Tuesday, 18 September 2012

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


  1. Crows and I are open frenemies but secretly I love them like no other.

  2. I was coming out of ASDA with a packet of rolls,and was opening them because I was so hungry. As I left I looked up and saw crows surrounding the entrance and some on light posts and a shelter. I saw 2 empty trolleys and looked around to the crows and began tearing up parts of the rolls and throwing them into one trolley. Then there were a heap of struggling crows all frantically trying to get the roll bits but unable to because they could not get a stable footing on the mesh amidst the commotion. Then I noticed one crow going into the empty trolley, walking around a bit then flying out and into the trolley with the rolls in, the first successful crow to get a bit of roll.