

The corridor could also shed light on human pre-history.

"A savanna corridor, which would be much more easily traversed than rainforest, might help to explain how people moved relatively quickly through this region and on to Australia and New Guinea."

'Savanna in equatorial Borneo during the late Pleistocene' is published in the latest edition of Scientific Reports.

Dr Chris Wurster is a Senior Research Associate at James Cook University, specialising in stable isotope geochemistry.

Source: James Cook University [April 25, 2019]

Tropical forest the size of England destroyed in 2018: report

By: Thomas Schmitt Attorney on April 25, 2019 / comment : 0 Biodiversity, Brazil, Ecosystems, Environment, Indonesia, Natural Heritage, Rainforests

Last year humanity destroyed an expanse of tropical forest nearly the size of England, the fourth largest decline since global satellite data become available in 2001, researchers reported Thursday.

Indonesia's President Joko Widodo inspects a peatland clearing that was engulfed by fire in 2015 [Credit: Romeo Gacad/AFP]

The pace of the loss is staggering -- the equivalent of 30 football fields disappearing every minute of every day in 2018, or a total of 120,000 square kilometres (46,000 square miles).

Almost a third of that area, some 36,000 km2, was pristine primary rainforest, according to the annual assessment from scientists at Global Forest Watch, based at the University of Maryland.

"For the first time, we can distinguish tree cover loss within undisturbed natural rainforests, which contain trees that can be hundreds, even thousands, of years old," team manager Mikaela Weisse told AFP.

Rainforests are the planet's richest repository of wildlife and a critical sponge for soaking up planet-heating CO2.

Despite a slew of counter-measures at both the national and international level, deforestation has continued largely unabated since the beginning of the century.

Global forest loss peaked in 2016, fuelled in part by El Nino weather conditions and uncontrolled fires in Brazil and Indonesia.

The main drivers are the livestock industry and large-scale commodity agriculture -- palm oil in Asia and Africa, soy beans and biofuel crops in South America.

Small-scale commercial farming -- of cocoa, for example -- can also lead to the clearing of forests.

Logs in the forest in Xapuri, Acre State, in northwestern Brazil [Credit: Yasuyoshi Chiba/AFP]

A quarter of tropical tree cover loss in 2018 occurred in Brazil, with the Democratic Republic of Congo and Indonesia each accounting for about 10 percent.

Malaysia and Madagascar also saw high levels of deforestation last year.

Nearly a third of primary forest destruction took place in Brazil (13,500 km2), with the Democratic Republic of Congo (4,800 km2), Indonesia (3,400 km2), Colombia (1,800 km2) and Bolivia (1,500 km2) rounding out the top five.

Madagascar lost two percent of its entire rainforest in 2018.

"The world's forests are now in the emergency room," said Frances Seymour, a distinguished senior fellow at the World Resources Institute, an environmental policy think tank based in Washington DC.

"The health of the planet is at stake, and band aid responses are not enough," she added.

"With every hectare lost, we are that much closer to the scary scenario of runaway climate change."

Globally, forests absorb about 30 percent of manmade greenhouse gas emissions, just over 11 billion tonnes of C02 a year.

Oceans are also a major "sink", soaking up another 23 percent.

Progression of deforestation in the Brazilian Amazon, with total area by state [Credit: Maria Scarpinelli/AFP]

Burning or clear-cutting vast tracts of tropical forest not only releases carbon into the atmosphere, it reduces the size of the sponge that can absorb CO2.

One bright spot in the report was Indonesia, which lost 3,400 km2 of primary forest in 2018 -- a 63 percent drop compared to 2016.

In 2015, massive forest fires on Sumatra, Borneo and other Indonesian islands levelled 20,000 km2 and generated health-wrecking pollution over a large swathe of Southeast Asia.

In Brazil, however, trend lines are moving in the wrong direction.

"Our data shows a big spike in forest loss in 2016 and 2017 related to manmade fires," Weisse said of Brazil.

"Shockingly, we are also seeing invasions into indigenous lands that have been immune to deforestation for years."

Brazil's President Jair Bolsonaro, who come into office in January, has vowed to curtail environmental regulations and allow commercial farming and mining on indigenous reserves, which comprise more than 10 percent of Brazil's territory.

The researchers emphasised that Bolsonaro has not been in office long enough to assess the impacts of his policies on deforestation.

In West Africa, meanwhile, 70 percent of primary forest loss in Ghana and Ivory Coast occurred in protected areas, pointing up the need for stricter enforcement.

Author: Marlowe Hood | Source: AFP [April 25, 2019]

New study claims large 10,000-year-old pyramid-like structure lies under Mount Padang in West Java

By: Thomas Schmitt Attorney on December 20, 2018 / comment : 0 Archaeology, Asia, Indonesia, Java, South East Asia

A new study claims that underneath a mountain in Indonesia lies the world’s oldest pyramid. The site, Gunung (Mount) Padang, is a hill with abundant archaeological evidence. But the new study claims that the hill is in fact a layered series of ancient structures dating over 10,000 years back.

