Tag Archives: tool use

New Caledonian crow that made a paper card from scratch in order to receive a reward. Credit: Sarah Jelbert

New Caledonian crows can make tools from memory

New Caledonian crows are quite possibly the smartest birds out there. Their most impressive intellectual feat is their uncanny tool-making ability. Now, a new study shows that the crows are capable of fashioning tools from memory, which was thought to be impossible to do for a bird.

New Caledonian crow that made a paper card from scratch in order to receive a reward. Credit: Sarah Jelbert

New Caledonian crow that made a paper card from scratch in order to receive a reward. Credit: Sarah Jelbert

Corvids, the cosmopolitan family of oscine passerine birds that numbers crows, ravens, and rooks, are really smart. They play ahead, remember human faces, and solve puzzles.

New Caledonian crows — which live on the remote tropical island of New Caledonia in the South Pacific — are known for using twigs to stir beetle grubs and other small prey out of hiding places. They’re able to do just fine with straight twigs, but sometimes, they fashion hooked twigs — all using just their beaks and feet.

In another mind-boggling example, researchers have witnessed not one, but two crows inserting sticks into objects to carry both at once. Some of these objects were too cumbersome to carry by beak alone, which is telling of the birds’ ingenuity.

But among all of these achievements, one study published in 2002 documented a behavior that has been puzzling scientists ever science. In the study, the authors followed a captive New Caledonian crow called Betty thatt took a piece of wire, bent it into a hook, then retrieved some food otherwise out of reach. Betty used the wire after another crow had taken all the available hooks.

All of this made Alex Taylor, a researcher at the University of Auckland in New Zealand, very curious. How were these birds learning such a sophisticated behavior? The New Caledonian crows’ behavior suggested that the birds were using a sort of “mental template matching,” forming a mental picture of the tool-making process they’d seen in another bird, then copying it. This is also how humans learn new skills, through cultural transmission.

“Under the mental template matching hypothesis, New Caledonian crow tool designs could be passed on to subsequent generations if an individual used or observed the products of tool manufacture (such as their parents’ tools), formed a mental template of this type of tool design (a mental representation of some or all of the tool’s properties), and then reproduced this template in their own manufacture,” the authors of the new study wrote.

Taylor and colleagues devised an experiment to test their hypothesis, involving eight crows that were trained to drop bits of paper into a vending machine. The New Caledonian crows learned that they would be rewarded with food only when they introduced cards of a specific size, either large ones measuring 40 x 60 mm or small cards measuring 15 x 25 mm.

After this initial round of training, all the pieces of papers were taken away and replaced with a single large sheet of paper that couldn’t fit into the vending machine. The scientists then watched with their jaws dropping how the birds tore up the large piece of paper to fashion smaller pieces that matched the sizes that would earn them a reward. According to Taylor and colleagues, this is an example of “manufacturing by subtraction.”

This suggests that the crows formed a mental image of the desired object, which they then materialize into a new tool, the authors reported in Scientific Reports. Now, the researchers think that crows might also possess the ability to improve tools over time, something which they hope to test soon.

Chimps use dipping sticks to harvest water from tree holes. They’re the only ones that can reach the resource

https://www.youtube.com/watch?v=BVesrNhuJTQ

Camera traps installed at the Comoe Chimpanzee Conservation Project in the Ivory Coast caught our closest relatives using tools in a new way for the first time. The clever chimps crafted dipping sticks by chewing one of the ends, turning a simple twig into a brush. The sticks are primarily used to harvest water from deep water holes. Only the chimps — and no other animal — seem to be able to access this kind of water resource, a clear competitive edge.

“The longer the brush, the more water they collect,” said Juan Lapuente, a lead researcher at the Comoe Chimpanzee Conservation Project.

Like humans, chimps use tool to make their lives easier. In 1960, Jane Goodall discovered that a chimp called David Greybeard would select twigs, strip their leaves, then use it to poke termite mound and collect the delicious insects. Since then, researchers have documented various other instances of tool use and, most strikingly, tool manufacturing. Josep Call from the Max Planck Institute for Evolutionary Biology in Germany said chimps who ‘fish’ for termites “complete tool manufacture by modifying the end into a ‘paint brush’ tip by pulling the stem through their teeth, splitting the probe lengthwise by pulling off strands of fiber, or separating the fibers by biting them.”

