I am now reading this book too. I agree with "lintworm"; it is an extremely interesting book, essential reading for anybody interested in the taxonomy of birds. It's a beautifully illustrated volume too.I have now almost finished The largest avian radiation by Jon Fjeldsa, Les Christidis and Per Ericson.That really is a fascinating read for anyone with an interest in taxonomy, biogeography, birds or all combined. It is almost out of stock, but I would highly recommend it. It is not easy writing, but well worth it and apparently almost sold out...