An aerial photograph of Gunung Padang, Indonesia [Credit: Danny Hilman Natawidjaja]

The study was carried out over several years and researchers claim that the structure is not superficial, but rooted into greater depth covering an area of at least 15 hectares. With the use of ground penetration radar, seismic tomography and archaeological excavations combined, the team of researchers say that many layers hide beneath the hill constructed in several prehistoric periods.

The top layer, a megalithic structure comprising rock columns, walls, paths and spaces is constructed on a second layer about 1-3 metres deep below the surface. The second layer comprises an arrangement of rocks organised in a matrix structure. A third layer, 15 metres below the surface, also comprises arranged rocks, as well as chambers. The rocks are basalt and have been carved by humans.

3D aerial photography of Gunung Padang pyramid and interpretations of its subsurface structures [Credit: Danny Hilman Natawidjaja/SAGU Fall Meeting]

Radiocarbon dating has indicated that the first layer could be about 3,500 years old, the second about 8,000 years old and the third one dates to the period of 9,500-28,000 years back.

Although there is no concrete evidence on the use of these structures, researchers believe that the ancient pyramid could have served a religious purpose.

At least three layers are claimed to have been identified by the research team with the use of various techniques [Credit: Danny Hilman Natawidjaja]

Geophysicist Danny Hilman Natawidjaja, from the Indonesian Institute of Sciences and leader of the team, highlights the importance of the structure since it proves that prehistoric societies were not as primitive as it is widely believed.

The study has not been received with the same enthusiasm by the entire scientific community, though. Many researchers are not convinced as to the results and challenge the team’s methods and findings.

The findings were presented at the annual meeting of the American Geophysical Union in Washington, DC last week.

Source: Archaeology and Arts [December 20, 2018]

Study casts new light cast on fishing throughout history

By: Thomas Schmitt Attorney on November 12, 2018 / comment : 0 Archaeology, Asia, Indonesia, South East Asia

A new study from The Australian National University (ANU) has revealed new insights into ancient fishing throughout history, including what type of fish people were regularly eating as part of their diet.

Credit: ANU

The study looked at fish bones unearthed in an archaeological dig on the Indonesian island of Alor -- home to the world's oldest fish-hooks ever found in a human burial site, dating back to about 12,000 years.

Lead archaeologist Dr Sofia Samper Carro of the ANU School of Archaeology and Anthropology said on the study identified a shift in fishing behaviours about 7,000 years ago.

"People on Alor people were fishing for open water species about 20,000 years ago, then about 7,000 years ago they started to fish exclusively for reef dwelling species," she said.

Dr Samper Carro said a similar pattern was identified on the nearby island of Timor, indicating that the change in behaviour was due to environmental circumstances.

The dig site at Alor Island [Credit: ANU]

"It seems to be due to changes in sea levels and environmental conditions, although human-induced changes cannot be ruled out," she said.

The results were made possible through the use of an analysis method traditionally used in biology to identify fish habitat in archaeological material. Dr Samper Carro said she was forced to experiment with a new approach due to the difficulty in determining the difference between the very similar looking bones of the area's 2,000 known species of fish.

"This study is the first time researchers have been able to reliably determine fish habitat using vertebra through this method, and represents a significant step forward in being able to track human behaviour throughout history," Dr Samper Carro said.

One fish vertebrae looks much like another [Credit: ANU]

"Most of the bones you find in archaeological sites are vertebra, which are very complicated to identify to species and all look very similar. If we don't know the species, we don't know their habitat. In Indonesia you have more than 2,000 species of fish, so to be able to know which bones belong to which species you would need 2,000 species of fish in your comparative collection."

"I spent probably five months trying to match each fish vertebra to a species and I think I got through 100 out of 9,000 bones, so I needed to find another method."

Dr Samper Carro instead turned to geometric morphometrics, a process that looks at slight differences in size and shape of physical objects. Using more than 20,000 digital images and plotting 31 points on each bone, she was able to digitally identify the likely habitat from each vertebra.

The study is published in the Journal of Archaeological Science.

Source: Australian National University [November 12, 2018]

The secret behind coral reef diversity? Time, lots of time

By: Thomas Schmitt Attorney on November 09, 2018 / comment : 0 Biodiversity, Ecosystems, Indonesia, Natural Heritage, Oceans, Papua New Guinea, Philippines, Wildlife

Strap on a diving mask and fins and slip under the crystal-clear water near a coral reef in Indonesia, Papua-New Guinea or the Philippines, and you'll immediately see why divers and snorkelers from across the world flock to the area. Known as the Coral Triangle, the region is famous for its unmatched diversity of reef fish and other marine creatures.

Until now, researchers had a hard time explaining why the Coral Triangle in the Central-Indo Pacific  is the world's leading spot of marine biodiversity [Credit: GreensMPs/Flickr]

Fish of all shapes and colors dart in and out of crevices created by the dazzling shapes of corals, colorful sponges and other reef-building organisms. With a little luck, a diver might catch a glimpse of a shark patrolling the reef or a turtle soaring across the landscape of colors.

While underwater enthusiasts have long known and cherished the biodiversity in the Central-Indo Pacific Ocean, scientists have struggled for more than half a century to explain what exactly makes the region the world's No. 1 hot spot of marine biodiversity and sets it apart from other marine regions around the world.

