Animals making tools...what else are they capable of?

A pair of rooks. Photo by Christopher Bird, news.bbc.co.uk

Animals are at it again. Acting human. Or rather, exhibiting behaviors that we once thought were exclusively human. We once believed, I might say, that these behaviors defined humans as better, different, smarter than all other living things.

I'm talking about tool use. As it turns out, tool use has now been observed in dozens of nonhuman species, including otters, monkeys, chimps, and 39 species of birds!

The most recent study involves rooks, a crow-like European species common in folklore. They're in the same family as our American crows, ravens, jays, and magpies.

The rooks in this study, reported just today (May 28) in the Proceedings of the National Academy of Sciences, were given access to food that could only be obtained by pushing a small rock off of a ledge into a tube. They quickly mastered that task. Christopher Bird of the University of Cambridge and Nathan Emery of Queen Mary College, London, challenged the birds further by moving the small rock farther away. Before long, a female rook, Fry, figured out picking up the stone and carrying it to the ledge. Her mate, Cook, followed her actions, then a second pair did.

The birds mastered various other tasks involving tools such as sticks and wires. They even figured out how to bend a wire to fashion a hook necessary to retrieve items. Although wild New Caledonian crows have been observed fashioning hooks in the past, the authors assert that this is the "first unambiguous evidence of animal insight, because the rooks made a hook tool on their first trial we know that they had no previous experience of making hook tools from wire because the birds were all hand-raised." The New Caledonian crows were known to use tools in the wild.

I love research that shows how smart animals are, and how we're not the supreme beings we think we are. What else are animals capable of that we don't know about yet? They deserve more respect, more of the world's remaining resources, than they're getting from their human relatives.

My previous post about New Caladonian crows making tools.

All my previous posts about tool use (or making tools) in animals.

Sources:
Christopher D. Bird and Nathan J. Emery. Insightful problem solving and creative tool modification by captive nontool-using rooks. May 28, 2009. Proceedings of the National Academy of Sciences.

Randolph E. Schmidt, Associated Press. Rooks figure out how to use tools. May 28, 2009. Charlotte Observer

Key words:: birds tool use rooks animal behavior making tools bird behavior animal intelligence

Wild monkeys use tools - and choose the right one for the job

The first monkeys I ever saw in the wild were white-faced capuchins in Costa Rica. Or maybe black howlers were first. But the capuchins were much more charming than the howlers. I fell in love with them. We were on the beach at Manuel Antonio Parque Nacional the first time, and my son Alan had a banana in his pocket. The capuchins were interested in us because of the banana, and they had no fear. The howlers and spider monkeys and squirrel monkeys will stay up in the trees, far away from you, no matter what you have or do. But the capuchins come right down. They even ran out on the beach and snatched things from people's picnic baskets. The capuchins, with their human-like faces and hands, sat in the trees eating bags of crackers and throwing the cellophane wrappers down.

A white-faced capuchin at Manuel Antonio Parque Nacional in Costa Rica, smelling the banana in Alan's pocket
Photo by Sally Kneidel

As a biologist, I know that's not a good thing at all. But yet, I could see myself in the capuchins. I also do what I'm not supposed to do, eat things I know aren't good for me, make choices that endanger my well-being. We were tempted to give the capuchins the banana, but we didn't. We didn't give them anything to eat, we knew better than that. Monkeys that eat human food get sick eventually from malnutrition.

But the next day, we asked the ranger what time the troop of capuchins usually moved through the trees over the beach, on their daily foraging rounds. Our Spanish communication wasn't precise, but he told us and we got the idea. We waited for the monkeys. They came. And they were mad that Alan and I were standing under the trees while they were cavorting from branch to branch, just overhead. The head honcho, a male capuchin, came down and bared his teeth at us and shook the branches to frighten us. We trembled with delight instead.... the pleasure of recalling it even now makes my heart beat fast. We took his photo while he railed at us, infuriated. I was sorry to distress him, but I couldn't help it. Monkeys are territorial, they get angry just like anyone whose space is invaded. It wouldn't hurt him to bare his teeth and shake a few branches. His social stature with his troop may have benefitted from the display.

