Dingoes are in the news lately: the infamous “a dingo ate my baby” case may be nearing its conclusion, 32 years after an Australian baby disappeared on a family camping trip; her mother, who long claimed the baby was stolen by a dingo, has been vindicated by an inquest this week noting that dingo attacks on humans have been well-documented in the intervening decades. But dingoes can use their cleverness for less gruesome purposes, as well. What is apparently the first tool use in a canid was observed recently, in a dingo named Sterling who really, really wanted to chew on something out of his reach.
As you can see in the video above, Sterling is trying to get a hold of a piece of food placed on his enclosure at the Dingo Discovery Research Center in Australia, after researchers caught him on tape yanking down a name tag from the same location. He has never been trained in any similar tasks, as far as the researchers know, but after jumping fails to get him close enough, he heads off to the back of the enclosure and hooks his teeth around the leg of a white table. Then the table begins to move, as Sterling pulls it towards the front of the enclosure. Once he gets it near the front, one of his compatriots jumps on, but then stands around doing nothing. Sterling hops on, pushes the offender out of the way, and, after several false starts, manages to walk his forelegs across the wire mesh to bring the food within his reach. He promptly tears his prize to the ground.
A few years ago, scientists observed that some bottle-nosed dolphins held sponges in their beaks as they poked around the ocean floor, flushing out fish they promptly gobbled up—and that mothers taught this trick to their daughters. In a follow-up study published yesterday, the scientists shed some light on why dolphins go to all this trouble: They’re after fatty, energy-rich fish on the seafloor, and the sponges let them scare up a snack without scraping their beaks on sharp rocks or coral.
In Australia’s Great Barrier Reef, a professional diver has photographed a blackspot turkfish smashing a clam against a rock to get the tasty treat on the inside—this appears to be the first documented case of a fish using a tool. But some people argue that this behavior, which is similar to a seagull cracking open a shell by dropping it onto a hard surface, does not constitute tool use because the “tool” is fixed and the animal never actually holds it.
See a nice round-up video of the news and the tool-use debate at HuffPost.
Image: Scott Gardner/Coral Reefs, DOI:10.1007/s00338-011-0790-y
Back in August, a study in Nature attempted to push back the date of human ancestors’ first known tool use by 800,000 years—from 2.6 million years ago to 3.4 million years ago. The evidence was a set of scratches on animal bones, which—according to the scientists behind the study—show evidence that the hominid species Australopithecus afarensis used cutting tools.
Not so fast, some anthropologists say. At the time of the Nature paper, researchers including the scientists behind the 2.6-million-year-old find said the newly found markings could have been caused by other means, including trampling by other animals. Now, in a study (in press) for today’s edition of the Proceedings of the National Academy of Sciences, a team of anthropologists makes a full case that the 3.4-million-year-old scratches are not evidence of tool use.
They argue that similar cuts can be produced when bones are gnawed by animals, trampled into rough ground, or even eroded by plants and fungi. Their conclusion: the marks on the Dikika bones were probably created by trampling and their age is uncertain. To them, the best evidence for butchery by human ancestors comes from stone tools recovered in Gona, Ethiopia, which are just 2.6 million years old.
Check out the rest of this post at Not Exactly Rocket Science.
Not Exactly Rocket Science: Human ancestors carved meat with stone tools almost a million years earlier than expected
80beats: Lucy’s Species May Have Used Stone Tools 3.4 Million Years Ago
DISCOVER: How Loyal Was Lucy?
According to one group of scientists, figuring out the answer required only a pair of high-tech gloves and a trained craftsman who could make both simple stone knives and more complicated hand axes. The craftsman wore gloves studded with electronic sensors that tracked his his hand movements. Lead researcher Aldo Faisal of Imperial College London found that simple and complex tools required the same amount of dexterity to produce.
“From these results, dexterity can be ruled out, and we can infer it has something to do with the complexity of the task,” says Faisal. Axes are made in several stages, which requires switching between tasks, suggesting that a higher level of complexity is required in the brain. [New Scientist]
A bountiful archaeological site in South Africa has given up another discovery showing humans becoming sophisticated tool users. According to a study out in the journal Science, 75,000-year-old artifacts in the Blombos Cave appear to show signs of pressure flaking, a process of finely shaping hard material. Before this, study author Paola Villa says, the oldest evidence of humans using the technique was dated to just 20,000 years ago.
Pressure flaking consists of trimming the edges of a finished tool by pressing with a bone point hard enough to remove thin slices of rock. This process creates the narrow, evenly spaced grooves found on flint tools from Europe’s 20,000-year-old Solutrean culture and prehistoric Native American groups. Wider, more irregular grooves characterize 36 pressure-flaked Blombos tools, which were made from silcrete, Villa says. This rock, a silica-rich material, is of lower quality than flint and requires heating to ready it for pressure flaking. [Science News]
It’s not easy to tell from these artifacts whether their makers simply hammered them into shape or used the more sophisticated flaking method to polish them off. So the team, led by Vincent Mourre, found silcrete around the cave site and tried to make their own.
In New Caledonia, an island off the eastern coast of Australia, a crow is hunting for beetle grubs. The larvae are hidden within a decaying tree trunk, which might seem like an impregnable fortress. But the New Caledonian crow is smarter than the average bird. It uses a stick to probe the tunnels where the grubs are sheltered. The grubs bite at intruders with powerful jaws but here, that defensive reflex seals their fate; when they latch onto the stick, the crow pulls them out.
This technique is not easy. Birds need a lot of practice to pull it off and even veterans can spend a lot of time fishing out a single grub. The insects are fat, juicy and nutritious but do they really warrant the energy spent on extracting them? The answer is a resounding yes.
Check out the rest of this post, including video of the crows at work, at Not Exactly Rocket Science. (The video above, of the birds making hooks, is from a different study a few years ago.)
And for plenty more about bird geniuses, be sure to read the DISCOVER feature “Who You Callin’ Bird Brain?” It includes more avian smarts, such as hiding food underground and going back later to move it, just in case other birds were watching the first time and thought about stealing a meal.
80beats: Not So Bird-Brained After All: Rooks Make and Use Tools
Not Exactly Rocket Science: Clever New Caledonian crows use one tool to acquire another
Not Exactly Rocket Science: Confirming Aesop – rooks use stones to raise the level of water in a pitcher
Was Lucy a tool user and a meat eater?
Quite possibly, argues a new study in Nature. Archaeologist Shannon McPherron turned up animal bones at an Ethiopian site that he says show markings of stone tool cutting dating back nearly 3.4 million years. That would be a big jump in the record: Right now the oldest known evidence of tool use among our ancestral species dates back about 2.6 million years.
McPherron’s date falls in the time of Australopithecus afarensis, the species to which the famous Lucy find belongs. But thus far he’s found only the markings on bones—not the tools themselves. Perhaps not surprisingly, though, at least one scientist behind the 2.6 million-year-old find says the new study is not convincing evidence that tool use dates back all the way to 3.4 million years ago.
For plenty more about the find—and the differing opinions—check out DISCOVER blogger Ed Yong’s post.
Not Exactly Rocket Science: Human Ancestors Carved Meat with Stone Tools Almost a Million Years Earlier Than Expected
80beats: Lucy’s New Relative, “Big Man,” May Push Back the Origin of Walking
DISCOVER: How Loyal Was Lucy?
Image: Dikika Research Project