Ravens Think Abstractly About Possibility of Being Watched

Summary: Ravens think abstractly about the possibility of being watched as a display of Theory of Mind, according to a Feb. 2 study in Nature Communications.

Ravens display intelligence and social flexibility; a new study finds that out of sight is not out of mind, especially if the subject is a food cache: Ron Mead, CC BY 2.0, via Flickr

Ravens think abstractly about the possibility of being watched, displaying Theory of Mind, the perception-goal psychology of attributing mental states such as seeing to others, previously only confirmed in primates, according to a study published online Feb. 2, 2016, in Nature Communications.

The article’s three co-authors find that common ravens (Corvus corax) think beyond gaze cues to consider surveillance by other conspecifics (members of the same species) that are heard but are not visible.

“Here, we show that ravens Corvus corax take into account the visual access of others, even when they cannot see a conspecific. Specifically, we find that ravens guard their caches against discovery in response to the sounds of conspecifics when a peephole is open but not when it is closed,” state the three co-authors with affiliations with Austria’s University of Vienna and Texas’ University of Houston.

Four female and six male subadult ravens participate in the Theory of Mind experiment at the University of Vienna’s Haidlhof Research Station in northeastern Austria’s spa town of Bad Vöslau.

An experimental compound connects directly to the ravens’ keeping compartments. A transparent barrier of two wire mesh-covered windows in the compound divides the experiment’s two adjacent, identical rooms. Closing wooden panels creates an opaque, temporary barrier that visually closes each room from the other.

The study’s observed condition opens the wooden panels to allow complete visibility between the two rooms. The non-observed condition closes the wooden panels to prevent visibility. A cover opens and closes each panel’s peephole. A recording of sounds by a non-sibling competitor is played during non-observed conditions in which one of the two peepholes is open.

During baseline trials, a human experimenter familiarizes the 10 ravens individually with the two peepholes. The person calls the raven by name and displays a piece of cheese in the peephole. When the raven peers through the peephole, the person caches the cheese in the sand and then opens the rooms’ communicating door. The raven then reveals observance of the person’s caching by retrieving the cheese from the sand.

Of the 10 selected subjects, only one is excluded from further participation in the three test scenarios of the hypothesis that ravens think abstractly. Rufus displays fear of the peepholes.

The left room is set up as the caching room, where four pieces of cheese and dried dog food are provided. The right room, devoid of food, is designated for potential competitors.

The study’s ravens only know life in captivity. Their parents are captive breeding pairs in Austrian, German and Swedish zoos.

Taken to the research station as nestlings at about the age of 4 weeks, the 10 fledglings are accustomed to hand-raising by human caretakers for behavioral study purposes. They are trained to respond to their individual names and to participate in tests that isolate an individual physically and visually from the group.

The ravens’ socially-grouped keeping compartments at the Haidlhof Research Station are 5 meters (16.4 feet) high. Roofed areas provide sun- and weather-protection. Bathing tubs, perches, and artificial and live trees are included in the living compartments. Gravel, sand and wood chips serve as ground cover.

“Our results suggest that ravens can generalize from their own perceptual experience to infer the possibility of being seen. These findings confirm and unite previous work, providing strong evidence that ravens are more than mere behaviour-readers,” note co-authors Thomas Bugnyar, Stephan A. Reber and Cameron Buckner in their abstract to “Ravens Attribute Visual Access to Unseen Competitors.”

photo by Andy Clark/Reuters: RT @RT_com via Twitter Feb. 2, 2016

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

ravens: Ron Mead, CC BY 2.0, via Flickr @ https://www.flickr.com/photos/ronald-mead/2678807340/

photo by Andy Clark/Reuters: RT‏ @RT_com via Twitter Feb. 2, 2016, @ https://twitter.com/RT_com/status/694649438699151360

For further information:

Bugnyar, Thomas, et al. "Ravens attribute visual access to unseen competitors." Nature Communications, vol. 7: 10506. Published Feb. 2, 2016. DOI: 10.1038/ncomms10506.
Available @ http://www.nature.com/ncomms/2016/160202/ncomms10506/full/ncomms10506.html

Kever, Jeannie. "With Ravens, Out of Sight is Not Out of Mind." University of Houston > News & Events. Feb. 2, 2016.
Available @ http://www.uh.edu/news-events/stories/2016/February/0202RavenMind.php

NewsBeat Social. "New Study Finds Ravens Can Imagine Being Spied Upon." YouTube. Feb. 4, 2016
Available @ https://www.youtube.com/watch?v=Uu-Fa-EawE8

"Ravens capable of imagining being spied on - study." RT > News. Feb. 2, 2016. Edited Feb. 3, 2016.
Available @ https://www.rt.com/news/331084-ravens-intelligent-abstract-thinking/

RT‏ @RT_com. "Feeling paranoid? Ravens might just feel the same." Twitter. Feb. 2, 2016.
Available @ https://twitter.com/RT_com/status/694649438699151360