Why would a famous virologist and immunologist (and Nobel laureate) write a book linking birds, human diseases, and ecological degradation? The answer is partly that Peter Doherty obviously has a soft spot for birds and birdwatching. He argues that anyone with an enquiring mind and a natural history bent cannot fail to notice birds and to be intrigued by them. But the full answer is that Doherty is perfectly placed to contemplate such seemingly arcane questions because his professional life, spent deep in the intricacies of the immune system and the control of infectious diseases, has allowed him to grasp the fundamental role that birds play in research into infectious diseases, particularly influenza, in the transmission of viral diseases, and also in research into malaria and cancer. He also demonstrates a clear understanding of ecological principles and the complexities of the major conservation issues that we face. Combine this with an ability to write clearly and succinctly about complex subject matter, sprinkled with fascinating personal anecdotes, and you have a quirky and satisfying book.