Birds of Portugal: An Annotated Checklist has been written with two objectives in mind. Firstly, to provide an update to the existing species lists and secondly, to make this information available in a practical and accessible format that can be easily understood and used by anyone with an interest in birds, including those that belong to the non-specialized public. This list is an update of the previous edition, which was published in 2013. The contents have been totally reviewed. Additionally, several species, which have been recorded for the first time during the last four years, have been added to the list. Several texts were also updated, in order to provide information about recent sightings.