Pessimism is infectious among ravens.
That's the conclusion of researchers who studied the birds in a bid to observe their intelligence and empathy, earlier this month.
Staff from the University of Vienna performed a cognitive bias test on the Gothic-looking animals, which monitored their reactions to neutral stimuli.
The findings show that, like humans and primates, they possess a level of emotional affinity and awareness.
Empathy: Staff from the University of Vienna performed a cognitive bias test on the Gothic-looking animals, which monitored their reactions to neutral stimuli
To test this, researchers denied one bird the promise of 'tasty' food.
When a second bird was introduced to watch this, they showed a suspicion of other offerings - and erred on the side of cynicism.
In other words, they shared empathy with other ravens and moderated their behaviour accordingly.
'To successfully and efficiently live in social groups, we need information about each other’s emotions,' the authors, Thomas Bugnyar and Jessie Adriaense, said.
'Emotional contagion has been suggested to facilitate such information transmission, yet it remains difficult to measure this in animals.
'Our findings suggest negative emotional contagion in ravens, and in turn advance our understanding of the evolution of empathy.'
The report was featured in The Proceedings of the National Academy of Sciences.
Did you know? Ravens overcome territorial pairs by living in gangs or flocks until they become adult and acquire an area for themselves.
WHAT ELSE CAN RAVENS DO?
Members of the corvid family, ravens are among the most intelligent bird.
A study from 2017 revealed that ravens even pre-plan tasks—a behavior long believed unique to humans and their relatives.
Ravens can also use tools, solve problems, mimic voices, spot themselves in a mirror and recognise human faces for many years after they have seen them.
Previously, ravens have been shown to have far higher stress levels when flocking together in adolescent gangs than when living in territorial pairs as adults.
In November 2018, researcher Johan Lind, associate professor in Ethology at Centre for Cultural Evolution, Stockholm University, analysed droppings and found increased levels of stress hormones among birds living in groups.
Ravens overcome territorial pairs by living in gangs or flocks until they become adult and acquire an area for themselves.
Scientists believe the maturing birds leave groups to form pairs as a direct result of stress.