Crows have a reputation for being smart, but are they actually clever?
Fable and anecdotal evidence has persuaded us that crows and other members of the family Corvidae are among the smartest in the animal kingdom. But is this reputation deserved?
The infamous crow family – mischief-makers, messengers and omens of death; beautiful in sleek iridescence and magisterial in their swagger.
Their scientific name is Corvidae, and as well as crows they include ravens, rooks, jackdaws, jays, magpies, choughs, treepies and nutcrackers.
There are over 120 species and they’re astoundingly successful in habitats ranging from the Arctic to deserts, from coasts to the Himalayas, and from wilderness to inner cities.
The notion of corvid cleverness dates to Ancient Greece and has been embedded into our collective consciousness.
But only in the past 30 years or so has the science existed to support it. Today, there are dedicated corvid research centres around the world, and they are making fascinating insights.
New Caledonian crow, Corvus moneduloides
Quickly and flexibly solves tool-related problems, such as choosing tools of the right size for a task, making new tools, using tools in the correct sequence, and (as in Aesop’s fable) using objects to raise the water level.
Eurasian magpie, Pica pica
May recognise itself in the mirror, suggesting an awareness of ‘self’. It the only bird known to possibly be able to do this. Can also identify individual humans, and respond accordingly.
Common raven, Corvus corax
Adapts its cache-protection strategies, including tactical deception, to suit each situation.
Able, like domestic dogs, to follow the gaze of humans. Can also pull strings to retrieve food.
Western scrub jay, Aphelocoma californica
Has an episodic-like memory – it recalls what, when and where things are. Can plan for the future.
Like the common raven, it is also flexible in its cache-protection strategies.
Rook, Corvus frugilegus
Forms alliances and makes efforts to repair ‘friendships’ after conflicts.
Chooses appropriate tools and can fashion new ones. Uses objects to raise water level.
Eurasian jay, Garrulus glandarius
Plans ahead in relation to food caching. Shows awareness of its partner’s preferences when sharing food. Uses objects to raise water level.
Carrion crow, Corvus corone
Drops nuts under passing vehicles to crack them, and uses rocks or tarmac to smash molluscs. Distinguishes familiar and non-familiar human voices.
Western jackdaw, Coloeus monedula
Recognises human faces and follows human cues, for example tracking our gaze.
Dr Jo Wimpenny is a zoologist and writer, with a research background in animal behaviour and the history of science. She studied Zoology at the University of Bristol and went on to research crow problem-solving for her DPhil at Oxford University. After three years of postdoctoral research on the history of ornithology at Sheffield, she co-authored the book Ten Thousand Birds: Ornithology Since Darwin with Tim Birkhead and Bob Montgomerie, which went onto win the 2015 PROSE award for History of Science, Medicine and Technology. Jo writes for BBC Wildlife and has previously presented at the BA Festival of Science, Science Oxford, the Royal Society Summer Science Fair and Glasgow Science Fair.