Non-breeding ravens live in highly dynamic social groups

March 23, 2017, University of Vienna
Ravens have impressive cognitive skills when interacting with conspecifics. Credit: University of Vienna

Ravens have impressive cognitive skills when interacting with conspecifics – comparable to many primates, whose social intelligence has been related to their life in groups. An international collaboration of researchers led by Thomas Bugnyar, Professor at the Department of Cognitive Biology, University of Vienna, could uncover for the first time the group dynamics of non-breeding ravens. The results help to understand the evolution of intelligence in this species and were published in the scientific journal Scientific Reports.

Several recent studies have revealed that ravens are among the most intelligent species of birds and even species in general. But which factors caused the evolution of intelligence? According to a common hypothesis life in social groups can drive especially when individuals benefit from remembering the identity of conspecifics and the interactions with them. With such knowledge, animals can avoid conflicts with higher ranking group members or develop alliances to gain better access to resources.

Researchers around Thomas Bugnyar in Austria and colleagues in France outfitted around 30 ravens with little "backpacks," which measured with GPS the position of the animal every hour. The devices were charged with solar power and the data were transmitted using the GSM network for mobile phones. During the last four years of data collection movements up to 160 kilometers per day were observed. In addition in Austria and Italy a total number of 332 ravens have been marked individually with colored rings and wing-tags and their presence patterns in two study sites were monitored over years.

Many ravens meet repeatedly in different locations usually at rich food sources. Credit: University of Vienna

Conclusion of the biologists: While some non-breeding ravens seem to stay only in relatively small areas, others may move thousands of kilometers per year. Still many ravens meet repeatedly in different locations usually at rich food sources (e.g. landfills, compost stations) and adjacent common night roosts. "We were surprised about the similarity to humans: Some people prefer to spend their entire life in a single city or even a small village, while others want to travel and explore the world. We find exactly the same in non-breeding ravens," says lead-author Matthias Loretto.

When ravens form groups they make friends but also fight heavily with other group members for access to resources. "Every time a joins a group of conspecifics at food sources, it can benefit from remembering previous interactions to decide who is friend or foe. The combination of social bonds within non-breeders and such a highly dynamic system might have driven brain evolution in ravens," says Loretto.

Raven with GPS, tracking the position of the animal every hour. Credit: Matthias Loretto

Explore further: 'Divide and rule'—raven politics

More information: Matthias-Claudio Loretto et al. Fission-fusion dynamics over large distances in raven non-breeders, Scientific Reports (2017). DOI: 10.1038/s41598-017-00404-4

Related Stories

'Divide and rule'—raven politics

October 31, 2014

Mythology has attributed many supernatural features to ravens. Studies on the cognitive abilities of ravens have indeed revealed that they are exceptionally intelligent. Ravens live in complex social groups and they can gain ...

Ravens cooperate—but not with just anyone

October 7, 2015

Ravens spontaneously solve a task that requires both coordination and cooperation—an ability that so far only a handful of species like chimpanzees and elephants have proved to master. A team of researchers led by Thomas ...

Ravens understand the relations among others

April 23, 2014

Like many social mammals, ravens form different types of social relationships – they may be friends, kin, or partners and they also form strict dominance relations. From a cognitive perspective, understanding one's own ...

Ravens learn best from their affiliates

July 13, 2016

One of the benefits of living together is gaining new information from group members. Once a group member starts displaying a new behavior, it frequently spreads to the rest of the group. In a study on ravens, Cognitive Biologists ...

Ravens remember relationships they had with others

April 19, 2012

In daily life we remember faces and voices of several known individuals. Similarly, mammals have been shown to remember calls and faces of known individuals after a number of years. Markus Boeckle and Thomas Bugnyar from ...

Recommended for you

World's last male northern white rhino, Sudan, dies

March 20, 2018

The world's last male northern white rhino, Sudan, has died after "age-related complications," researchers announced Tuesday, saying he "stole the heart of many with his dignity and strength."

Why aren't humans 'knuckle-walkers?'

March 20, 2018

Our closest biological relatives, the African apes, are the only animals that walk on their knuckles; CWRU researchers discovered why


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.