Several hypotheses have been put forth to explain the Central-Indo Pacific region's extraordinary diversity. Some researchers suggested species emerge at a faster rate there compared to other parts of the world's oceans, while others attributed it to the region's central location between several species-rich swaths of ocean in the broader Indo-West Pacific. Still others pointed to the region's low extinction rates.

Now, a study led by University of Arizona doctoral student Elizabeth Miller has revealed that Indo-Pacific coral reefs have accumulated their unrivaled richness of fish species not because of some unknown, elusive quality, but simply because they had the time.

"People used to think that new species evolve more quickly in tropical marine areas, so you get the high diversity we see today very quickly," Miller said. "Instead, we found that diversity in the Central-Indo Pacific has slowly built over a long time."

The study, published in the journal Proceedings of the Royal Society of London, is the first to show a direct link between time and species richness, according to Miller.

Until now, Miller explained, it was widely believed that tropical coral reefs, similar to tropical rain forests, are hot spots of biodiversity because of an intrinsic propensity to diversify into more species than other regions. Her research showed that wasn't the case.

A clownfish seeks shelter in its sea anemone home in the Great Barrier Reef, which is part of this study  [Credit: Deborah Shelton]

The team discovered that speciation rates are actually higher in cold marine areas such as the Arctic and Antarctic. However, while changes in biodiversity in the Central-Indo Pacific region could be compared to a slow but long-burning flame, in colder ocean regions, they are more like fireworks.

"There, species evolve relatively quickly, but each glaciation period clears out much of what was there before," Miller said. "Once the glaciers recede, they leave empty niches waiting to be repopulated by new species."

Frequent environmental upheaval results in overall biodiversity being lower in colder ocean regions.

In the Coral Triangle, on the other hand, new species have evolved less rapidly, but because conditions have been much more stable over long periods of geological time, they were more likely to stick around once they appeared and slowly accumulate to the biological diversity we see today.

"This suggests that a region may need long-term stability to accumulate high species diversity," Miller said. "According to our study, the magic number appears to be 30 million years."

In the Central-Indo Pacific, plate tectonics created a wide platform of shallow ocean, while its central location made it a target for colonization. It was the right place at the right time for the fishes that colonized the region.

"Things haven't changed much there in the past 30 to 35 million years," Miller said. "In contrast, other marine regions, such as the Caribbean, underwent periods of instability and isolation, and therefore fewer colonizations and higher rates extinction of the lineages that were there previously - all those factors add up to less evolutionary time."

For the study, Miller and her team used distribution data of almost all spiny ray-finned fishes - 17,453 species in total, representing about 72 percent of all marine fishes and about 33 percent of all freshwater fishes. They used several different statistical methods to reconstruct the causes of underlying species richness patterns among global marine regions.

To disentangle how marine fish diversity unfolded over time, the team then used a published evolutionary tree of this fish group and performed biogeographic reconstructions.

"Biogeographic reconstructions help us understand where ancestors were living at various places back in time, based on where species live today and how they are related," Miller said. "It's easy if you only compare two species that live in the same place, but if you have thousands of species and go back further and further in time, more ancestors come into play and things become more difficult."

Evolutionary biologists rely on sophisticated computer algorithms to manage and interpret the extremely large data sets. The method used by Miller and her team created many hypothetical scenarios of where species evolved. The researchers then used these scenarios to test how different models explain today's biodiversity.

"It's like drawing family histories, each slightly different," Miller said. "You start out with analyses and repeat them hundreds of times, each time based on some possible history to try and encompass uncertainty to see how they play out. In our study, it turned out the uncertainty is low, which is reassuring. It means it's a really robust result."

The general idea that patterns of diversity can be explained by how long a group has been present rather than how quickly they proliferate is relevant to lots of different systems, according to the researchers. For example, biologists have observed that the timing of colonization explains the high diversity of certain animal groups in terrestrial ecosystems, such as treefrogs in the Amazon rainforests, salamanders in the Appalachian Mountains and lizards in the desert Southwest.

"The general takeaway is that these patterns of high diversity may take tens of millions of years to arise, but can be wiped out in a few years by human impacts," said John Wiens, senior author of the paper and a professor in the UA Department of Ecology and Evolutionary Biology. "Unfortunately, the high diversity of reef fish in the Coral Triangle may soon disappear because of the impacts of human-induced climate change on coral reefs. The diversity that gets lost in the next few years may take tens of millions of years to get back."

Source: University of Arizona [November 09, 2018]

Re-inventing the hook: Orangutans spontaneously bend straight wires into hooks to fish for food

By: Thomas Schmitt Attorney on November 09, 2018 / comment : 0 Borneo, Endangered Species, Indonesia, Natural Heritage, Psychology, Sumatra, Wildlife

The bending of a hook into wire to fish for the handle of a basket is surprisingly challenging for young children under eight years of age. Now cognitive biologists and comparative psychologists from the University of Vienna, the University of St Andrews and the University of Veterinary Medicine Vienna around Isabelle Laumer and Alice Auersperg studied hook tool making for the first time in a non-human primate species - the orangutan. To the researchers' surprise the apes spontaneously manufactured hook tools out of straight wire within the very first trial and in a second task unbent curved wire to make a straight tool.

