After the first edition of Common Birds of Mexico City, the fieldwork of its creators continued; on the contrary, it multiplied and was enriched by the collaboration of other city residents interested in birds. This led to the observation and recording of several more species, which, due to their constant presence, we now consider "common." Likewise, the total list of species recently recorded in the city and its metropolitan area increased by almost 35%. Therefore, this second edition contains, among many other details: 159 images of Mexican birds with their respective data sheets. A list of 223 species, with their scientific and common names in Spanish and English. In addition, the latest changes dictated by the American Ornithologists' Union (AOU) were applied.