majority of the area to be left undeveloped, and the protection provided by the Galapagos National Park. Most of the animal species in Galapagos are endemic, occurring nowhere else. But they are descendants of ancestors that colonized earlier, and then, isolated from their mainland origins, evolved into forms that are recognized as distinct today. Since 2001, many of the authors of this book have been part of a four-institution partnership investigating the threats posed by pathogens to Galapagos avifauna. They approach the topic of disease ecology in a novel manner, starting with the history of arrival of both the birds themselves and the pathogens. This synthetic approach requires the integration of themes from veterinary medicine, epidemiology, population genetics, and phylogenetics.