Wild male orangutan [Credit: © Graham L. Banes]

Human children are already proficient tool-users and tool-makers from an early age on. Nevertheless, when confronted with a task, which required them to innovate a hooked tool out of a straight piece of wire in order to retrieve a basket from the bottom of a vertical tube, the job proved more challenging for children than one might think: Three to five-year-old children rarely succeed and even at the age of seven less than half of them were able to solve the task. Only at the age of eight the majority of children was able to innovate a hook-tool. Interestingly children of all tested age classes succeeded when given demonstrations on how to bend a hook and use it. Thus, although young children apparently understand what kind of tool is required and are skilled enough to make a functional tool, there seems to be a cognitive obstacle in innovating one.

Cognitive biologists and comparative psychologists from the University of Vienna, the University of St Andrews and the University of Veterinary Medicine in Vienna around Isabelle Laumer now tested for the first time a primate species in the hook-bending task. "We confronted the orangutans with a vertical tube containing a reward basket with a handle and a straight piece of wire. In a second task with a horizontal tube containing a reward at its centre and a piece of wire that was bent at 90°", explains Isabelle Laumer who conducted the study at the Zoo Leipzig in Germany. "Retrieving the reward from the vertical tube thus required the orangutans to bent a hook into the wire to fish the basket out of the tube. The horizontal tube in turn required the apes to unbent the bent piece of wire in order to make it long enough to push the food out of the tube."

Male orangutan using a stick tool [Credit: © Alice Auersperg]

Several orangutans mastered the hook bending task and the unbending task. Two orangutans even solved both tasks within the first minutes of the very first trial. "The orangutans mostly bent the hooks directly with their teeth and mouth while keeping the rest of the tool straight. Thereafter they immediately inserted it in correct orientation, hooked the handle and pulled the basket up", she further explains.

Orangutans share 97% of their DNA with us and are among the most intelligent primates. They have human-like long-term memory, routinely use a variety of sophisticated tools in the wild and construct elaborate sleeping nests each night from foliage and branches. Today orangutans can only be found in the rainforests of Sumatra and Borneo. Like all four great ape species, orangutans are listed as critically endangered (IUCN, Red List). "Habitat loss due to extensive palm-oil production, illegal wildlife trade and poaching are the major threats. Palm oil is the most widely used vegetable oil in the world. As long as there is a demand for palm oil and consumers keep buying products that contain palm oil, the palm industry thrives. According to a 2007 survey by the United Nations Environment Program (UNEP) orangutans will be extinct in the wild within two decades if current deforestation trends continue", says Isabelle Laumer.

Orangutans in the wild [Credit: © Graham L. Banes]

"The hook-bending task has become a benchmark paradim to test tool innovation abilities in comparative psychology", says Alice Auersperg from the University of Veterinary Medicine in Vienna. "Considering the speed of their hook innovation, it seems that they actively invented a solution to this problem rather than applying routined behaviours."

"Finding this capacity in one of our closest relatives is astonishing. In human evolution hook tools appear relatively late. Fish hooks and harpoon-like, curved objects date back only approximately 16.000- 60.000 years. Although New Caledonian crows use hooks with regularity, there are a few observations of wild apes, such as chimpanzees and orangutans, that use previously detached branches to catch and retrieve out-of-reach branches for locomotion in the canopy. This branch-hauling tools might represents one of the earliest and simplest raking tools used and made by great apes and our ancestors", says Josep Call of the University of St Andrews.

So why struggle younger children with this task? "Follow-up studies showed that childrens difficulty with independently finding the solution cannot be explained by fixedness on unmodified tools, impulsivity nor by not being able to change the strategy. The hook bending task represents a complex problem, for which several unrewarded steps must be performed while keeping the final goal in mind", explains Isabelle Laumer. "Interestingly, complex problem solving has been associated to certain areas of the medial prefrontal cortex, which mature later in the child development. This explanation, besides children´s strong reliance on social learning might explain their success at a later age."

The study is published in Scientific Reports.

Source: University of Vienna [November 09, 2018]

Oldest known figurative cave art discovered in Borneo

By: Thomas Schmitt Attorney on November 07, 2018 / comment : 0 Archaeology, Asia, Borneo, Indonesia, South East Asia

Griffith University researchers have dated cave paintings in Borneo to as early as 40,000 years ago, showing that these enigmatic artworks are among the world’s oldest examples of figurative depiction.

Composition of mulberry-coloured hand stencils superimposed over older reddish/orange hand stencils.  The two styles are separated in time by at least 20,000 years [Credit: Kinez Riza]

This finding adds to the mounting view that cave art – one of the most important innovations in human cultural history – did not arise in Europe as long believed, and that ‘ice age’ artists in Southeast Asia played a key role in its development.

Since the 1990s, caves in remote and rugged mountains of East Kalimantan, an Indonesian province of Borneo, have been known to contain prehistoric paintings, drawings, and other imagery, including thousands of depictions of human hands (“stencils”), animals, abstract signs and symbols, and related motifs.

