Birds are conspicuous, ubiquitous, and arguably the best studied group of vertebrates on the planet. Birds are also observed by millions of passionate birdwatchers worldwide. Birds engage in numerous and important ecosystem functions. Birds plant forests, devour pests, pollinate flowers, and scavenge carrion. Investigation of these ecosystem functions directly as ecosystem services has grown immensely over the last two decades. The services provided by birds are crucial to understand their importance for ecosystems and for the people that benefit from them. The chapters in this volume describe in detail many of the ecosystem services provided by birds. The examples throughout this book suggest that birds’ ecological roles, and, therefore, ecosystem services are critical to the health of many ecosystems and to human well-being. With understanding and valuing bird services we may assess the environmental consequences of bird declines and extinctions and communicate these findings to the public and policy makers. Thus we may support the conservation of birds and their habitats.