Crows are smart. Anyone who watches them for a while can figure this out.
But that is true of a lot of things. Your baby is smart (not really). Your dog is smart (not really). Ants are smart (sort of).
It takes a certain degree of objective research, as well as some serious philosophy of intelligence (to define what smart is) to really address this question. But when the research is done and the dust settles, crows are smart.
We were all amazed (or not, because we already knew that crows are smart) to find that New Caledonian crows made and used tools. Now, we know (see my most recent post at 10,000 Birds) that a nearly extinct Hawaiian crow is also a tool user. The interesting thing about this new finding is that it is highly unlikely that the Hawaiian crow and the New Caledonian crow descend from a tool using ancestor, according to the researchers who did this work. Rather, tool use arose independently in the two species. But, really, not so independently.
They are all crows, and crows are smart, and both of these species live in a particular habitat where this tool use makes sense, and competing species of bird that might otherwise be going after the resources the tool use allows access to are absent. So, the trait evolved twice, but not unexpectedly.
The Evolution and Development of Bird Intelligence
I want to point out two things about birds that you probably know. First, they share modalities with humans to a greater degree than most other species, even our fellow mammals. Second, many birds live under conditions where complex behavior would be selected for by long term Darwinian processes.
Most mammals are solitary, small and nocturnal, or if large, are diurnal herd animals or some sort of predator. They tend to be olfactory and have varying degrees of vision, etc. We, on the other hand, are highly visual, not very olfactory, diurnal, and have a complex social system, and so on. We share these traits, for the most part, with our fellow primates, but humans live in many non-primate habitats these days, so we tend to stand out as a bit odd. If you are reading this blog post, chances are that the nearest non-pet and non-human mammal that you could locate right now is a squirrel, and the actual nearest mammal is some sort of rodent that you would have a hard time finding.
But, the nearest animal with an interesting brain, and interesting behavior, is a bird. Go look out your window and report back. I'll study this diagram on the evolution of intelligence while I await your return.
The visual orientation, together with that second trait of smartness, combine to make birds and their smartness akin to human's smartness to the degree that we subjectively see birds as "intelligent," and that alone is interesting. But likely, we are both intelligent by objective criteria, about certain things.
Bird Brain: An Exploration of Avian Intelligence was written by Nathan Emery, who is a Senior Lecturer (that's like a Professor of some sort, in America) at Queen Mary University, London. He researches the evolution of intelligence in animals, including primates and various birds, and yes, including the crows!
He and his team "...have found striking similarities in the behaviour, ecology, neurobiology and cognitive mechanisms of corvids (crows, rooks, jackdaws and jays) and apes. [Suggesting that] these similarities are adaptations for solving similar social and ecological problems, such as finding, protecting and extracting food and living in a complex social world."
The book is really great, the best book out there right now on animal intelligence, possibly the best book so far this year on birds. This is the kind of book you want laying around the house or classroom to learn stuff from. If you are writing or teaching about anything in evolution or behavior, this is a great way to key into the current work on bird intelligence.
Bird Brain is also going to earn a place on my Holiday Shopping Guide in the "Best gifts to give a science oriented youngster or your local life science teacher to encourage thinking about evolution" category. Yes, this is definitely a gift level book. Nobody will not like this book.
This is like a coffee table book in that it is slightly larger (not huge, just a little big) format, and full of great pictures, and the kind of book you can pick up and start reading anywhere. But it is also a book with a story, in a sense, or at least, an arc organizing the research being reported on. It is engagingly and well written and, very importantly, written by an expert.
I do respect journalists who become very interested in a topic and learn all about it and write it up, but there are limitations to such work. It is possible for various errors, minor or not, to sneak into such a work because the author is not deeply engaged in the way that a lifelong commitment to a work allows for. Bird Brain is written by an expert, so that is not going to happen here.
I highly recommend Bird Brain, for anyone who does not want to be a bird brain about birds, intelligence, evolution, or the evolution of intelligence in birds.
Here's the TOC:
Well it's dark here (UK) so I can't see anything outside. I can hear the owl that goes keWICK - I'm not a bird watcher so I don't know which one of our owls that is. Mammal is of course most likely a rat, though possibly a badger as one does come through most nights.
If it was daytime most likely birds would be pigeons, magpies or crows at first glance though we do get a lot of smaller birds too. And yes mammal would be squirrel.