What’s more tool use and gestures are culturally based down, as documented by Dr. Catherine Hobaiter from the University of St. Andrews who witnessed how elder chimps in a community taught others how to use moss sponges to drink water.

Modified sticks remain the chimps favorite and most accessible tool. For instance, brush-tipped sticks are often used to harvest honey from bees’ nests, a practice common among many chimp populations in Africa. Sticks for accessing water, however, have only been witnessed in Comoe populations. This led the researchers to believe that these particular chimps have what they call a “drinking culture” — a practice shared among the group that helps them live through the dry season, as reported in the American Journal of Primatology.

human hands ancestor

Early human ancestors used their hands much in the way as we do

After analyzing key hand bone fragments from fossil records, a team of anthropologists conclude that pre-homo  human ancestral species, such as Australopithecus africanus, used a hand posture very similar to that of modern humans. Considering fossil tools used for scrubbing off meat as old as 3.3 million years have been found, it may just be that our early ancestors weren’t all that different from good ol’ superior homo sapiens sapiens. Well, as far as hands go at least.

A handy ancestor

human hands ancestor

Like humans, chimps have opposable thumbs and opposable big toes which allow them to grip things with their feet. Yet, our close cousins don’t possess what scientists call a habile hand, since theirs haven’t been freed from walking requirements. As such, the evolution of the opposable or prehensile thumb is recognized by anthropologists as being linked with two key evolutionary transitions in hand use: a reduction in arboreal climbing and the manufacture and use of stone tools.

[RIDDLE] Which came first: the dexterous hand or the agile foot?

Matthew Skinner and Tracy Kivell of the Max Planck Institute for Evolutionary Anthropology and the University of Kent used new techniques to reveal how fossil species were using their hands by examining the internal spongey structure of bone called trabeculae. These bones quickly reshape during the lifetime to adapt to various stresses. So, for humans at least, you can tell whether a person is a carpenter, construction worker or a computer programmer, just by looking at the trabeculae.

The first metacarpals of a chimp, the fossil australopiths, and a human (top row). The bottom row constists of images from micro-computertomography-scans of the same specimens, showing a cross-section of the trabecular structure inside. © Tracy Kivell

The first metacarpals of a chimp, the fossil australopiths, and a human (top row). The bottom row constists of images from micro-computertomography-scans of the same specimens, showing a cross-section of the trabecular structure inside. © Tracy Kivell

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A human forceful precision grip, grasping a Australopithecus africanus first metacarpal of the thumb. © Tracy Kivell & Matthew Skinner

A human forceful precision grip, grasping a Australopithecus africanus first metacarpal of the thumb.
© Tracy Kivell & Matthew Skinner

First, the researchers compared the trabeculae of humans and chimps. As expect, key differences were identified. The chimpanzee clearly can not adapt to human-like hand posture, lacking the ability for forceful precision gripping between thumb and fingers (e.g. like turning a key). Remarkably, a hominid ancestor called Australopithecus africanus, who lived some 3 to 2 million years ago, has a human-like trabecular bone pattern in the bones of the thumb and palm (the metacarpals) consistent with forceful opposition of the thumb and fingers typically adopted during tool use.

What makes this so important is that traditionally anthropologists believe Homo habilis, also known as “Handy Man,” was the first maker of stone tools. The models support previous archaeological evidence for stone tool use among australopiths, meaning the first tool use could be pushed back much earlier than previously thought – we just have to wait for evidence to surface, if any survived the test of time. What’s clear, though, is that our early ancestors used human-like hand postures frequently and earlier than currently estimated.

“This new evidence changes our understanding of the behaviour of our early ancestors and, in particular, suggests that in some aspects they were more similar to humans than we previously thought”, says Matthew Skinner of the Max Planck Institute for Evolutionary Anthropology and the University of Kent.

“There is growing evidence that the emergence of the genus Homo did not result from the emergence of entirely new behaviours but rather from the accentuation of traits already present in Australopithecus, including tool making and meat consumption”, says Jean-Jacques Hublin, director at the Max Planck Institute for Evolutionary Anthropology.