The capuchin was angry that we were standing under the trees in his foraging route. He bared his teeth aggressively.
Photo by Sally Kneidel

Anyway, I started this post to write about a news story that just came out about capuchins. Capuchins used to be "organ grinder" monkeys. These days they're sometimes trained as "helping hand" monkeys for people with paraplegia or quadriplegia. They're very smart monkeys. This recent piece of research shows that capuchins in Brazil are adept at tool use - an ability that used to be attributed only to humans but has now been demonstrated by numerous species from birds to apes. The capuchins use stones to crack open hard-shelled nuts. But the research goes far beyond just demonstrating tool use. The capuchins don't just grab the nearest rock at hand. They select the best tool for the job. Primatologist Elisabetta Visalberghi of the Institute of Cognitive Sciences and Technologies in Rome has shown that these monkeys draw on knowledge of a variety of nuts and stones to select the most effective implement. She studied the monkeys in the wild and observed that they generally approached two or three stones that differed in hardness, size, or weight. In nearly every case, the monkeys chose the most appropriate stone.

"The present findings make capuchins a compelling model to track the evolutionary roots of stone-tool use," says Visalberghi. Because capuchins shared a common ancestor with humans 35 million years ago, Visalberghi feels that their behavior may demonstrate that the capacity for tool use evoloved earlier than thought.

But primatologist Frans de Waal of Emory University has a different interpretation. He says the work highlights the monkeys' capacity for trial-and-error learning, that planning may not have been a part of their tool preferences. The monkeys may be simply applying life lessons about the success of various stones at cracking nuts.

Capuchins in Brazil selecting stones for cracking nuts, from Wired Science

Whether their discriminatory skills are the result of planning or of learning, they're still a step beyond simple tool use. They demonstrate in a non-human animal the ability to select and apply an appropriate tool for a particular job. We humans are not so unique after all. Do we really deserve to claim the whole planet all for ourselves and crowd out every other species of animal, leaving only the pest species, the livestock, and the companion species? I hope not. I hope the capuchins will always be alive and well in Costa Rica and Brazil, not displaced by cattle pastures.

Source:
Bruce Bower. Monkeys pick the right rock. Science News. February 14, 2009.

Keywords:: capuchins tool use animal behavior monkeys Costa Rica

Dolphins learn tool use from their moms

Dolphin with sponge to protect sensitive snoot while foraging

Not too long ago, scientists used to believe that "tool use" was one of the characteristics that set humans apart from all other animals.

We now know that animals do use tools. The list of species observed not only using tools, but making tools, continues to grow.

Chimpanzees were the first species observed with tools - Jane Goodall saw chimps using sticks to extract edible termites from underground tunnels. More recently, chimps have been observed making and using spears on other prey.

Bird species also make tools to forage. A warbler species on the Galapagos uses thorns to probe under bark, and scrub jays make and use hooks to retrieve edible items - to name a couple of examples.

Marine biologists have also documented bottlenose dolphins using tools. Scientists say that dolphins in Australia's Shark Bay wear marine sponges on their beaks like a glove, to protect their sensitive beaks when foraging along rugged ocean bottoms. Poking around in deep water carries the risk of stings from bottom dwellers.

(Sponges are animals on the ocean floor whose skeletons are flexible and absorbent.)

The boater who first saw a sponge on a dolphin thought it was a tumor. But the tumor turned out to be a sponge.

As marine biologists have studied the tool use, they've discovered something even more interesting. Only the dolphins in the Shark Bay location use the sponges, and only a fraction of the dolphins in that bay use them. The scientists have studied the family relationships of the dolphins in the bay and have now determined that the spongers belong almost exclusively to a single maternal lineage. The sponge behavior is being transmitted from mothers to offspring.

But... the sponging doesn't follow any of the patterns that would be expected if it were genetically based.

The scientists have concluded that the spongers are learning the behavior from their mothers - the only interpretation that fits the observed family relationships of the spongers. Whether the spongers are learning from observing their mothers, or are being intentionally instructed by their mother remains to be seen.

This is not the first example of what is known as "cultural transmission" of behaviors in animals - behaviors transmitted to other individuals by way of observation or instruction. At least one population of macaque monkeys regularly wash their grains in pools of water, and that behavior is known to be culturally transmitted, for these particular monkeys.

Macaque washing food
photo courtesy of www.animalplanet.com.au

What more will we learn in future years about the traits we share with our animal relatives?

These discoveries are, for me, all the more reason to do whatever we can to stop the environmental degradation that threatens wildlife species worldwide.

See my previous post for three things you can do to slow habitat loss from global warming.

Source:
Susan Milius. "Sponge moms: dolphins learn tool use from their mothers." Science News, June 11, 2005

Keywords :: bottlenose dolphins marine biology tool use cultural inheritance cultural transmission animal intelligence animal behavior macaques