These near-inaccessible artworks are now known to be far older than previously thought, according to a study led by Griffith’s Associate Professor Maxime Aubert, along with Indonesia’s National Research Centre for Archaeology (ARKENAS), and the Bandung Institute of Technology (ITB), published in Nature.

Composition of mulberry-coloured hand stencils from East Kalimantan, Indonesian Borneo.  This particular style of hand stencil dates to the height of the Last Glacial Maximum  about 20,000 years ago [Credit: Kinez Riza]

Associate Professor Aubert’s team reports Uranium-series dates obtained from calcium carbonate samples collected from the Kalimantan cave art, providing the first reliable estimates for the approximate time of rock art production.

“The oldest cave art image we dated is a large painting of an unidentified animal, probably a species of wild cattle still found in the jungles of Borneo – this has a minimum age of around 40,000 years and is now the earliest known figurative artwork,” Associate Professor Aubert said.

The Kalimantan stencil art was shown to be similar in age, suggesting that a Palaeolithic rock art tradition first appeared on Borneo between about 52,000 and 40,000 years ago.


Dating also indicated that a major change occurred within this culture around 20,000 years ago, giving rise to a new rock art style (including rare portrayals of humans) at a time when the global ice age climate was at its most extreme.

“Who the ice age artists of Borneo were and what happened to them is a mystery,” said team co-leader Dr Pindi Setiawan, an Indonesian archaeologist and lecturer at ITB. Setiawan has studied the art since its discovery, and, along with ARKENAS rock art expert Adhi Agus Oktaviana, leads expeditions to the Kalimantan caves.

“The new findings illustrate that the story of how cave art emerged is complex,” Oktaviana said.

Human figures from East Kalimantan, Indonesian Borneo. This style is dated to at least 13,600 years ago  but could possibly date to the height of the last Glacial Maximum 20,000 years ago  [Credit: Pindi Setiawan]

Europe has long been seen as the centre for cave art development. But although Borneo is the Earth’s third largest island, throughout most of the ice age it actually formed the easternmost tip of the vast continental region of Eurasia – at the western extremity of this 13,000 km-wide landmass was Europe.

“It now seems that two early cave art provinces arose at a similar time in remote corners of Palaeolithic Eurasia: one in Europe, and one in Indonesia at the opposite end of this ice age world,” said Associate Professor Adam Brumm, a Griffith archaeologist also involved in the study.

A 2014 Nature paper published by Associate Professors Aubert and Brumm (with ARKENAS) revealed that similar cave art appeared in the island of Sulawesi about 40,000 years ago.

The worlds oldest figurative artwork from Borneo dated to a minimum of 40,000 years  [Credit: Luc-Henri Fage]

Sulawesi lies off the edge of Eurasia and is a vital stepping-stone between Asia and Australia.

“Our research suggests that rock art spread from Borneo into Sulawesi and other new worlds beyond Eurasia, perhaps arriving with the first people to colonise Australia,” Associate Professor Aubert said.

Read The Conversation article

Source: Griffith University [November 07, 2018]

Despite Indonesian government claims, orangutan populations have not increased

By: Thomas Schmitt Attorney on November 05, 2018 / comment : 0 Ecosystems, Endangered Species, Indonesia, Natural Heritage, Wildlife

Orangutan populations are still declining rapidly, despite claims by the Indonesian Government that things are looking better for the red apes. In the journal Current Biology, a team of scientists including Maria Voigt of the German Centre for Integrative Biodiversity Research (iDiv) and the Max Planck Institute for Evolutionary Anthropology criticise the use of inappropriate methods for assessing management impacts on wildlife trends. The researchers call for scientifically sound measures to be employed in order to ensure that wildlife monitoring provides reliable numbers.

Scientists call for the employment of scientifically sound methods for monitoring orangutan populations [Credit: HUTAN-KOCP]

A recent report by the Government of Indonesia states that orangutan populations have increased by more than 10% from 2015 to 2017. These numbers are criticised in an article published in the current issue of Current Biology. Lead author Erik Meijaard from the Center of Excellence for Environmental Decisions at the University of Queensland and director of Borneo Futures in Brunei explains: "These numbers are in strong contrast with other recent publications about orangutan status and trends."

According to the authors, over the past ten years alone, the number of Bornean orangutans has declined by at least 25%, representing a loss of more than 100,000 individuals since the year 1999. Sumatran orangutans and the recently described Tapanuli orangutan lost more than 60% of their forest habitat between 1985 and 2007, and their populations are expected to further decline by 11 to 27% until 2020.

The scientists reiterate that the latest scientific data show how the survival of the three orangutan species continues to be seriously threatened by deforestation and killing; all are "Critically Endangered" under the IUCN Red List.

Orangutan populations have been declining dramatically [Credit: Serge Wich]

How can there be such a mismatch between what the government states and what independent scientists have published about the orangutan conservation status? The paper's authors offer a few suggestions:

The government monitoring methods focus on nine sampled populations. These populations represent less than 5% of the Bornean and Sumatran orangutan ranges, and zero percent of the Tapanuli orangutan range. All monitoring sites are within protected areas, whereas the majority of orangutans occur in non-protected lands like oil palm plantations, private gardens, community lands, and logging concessions.

