In _Stardust Memories_ of 1980, Woody Allen memorably called pigeons "rats with wings", summarizing how many urban dwellers think of them. Every city has pigeons, and this is just as much because of human nature as pigeon nature. In _Superdove: How the Pigeon Took Manhattan... and the World_ (Smithsonian Books), Courtney Humphries has presented a comprehensive look at this common bird (some would, of course, say common pest), but unlike a typical ornithological evaluation, this has to take in not just the natural history and evolution of the bird, but also the geography, history, and culture of the humans who have invited it to live in cities and indeed have shaped it to be able to do so. It's not the sort of bird you'd expect to see in, for instance, a special on the Nature Channel. "The pigeon is not the smartest bird, Humphries says, "nor the fastest, nor the prettiest, and it is certainly not the rarest. But it is capable of so much. More specialized birds might illustrate the limits of evolution, but pigeons show us its breadth." Pigeons show a widespread competence, rather than exploiting specialized expertise, and their interactions with us show a lot about human nature.
Pigeons are also called rock doves (and have recently been officially denominated "rock pigeons"), and indeed there is essentially no species difference between a dove and a pigeon. There are so many forms of pigeon because they were domesticated around five thousand years ago, probably the first domesticated birds. The birds were kept as a food source in dovecotes, and so began their long history of exploiting a niche in between full domestication and life in the wild. Pigeons also were used as messengers, and the capacity of pigeons to return to their homes has been the subject of biological investigation for decades; it seems that they can use sun position, smells, and visual cues, as well as being able to sense magnetic forces. The other way people use pigeons is for show. Careful breeding has developed birds that look vastly different from one another in color, posture, neck or tail feathers, and more. Pigeons were one of the many subjects Darwin pushed himself to find out about. Everyone knows that Darwin's finches from Galapagos are an important illustration of evolution, but not everyone realizes that pigeons played an even more important role. Darwin devoted the first chapter of the _Origin_ to pigeons because he saw that what human pigeon fanciers were doing with relative speed to their generations of pigeons, nature had done slowly with all animals and plants. It was a wonderful metaphor, easy to understand and vivid.
Humphries is a gifted writer, documenting with zest and humor her visits with world-wide experts on different aspects of this multifaceted bird, including ornithologists who are inspired by studying a bird that has changed so much through its long association with humans and other ornithologists who say such study is useless because the bird is so unnatural. She knows what to do about cities overpopulated with the birds, or at least she has talked to experts who have had success at reducing their cities' pigeon population. Every city is different, but, for instance, when Basel, Switzerland, realized that its pigeons were getting almost all their food from a small number of people who liked feeding them, it took action, not directly against the pigeons or against their feeders, but against the damage such feeders might do. "Feeding pigeons is animal cruelty," went out the message, enforcing the idea that unnatural feeding was swelling the population to unnatural limits. It worked; the pigeon population dropped from 24,000 to 8,000. _Superdove_ is also significant as a documentation of Humphries's own transformation from someone who took the birds for granted, but gradually found that they formed a huge world of history and research. It was generous of her to let us join her on the trip.