Crows complete basic 'Aesop's fable' task (w/ video)

March 26, 2014
Crows understand water displacement at the level of a small child. Credit: Sarah Jelbert

New Caledonian crows may understand how to displace water to receive a reward, with the causal understanding level of a 5-7 year-old child, according to results published March 26, 2014, in the open access journal PLOS ONE by Sarah Jelbert from University of Auckland and colleagues.

Understanding causal relationships between actions is a key feature of human cognition. However, the extent to which non-human animals are capable of understanding causal relationships is not well understood. Scientists used the Aesop's fable riddle— in which subjects drop stones into water to raise the water level and obtain an out-of reach-reward—to assess New Caledonian ' causal understanding of water displacement. These crows are known for their intelligence and innovation, as they are the only non-primate species able to make tools, such as prodding sticks and hooks. Six wild crows were tested after a brief training period for six experiments, during which the authors noted rapid learning (although not all the crows completed every experiment). The authors note that these tasks did not test insightful problem solving, but were directed at the birds' understanding of volume displacement.

Crows completed 4 of 6 water displacement tasks, including preferentially dropping stones into a water-filled tube instead of a sand-filled tube, dropping sinking objects rather than floating objects, using solid objects rather than hollow objects, and dropping objects into a tube with a high water level rather than a low one. However, they failed two more challenging tasks, one that required understanding of the width of the tube, and one that required understanding of counterintuitive cues for a U-shaped displacement task. According to the authors, results indicate crows may possess a sophisticated—but incomplete—understanding of the causal properties of volume displacement, rivalling that of 5-7 year old children.

This video is not supported by your browser at this time.
This video shows example trials for each of the six experiments. Credit: Sarah Jelbert

Sarah Jelbert added, "These results are striking as they highlight both the strengths and limits of the crows' understanding. In particular, the crows all failed a task which violated normal causal rules, but they could pass the other tasks, which suggests they were using some level of causal understanding when they were successful."

Explore further: Wild crows reveal tool skills

More information: Jelbert SA, Taylor AH, Cheke LG, Clayton NS, Gray RD (2014) Using the Aesop's Fable Paradigm to Investigate Causal Understanding of Water Displacement by New Caledonian Crows. PLoS ONE 9(3): e92895. DOI: 10.1371/journal.pone.0092895

Related Stories

Wild crows reveal tool skills

January 11, 2010

(PhysOrg.com) -- A new study using motion sensitive video cameras has revealed how New Caledonian crows use tools in the wild, Oxford University scientists report.

Crows show advanced learning abilities

December 14, 2011

New Caledonian crows have, in the past, distinguished themselves with their advanced tool using abilities. A team of researchers from the University of Auckland and the University of Cambridge have now shown these crows can ...

Crows do not plan their clever tricks

October 25, 2012

New Caledonian crows can spontaneously solve problems without planning their actions, a study published today in Proceedings of the Royal Society B reveals. 

Canny crows know their tools

October 8, 2013

(Phys.org) —Scientists at the University of St Andrews have discovered that New Caledonian crows, famous for their use of tools to extract hidden food, do not rely on guesswork when deploying one of their most complicated ...

Recommended for you

Secrets of a heat-loving microbe unlocked

September 4, 2015

Scientists studying how a heat-loving microbe transfers its DNA from one generation to the next say it could further our understanding of an extraordinary superbug.

Plants also suffer from stress

September 4, 2015

High salt in soil dramatically stresses plant biology and reduces the growth and yield of crops. Now researchers have found specific proteins that allow plants to grow better under salt stress, and may help breed future generations ...

Ancient walnut forests linked to languages, trade routes

September 4, 2015

If Persian walnut trees could talk, they might tell of the numerous traders who moved along the Silk Roads' thousands of miles over thousands of years, carrying among their valuable merchandise the seeds that would turn into ...

Huddling rats behave as a 'super-organism'

September 3, 2015

Rodents huddle together when it is cold, they separate when it is warm, and at moderate temperatures they cycle between the warm center and the cold edges of the group. In a new study published in PLOS Computational Biology, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.