Habitat conditions and threats differ vastly across these and thus population trends observed in a few protected sites cannot credibly inform the status of all three species. The government-reported increases are also highly unlikely considering known reproductive rates and ongoing killing observed in many populations.

Senior author Maria Voigt of the iDiv research centre and the Max Planck Institute for Evolutionary Anthropology highlights the clear need to improve collaboration and data sharing between scientists and the Indonesian government authorities: "It appears that the government isn't always aware of the latest published conservation science," Voigt notes. "Both parties need to increase their engagement."

Forests are being converted into oil palm plantations. This is a major threat to orangutans [Credit: HUTAN-KOCP]

According to Voigt, better collaboration between government, non-governmental organisations and scientists is especially important now that Indonesia is developing its new action plan for orangutan conservation for the years 2018 to 2027. "It is critical to ensure that the best data and methods are used to determine which conservation strategies should be applied and where," Voigt explains. "The choice of possible conservation strategies, such as forest protection, law enforcement, education, community engagement or orangutan rescues and rehabilitation depends on local orangutan trends, survival rate and pressures. This is what science can bring to the table."

"I am optimistic," says first author Erik Meijaard. "I still believe that by bringing together science, policy, land-use and species management we can save the orangutan and prevent its extinction in the wild."

And there is hope that this can help the remaining orangutans. The new moratorium on oil palm licenses by Indonesian President Jokowi, for example, presents a real opportunity for saving the 10,000 orangutans that currently occur in areas allocated to oil palm by giving them permanent forest protection status.

It does, however, require a change of conservation mindset. "We need to learn how to better manage and protect those populations that are found outside of formally protected areas," Maria Voigt says. "An improvement of the status of the three orangutan species can only be achieved with the genuine collaboration and engagement of all parties that have a stake in these non-protected lands: the agriculture industry, local communities and local governments."

Source: German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig [November 05, 2018]

Megalithic statues discovered in Srobu site, Papua

By: Thomas Schmitt Attorney on November 01, 2018 / comment : 0 Archaeology, Asia, Indonesia, Papua New Guinea, South East Asia

An archaeologist from Papua Archaeological Center, Erlin Novita Idje Djami, together with her team, has found two megalithic statues of Polynesian style on the Mount Srobu site located in Abepantai Village, Abepura District, Jayapura City, Papua Province.

Credit: Satusuaraexpress

"In 2018, we have made a spectacular discovery, namely two megalithic statues of Polynesian style. But, I prefer to call them the megalithic statues of Srobu Papua," she stated here on Wednesday.

She added that the discovery was extraordinary and unique because the statues were different from those found in other areas in Papua.

The two statues are one metre high and weigh around 50 to 60 kilograms.

"The two statues and other cultural materials are being analyzed at the Papua Archaeological Center," Djami noted.

She revealed that the Srobu Mountain Site is one of the important archaeological sites in Jayapura city. This site is located on a cape in Youtefa Gulf. This area is a place for some locals to look for shells as raw material to make lime that is used for chewing betel.

"In February 2014, we got information that there were bones found in Srobu Mountain. The locals guessed the bones were those of Japanese soldiers," she remarked, adding that the Papua Archaeology Centre, together with the Provincial Culture and Tourism Office, later went to the location to check the information.

"Surprisingly, we not only found bones but also various cultural objects, such as pottery fragments, stone tools, and mollusks shells. I can say that this is one of the great archaeological sites in Papua," Djami revealed.

After that, the Papua Archaeology Centre set up a plan to conduct the first research in 2014.

"That year, we carried out a surface survey but did not cover all areas. We also carried out excavations and found a number of stone axe artefacts, oval axes, and tools made of shells, beside pottery with beautiful decoration, "he added.

According to E Djami , the findings of cultural objects characterize a culture from prehistoric times.

"From the dating, the Mount Srobu site has been inhabited since 3,780 before present or BP. This means the site is from Neolithic era, showing that Papua already has an extraordinary culture," she noted.

In addition to Neolithic culture, in 2015, the researchers also found megalithic relics, in the form of menhirs and dolmens, which were neatly arranged on the ground.

"We will continue this research until this year. So, every year, our research on the Srobu Site discovers unique new things that illustrate a cultural revolution at that location," she explained.

He hoped that the Srobu Site could become one of the historical tourist destinations in Jayapura City in particular, and Papua, in general.

"This Srobu Site is an open prehistoric settlement. Neolithic settlements in Indonesia are very few, but in Papua, the findings of this culture are extraordinary," she elaborated, adding that Srobu Site is more unique than all the Neolithic or prehistoric settlement sites in Papua.

Source: AntaraNews [November 01, 2018]

Study finds most likely route of first humans into Australia

By: Thomas Schmitt Attorney on October 31, 2018 / comment : 0 Anthropology, Australasia, Genetics, Indonesia, Papua New Guinea

A new study from ANU indicates the most likely route the ancestors of Aboriginal people took to enter Australia for the first time tens of thousands of years ago.