The original skull (without upper teeth and mandible) of a 2,1 million years old Australopithecus africanus specimen so-called “Mrs. Ples” discovered in South Africa. Image: Archaeodontosaurus/Wikipedia (CC BY-SA 4.0)

The original skull (without upper teeth and mandible) of a 2,1 million years old Australopithecus africanus specimen so-called “Mrs. Ples” discovered in South Africa. Image: Archaeodontosaurus/Wikipedia (CC BY-SA 4.0)

The results are published in Science.

Levallois Core from the Douro Basin, Portugal. José-Manuel Benito Alvarez

Stone tools evolved independent of ancient African cultures

Neanderthals were one of the early hominids who used  Levallois technique to make stone tools. Image: Prisma/UIG/Getty

Neanderthals were one of the early hominids who used Levallois technique to make stone tools. Image: Prisma/UIG/Getty

A breakthrough finding in Armenia where thousands of ancient cutting tools were found beautifully preserved casts doubt on a currently prevailing hypothesis that these were solely invented in Africa. The tools discovered are between 325,000 and 335,000 years old. The age suggests the ancient paleolithic cultures of the time that inhabited the region independently developed the sophisticated technique to produce them.

Independent thought and inventions across the ancient hominid world

Levallois Core from the Douro Basin, Portugal.  José-Manuel Benito Alvarez

Levallois Core from the Douro Basin, Portugal. José-Manuel Benito Alvarez

Early Stone Age populations made their tools by chipping away a stone until it turned into a desired shape – a cutting tool, arrow or spear tip etc. In the so-called Levallois technology, named after the Levallois-Perret suburb of Paris where it was first described, the toolmaker first chisels a suitably shaped core from a stone and then slices off flakes from it.  Raw blocks of stone are prepared by striking pieces off the edges until it is shaped something like a turtle shell: flat on the bottom and humped on the top. That shape permits the knapper to control the results of using applied force: by striking the top edges of the prepared core, the knapper can pop off a series of similarly sized flattish, sharp stone flakes which can then be used as tools. The technique was reckoned a leap forward in stone technology and behavioral modernity: the production method is in stages, and requires forethought and planning.

“The discovery of thousands of stone artefacts preserved at this unique site provides a major new insight into how Stone Age tools developed during a period of profound human behavioral and biological change,” said Dr. Simon Blockley from the Department of Geography at Royal Holloway.

“The people who lived there 325,000 years ago were much more innovative than previously thought, using a combination of two different technologies to make tools that were extremely important for the mobile hunter-gatherers of the time.

Lavallois technology was discovered throughout Europe and Eurasia, but because such tools in African had been dated as being much older than those found in other regions, many researchers were led to believe the technique first developed there and was then introduced in other parts of the world following a great migration.

levalloise_tool

Levallois and biface tools. Credit: Royal Holloway, University of London

The Nor Geghi site in present day Armenia, discovered in 2008, shakes this theory which was already doubtful. For instance, it doesn’t explain  why some Levallois tools found in Eurasia are smaller, or otherwise different, from African ones and relies on a unvoked an unproven migration of unknown hominids out of Africa.

“Our findings challenge the theory held by many archaeologists that Levallois technology was invented in Africa and spread to Eurasia as the human population expanded. Due to our ability to accurately date the site in Armenia, we now have the first clear evidence that this significant development in human innovation occurred independently within different populations,”  Blockley said.

Researchers led by Daniel Adler at the University of Connecticut in Storrs discovered thousands of cutting tools of various shapes and size trapped inside a flood plain sediment with volcanic ash, and preserved by two lava flows dated to 200,000 and 400,000 years ago. Using chemical methods, the researchers found the tools came from local source, although some used material from as far as 120km away.

“We wouldn’t have found this mixture if the Levallois technology had simply replaced the old method,” says Adler. “The communities probably worked out for themselves how to make bifacial tools and then it was a short step to the Levallois method.” He argues that the Stone Age people used both approaches flexibly.

Findings were reported in the journal Science.

