The idea that people are like birds is far from new. In the first century AD, the Roman scholar Pliny the Elder defined man as ‘the featherless biped’, only to have the cynical philosopher Diogenes march into a lecture theatre clutching a plucked chicken shouting: ‘Here is Plato’s man!’ In a more light-hearted vein, many of the cartoons and limericks of the nineteenth-century artist and writer Edward Lear were based on the apparent similarities between birds and ourselves.
Research undertaken in the last two decades has shown that the cognitive abilities of certain groups of birds are at least as well developed as they are in certain primates, including ourselves. ‘Intelligence’ is notoriously difficult to define, but here it means ‘the ability to invent a new solution to a problem – a solution that does not rely on built-in solutions that evolution has provided’. The cognitive celebrities – the avian clever clogs, and the ones Martinho-Truswell says are most like us – are (of course) the parrots and corvids, with their well-known problem-solving abilities and their ability to mimic the human voice.
Martinho-Truswell is a research biologist who studies learning and cognition. His main idea in this book is that birds (or at least certain ones) and people, having been subject to the same evolutionary selection pressures, have evolved along similar lines characterised by long life, social monogamy, a protracted period of dependency and, in some cases, ‘intelligence’.
This is a charming and sometimes challenging account. It did make me wonder whether by focusing on avian celebrities, a disservice has been done to the rest of the avian world. It is a bit like thinking that the whole of humanity is epitomised by the finalists on University Challenge. We consider parrots and corvids as clever because we think what they do is clever; but, as Martinho-Truswell acknowledges, other birds do lots of things, and seem to survive equally well in similar or even greater numbers, but we do not immediately recognise what they do as ‘clever’. Few of us would think of the Woodcock Scolopax rusticola as ‘clever’ – but a colleague of mine who hand-reared one taught it to do a range of impressive tricks.
Engagingly and entertainingly written, this book places some of the many recent discoveries about bird intelligence into a fascinating human–bird framework.