Gwion Gwion rock art site, Kimberley, WA [Credit: Peter Eve]

Co-lead researcher Shimona Kealy said these people probably travelled through Indonesia's northern islands, into New Guinea and then Australia, which were part of a single continent between 50,000 and 70,000 years ago, when sea levels were 25-50 metres below the current level.

"We've created a treasure map of sorts with the likely route across land and water that these incredible people took to reach Australia," said Ms Kealy, a Ph.D. scholar at the School of Culture, History and Language and an Associate Investigator at the ARC Centre of Excellence for Australian Biodiversity and Heritage at ANU.

"We've circled all of the islands that we want to explore further to find archaeological evidence to test if this is in fact the path that they took.

"Archaeologists have yet to explore most of Indonesia's northern islands for human settlements predating the oldest sites found in Australia. These islands could hold the key to the mystery of how the first humans made it to Australia's shores."

The findings challenge a popular theory that these early adventurers travelled from Southeast Asia, through Indonesia and Timor and then across sea to reach Australia's shores and land that is part of the Northern Territory today.

Map of island Southeast Asia showing possible routes to Australia [Credit: Shimona Kealy et al. 2018]

The study modelled the least-cost path from Southeast Asia to Australia, by considering factors such as difficulty to travel up slopes, visibility at sea, access to fresh water along the many potential pathways and the sophistication of maritime technology at the time.

Ms Kealy said the oldest dates for human occupation on the Australian-New Guinea continent (known as Sahul) represented the earliest, indirect evidence for sea faring by humans anywhere in the world.

"This study helps to tell the Australian story, particularly for Indigenous people, and acknowledges the bravery, innovation and maritime technologies and skills of these early modern humans," Ms Kealy said.

The islands directly north and west of Sahul (known as Wallacea) were never connected to the mainland, requiring multiple successful water crossings east from mainland Southeast Asia (Sunda).


"These people hopped their way along these islands, probably looking for a place to live where they would have access to reliable food staples and other resources—the visibility between islands would have been very favourable in terms of enabling this adventurous spirit," Ms Kealy said.

Co-lead researcher Professor Sue O'Connor from ANU said the proposed alternative route through Timor onto the northwest coast of Australia is now seen as less likely as a result of this study's least-cost pathway modelling.

"The suggested route through Timor is also considered less likely given comprehensive archaeological evidence indicates the earliest human settlements in Timor are much younger than those found in Madjedbebe in Arnhem Land in the Northern Territory," said Professor O'Connor, a researcher at the School of Culture, History and Language and a Chief Investigator at the ARC Centre of Excellence for Australian Biodiversity and Heritage at ANU.

The study is published in the Journal of Human Evolution.

Source: Australian National University [October 31, 2018]

Archaeologists find the earliest use of nutmeg as a food

By: Thomas Schmitt Attorney on October 03, 2018 / comment : 0 Archaeology, Asia, Indonesia, South East Asia

As all things pumpkin spice arrive in grocery store aisles and on restaurant menus, a new study published in the journal Asian Perspectives describes the earliest-known use of nutmeg as a food ingredient.

Burke Museum Archaeology Curator Peter Lape (left) and Daud Tanudirjo (right) excavating a layer at the site with the earliest known cooking use of nutmeg [Credit: Andrew Lawless]

Found at an archaeological site on Pulau Ay, a small island in the Banda Islands, central Maluku, Indonesia, the nutmeg was found as residue on ceramic potsherds and is estimated to be 3,500 years old -- about 2,000 years older than the previously known use of the spice.

The study and two excavations in 2007 and 2009 were led by Peter Lape, professor of anthropology at the University of Washington and curator of archaeology at the Burke Museum, in collaboration with colleagues from Universitas Gadjah Mada in Indonesia, the University of New South Wales in Australia and others.

The Pulau Ay archaeological site was occupied from 2,300 to 3,500 years ago, with animal bones, earthenware pottery, stone tools, and post molds of possible housing structures found. The variety of artifacts discovered provides evidence of changes in how people utilized marine food resources, pottery and domestic animals over time.

Over the first 500 years at the site, people shifted from a predominately fish-based diet to primarily eating domesticated pigs. In addition, pottery was initially thin-walled vessels adapted for storage of liquids that may have allowed people to survive on this water-poor island. A few hundred years later, thicker-walled pottery better adapted for cooking appears along with pig bones.

A potsherd found at the Pulau Ayarchaeological site. It was one of several pottery pieces containing traces of foods,including the earliest-known use ofnutmeg [Credit: Peter Lape/University of Washington]

"This site shows us how people adapted to living on these small tropical islands in stages, from occasional use as fishing camps to permanent occupation," Lape said. "It's also fascinating to see such early use of nutmeg, a spice that changed the world a few thousand years later."

It was on the pottery where Lape's co-authors Judith Field and Adelle Coster found not only the nutmeg, but also residue from six other plants including sago and purple yam. These plants could have been collected from wild plants, or possibly cultivated through farming.

Pulau Ay is a small island lacking both indigenous land mammals and surface water. It likely would not have supported a permanent human population that did not have the technological advantages of domestic animals and water storage.