Stone tools from Kharga Oasis, Egypt, one of the archaeological sites used in the study. Photograph reproduced with kind permission from The British Museum

Early modern humans were culturally diverse before leaving Africa

Stone tools from Kharga Oasis, Egypt, one of the archaeological sites used in the study. Photograph reproduced with kind permission from The British Museum

Stone tools from Kharga Oasis, Egypt, one of the archaeological sites used in the study. Photograph: The British Museum

Early modern human populations were culturally diverse and sometimes exchanged tools helped by river networks in a then savanna rich Sahara, according to the biggest ever comparative study of stone tools dating to between 130,000 and 75,000 years ago. At least four distinct populations, each relatively isolated from each other, have been identified as possessing distinct cultural practices.

Different tools, different cultures

The researchers from the University of Oxford, Kings College London and the University of Bordeaux took over 300,000 measurements of stone tools from 17 archaeological sites across North Africa, including the Sahara. Before early humans left Africa to settle communities in Eurasia, the Sahara we know today as a barren and inhospitable wasteland was considerably different. There were widespread areas filled with patchwork of savanna, grasslands and water, while the desert was interspersed between.

When assessing how ancient communities developed, it’s important to have a really accurate picture of how the climate was at the time, being an important element that puts things into context. With this in mind, the researchers studied climate models coupled with data about these ancient water courses, before finally matching these with new found data surrounding cutting tools. Because Africa’s extremely hot climate, ancient DNA has yet to be found and the most reliable artifacts that document the existence of early modern humans continue to be stone tools.

[RELATED] Neanderthals developed the first bone tools

Armed with this new found data, the researchers were able to infer the context in which the ancient populations made and used their tools. For the first time, tangible evidence was obtained that suggest early human communities were ‘budding’ with other populations along the ancient rivers and watercourses.

‘This is the first time that scientists have identified that early modern humans at the cusp of dispersal out of Africa were grouped in separate, isolated and local populations. Stone tools are the only form of preserved material culture for most of human history. In Africa, owing to the hot climate, ancient DNA has not yet been found. These stone tools reveal how early populations of modern humans dispersed across the Sahara just before they left North Africa. While different populations were relatively isolated, we were interested to find that when connected by rivers, they share similarities in their tool-making suggesting some interaction with one another,’ said Dr Eleanor Scerri, visiting scholar at the University of Oxford.

The researchers were careful to remove some of the causes that produce variability, but were not particularly tied to cultural characteristics, like raw materials.

‘Not much is known about the structure of early modern human populations in Africa, particularly at the time of their earliest dispersals into Eurasia. Our picture of modern human demography around 100,000 years ago is that there were a number of populations, varying in size and degree of genetic contact, distributed over a wide geographical area. This model of our population history supports other theories recently put forward that modern humans may have first successfully left Africa earlier than 60,000-50,000 years ago, which had been the common view among scholars. Our work provides important new evidence that sheds light on both the timing of early modern human dispersals out of Africa and the character of our interaction with other human species, such as Neanderthals,’ said Scerri.

Thanks to a growing body of evidence, the paradigm has shifted from asking whether or not humans originated from Africa, then spread out to the rest of the world, to the question ‘which of these distinct populations went in and out of Africa?’. A crucial next step involves fieldwork in areas such as the Arabian Peninsula to understand how these populations spread into Eurasia.

The findings were reported in the journal Quaternary Science Reviews.

gorrila_mother_aid

Gorilla mother uses makeshift ladder to help her young climb an obstacle [PHOTO]

While chimpanzees, which are our closest relatives sharing 98% of our genetic blueprint, are notorious for their widespread tool use, the same can’t be said about gorillas. The great apes have only been caught twice by researchers engaged in tool use. One used a stick to explore the depth of a muddy river and another turned a tree trunk to use it as a bridge. Finally we’ve got a third documented instance of gorilla tool use, and it’s most touching one too.

gorrila_mother_aid

(c) Science Mag

Deep in the Volcanoes National Park (Rwanda), an adult female was observed using a bamboo culm as a ladder for her offspring who couldn’t pass an obstacle otherwise. At first glace, the behavior might seem unintentional, however the researchers surprised the whole moment and saw that the mother reacted and came to aid with the makeshift ladder only after the offspring cried for help.  When the infant gorilla grabbed the lowered pole, the mother then grasped it more firmly, which allowed the infant to scurry up to join her. Beautiful!

The findings were reported in the journal Behavioural Processes

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