In a piece for the BBC, Chris Baraniuk writes about how the intelligence of New Caledonian crows may be far more advanced than we ever thought possible. An anonymous reader shares an excerpt from the report: Intelligence is rooted in the brain. Clever primates -- including humans -- have a particular structure in their brains called the neocortex. It is thought that this helps to make advanced cognition possible. Corvids, notably, do not have this structure. [New Caledonian crows belong to the corvid family of birds -- as do jackdaws, rooks, jays, magpies and ravens.] They have instead evolved densely packed clusters of neurons that afford them similar mental prowess. The specific kind of brain they have doesn't really matter -- corvids and primates share some of the same basic capabilities in terms of problem-solving and plasticity, or being able to adapt and change in the face of new information and experiences. This is an example of convergent evolution, where completely different evolutionary histories have led to the same feature or behavior. It's easy for humans to see why the things corvids can do are useful. From identifying people who have previously posed a threat to them or others in their group to using gestures for communication -- we too rely on abilities like these.

[Christian Rutz at the University of St Andrews] is unequivocal. Some birds, like the New Caledonian crows he studies -- can do remarkable things. In a paper published earlier this year, he and his co-authors described how New Caledonians seek out a specific type of plant stem from which to make their hooked tools. Experiments showed that crows found the stems they desired even when they had been disguised with leaves from a different plant species. This suggested that the birds were selecting a kind of material for their tools that they knew was just right for the job. You wouldn't use a spanner to hammer in a nail, would you? Ranking the intelligence of animals seems an increasingly pointless exercise when one considers the really important thing: how well that animal is adapted to its niche. In the wild, New Caledonians use their tools to scoop insects out of holes, for example in tree trunks. Footage of this behavior has been caught on camera.

You might think that some animals are smarter than others -- with humans at the top of the proverbial tree. Certainly, humans do rely excessively on intelligence to get by. But that doesn't mean we're the best at every mental task. Chimps, notes Dakota McCoy at Harvard University, have been shown to possess better short-term memories than humans. This might help them to memorize where food is located in the forest canopy, for example. Ranking the intelligence of animals seems an increasingly pointless exercise when one considers the really important thing: how well that animal is adapted to its niche. Intelligence is, first and foremost, a means towards specialization. "New Caledonian crows, like us and other clever animals, have moods and memories. Strategies and expectations. They seem remarkably able to engage with complexity," writes Baraniuk in closing. "Evolution made this possible. But cognition, like life itself, serves more than just a need. Animal intelligence allows all sorts of fascinating phenomena to arise. [...] Nature provided the notes, but animal brains make the music. The mind, as they say, is the only limit."