However, by surveying additional archaeological sites, the study's authors suggest that the island was regularly visited by people targeting its rich marine reef resources for several thousand years before more permanent populations were established in the early Neolithic, the later part of the Stone Age. The most likely homeland for these visitors is the nearest large island of Seram, 100 kilometers to the east. People who possessed sufficient knowledge of Pulau Ay and the seafaring skills to make regular return trips there would seem to be likely candidates for the first Neolithic settlers as well.

Benteng (Fort) Nassau was built in 1609 and was the first Dutch fort built on Banda Naira Island, the main island of the Banda Islands, part of Maluku in Indonesia. It was built to control the trade of nutmeg, which was only available from the Banda Islands at the time [Credit: Andrew Lawless]

Sometime around 2,300 years ago, the site was largely or totally abandoned, and no other sites in the Banda Islands have so far been found that date to the period between 2,300 and 1,500 years ago. Future work aims to answer why these remote islands, which attracted the settlement of people who were quite connected to other places before and after this period, would have been abandoned for 800 years.

Studies of sites like this one can help illuminate the complex cultural processes at work during the Neolithic period, which saw the introduction of many new plants, animals and technologies to the islands of Southeast Asia. The results from this site show that these changes did not happen all at once, but rather were gradually adopted and adapted to allow people to utilize these tropical island seascapes in new ways.

As for the nutmeg, understanding its earliest origins of human use helps connect the dots to later international trades. By the 14th century (and possibly earlier), long-distance traders were traveling to Banda to obtain nutmeg; this valuable spice brought the Banda Islands international renown during the early modern era.

The find provides a new perspective on a key ingredient that is still a valuable commodity today--especially in a multi-billion dollar industry of fall-themed foods and beverages.

Author: Andrea Godinez | Source: University of Washington [October 03, 2018]

Napoleon's defeat at Waterloo caused in part by Indonesian volcanic eruption?

By: Thomas Schmitt Attorney on August 22, 2018 / comment : 0 Earth Science, Europe, Geology, Indonesia, Palaeoclimate, Palaeontology

Electrically charged volcanic ash short-circuited Earth's atmosphere in 1815, causing global poor weather and Napoleon's defeat, says new research.

Napoleon’s retreat from the Battle of Waterloo. Image: After a painting by Steuben [Credit: Hulton Archive/Getty Images]

Historians know that rainy and muddy conditions helped the Allied army defeat the French Emperor Napoleon Bonaparte at the Battle of Waterloo. The June 1815 event changed the course of European history.

Two months prior, a volcano named Mount Tambora erupted on the Indonesian island of Sumbawa, killing 100,000 people and plunging the Earth into a 'year without a summer' in 1816.

Now, Dr Matthew Genge from Imperial College London has discovered that electrified volcanic ash from eruptions can 'short-circuit' the electrical current of the ionosphere -- the upper level of the atmosphere that is responsible for cloud formation.

The findings, published in Geology, could confirm the suggested link between the eruption and Napoleon's defeat.

Dr Genge, from Imperial's Department of Earth Science and Engineering, suggests that the Tambora eruption short-circuited the ionosphere, ultimately leading to a pulse of cloud formation. This brought heavy rain across Europe that contributed to Napoleon Bonaparte's defeat.

The paper shows that eruptions can hurl ash much higher than previously thought into the atmosphere -- up to 100 kilometres above ground.

Dr Genge said: "Previously, geologists thought that volcanic ash gets trapped in the lower atmosphere, because volcanic plumes rise buoyantly. My research, however, shows that ash can be shot into the upper atmosphere by electrical forces."


A series of experiments showed that that electrostatic forces could lift ash far higher than by buoyancy alone. Dr Genge created a model to calculate how far charged volcanic ash could levitate, and found that particles smaller than 0.2 millionths of a metre in diameter could reach the ionosphere during large eruptions.

He said: "Volcanic plumes and ash both can have negative electrical charges and thus the plume repels the ash, propelling it high in the atmosphere. The effect works very much like the way two magnets are pushed away from each other if their poles match."

The experimental results are consistent with historical records from other eruptions.

Weather records are sparse for 1815, so to test his theory, Dr Genge examined weather records following the 1883 eruption of another Indonesian volcano, Krakatau.

The data showed lower average temperatures and reduced rainfall almost immediately after the eruption began, and global rainfall was lower during the eruption than either period before or after.

He also found reports of ionosphere disturbance after the 1991 eruption of Mount Pinatubo, Philippines, which could have been caused by charged ash in the ionosphere from the volcano plume.

In addition, a special cloud type appeared more frequently than usual following the Krakatau eruption. Noctilucent clouds are rare and luminous, and form in the ionosphere. Dr Genge suggests these clouds therefore provide evidence for the electrostatic levitation of ash from large volcanic eruptions.

Dr Genge said: "Vigo Hugo in the novel Les Miserables said of the Battle of Waterloo: 'an unseasonably clouded sky sufficed to bring about the collapse of a World.' Now we are a step closer to understanding Tambora's part in the Battle from half a world away."

Author: Caroline Brogan | Source: Imperial College London [August 22, 2018]