Drinking Game Adds to Growing Support for Chimpanzee Culture

(LATimes, 30, January 2012) - Do chimpanzees have culture? It may depend on your definition of that slippery concept, but a new study using juice and soft straws shows that chimpanzees fill a basic requirement: They can learn new behaviours from one another.

Journal article: Basis for Cumulative Cultural Evolution inChimpanzees: Social Learning of a More Efficient Tool-Use Technique

Many researchers argue that few species, and perhaps none besides our own, have the capacity for culture – learned behaviours to spread across a population and down through future generations. (For humans, the definition would include things like beliefs, aesthetics, moral codes and knowledge, but given that chimpanzees lack language and can’t be asked about subjective thoughts, observable behaviours will have to do.)

Previous research had shown that wild chimps in separate communities would use sticks in different ways to fish for ants, a sign that such behaviours went beyond instinct. The new paper, published online Wednesday in the journal PLoS ONE, actually catches captive chimps in the act of learning such different tool uses.

The study presents "the first experimental evidence for chimpanzees' social transmission of a more efficient tool-use technique invented by a conspecific group member," according to the authors.

Researchers from Kyoto University in Japan and the University of Kent in England gave two groups of chimpanzees straws and put them in rooms with juice boxes mounted onto the wall. One group started using the 7-inch straws to dip into a hole in the juice box, while the other started using the sucking method (as humans would for a milkshake, or pretty much any other drink). 

Sucking juice through a straw was 50 times more efficient: A chimp could down 50 milliliters of juice in 30 seconds, while it would take their dipping peers 10 minutes to pull out a mere 20 milliliters.

When the researchers put a straw-sucker and a straw-dipper in the same room, they found that the dipper would quickly adopt this better, faster method if they closely observed it in action.

The demonstrating chimps didn’t seem to mind this up-close-and-personal style of learning. One video of the experiment shows a curious chimpanzee putting his face right up in the face of another chimp who was sucking the juice through a straw, then grabbing a straw of his own to try out this new, better method.

"Chimpanzees switch technique when not satisfied with their own," the study authors write. "Hence, necessity and opportunity appear to act as key prerequisites for cumulative cultural evolution."

Crows can 'reason' about causes, a recent study finds

Curious crow is curious

(BBC Nature, 18, Sept, 2012) - Tool-making crows have the ability to "reason", say scientists.

In an experiment, researchers found that crows were more likely to forage when they could attribute changes in their environment to a human presence.

This behaviour may suggest "complex cognition", according to a study published in the Proceedings of the National Academy of Sciences.  Until now the ability to make inferences based on causes has been attributed to humans but not animals.

The study was a collaboration between researchers from the University of Auckland, New Zealand, the University of Cambridge, UK and the University of Vienna, Austria.

In their experiment eight wild crows used tools to remove food from a box.  Inside the enclosure there was a stick and the crows were tested in two separate series of events that both involved the stick moving.

In one instance a human entered the hide and the stick moved. In the other, the stick still moved but no human entered.  On the occasions when no human was observed entering the hide, the crows abandoned their efforts to probe for food using a tool more frequently than they did when a human had been observed.

According to the scientists, the study proved that crows attributed the stick's movement to human presence.

The results indicated that neither age nor sex was a predictor of the behaviour with juveniles, males and females displaying the same behaviour.  Scientists said that the kind of "reasoned inference" shown by the New Caledonian crows under these controlled conditions could also be utilised in the wild to anticipate danger or food.

The study is the first to suggest that animals have the ability to make reasoned inferences, although scientists added that the phenomenon could be more common among animals than previously thought.

Journal reference: New Caledonian crows reason about hidden causal agents - http://www.pnas.org/content/early/2012/09/10/1208724109