Birds amaze us every day, with their song and flying abilities. Adults and children have always been fascinated by flying. Birds in flight provoke envy and admiration, which is often described in songs, and they are often the subject of research. The new technology has made it possible for all ornithologists and other observers to track birds over long distances, to observe their behavior and appearance. The science that deals with the study of birds is ornithology. Ornithologists study birds by various methods, such as data collection, observation and monitornig in nature, and research in the laboratory, all for the purpose of protecting birds and so that we can admire these miraculous beings for as long as possible. In this paper, we will talk about the birds of the city of Zagreb, the richness of Zagreb flora and fauna, and our knowledge of children knowledge of the environment and sustainable development. At the beginning we will say something about the birds themselves, the ways in which they differ from the rest of the animal world, their characteristics, body structure and more. In the continuation of this paper, we will explain the differences and similarities between songbirds, migratory birds and nesting birds, and of course what species we can meet in the parks of the city of Zagreb. The city of Zagreb is rich in parks, which is way there is a name that says that Zagreb is a green city. One part of this paper will be dedicated to children, sustainable development and the environment, and in what ways we can unite these three concepts. The very end of the work will be marked by the project of setting up houses and bird food.