Birds are some of the most ubiquitous animals on Earth, inhabiting a diverse range of ecosystems. They are also well-known reservoirs of viruses, such as the highly pathogenic avian influenza virus that has caused major epidemics in humans and domesticated animals worldwide. However, most research has mainly focused on viruses associated with poultry, leaving the broader natural viral diversity across most bird species largely unexplored. In this project, I aim to address this gap by identifying and characterizing viruses across a wide range of bird species. To do this, I will leverage the public databases of next-generation sequencing data, which contains DNA and RNA sequences from hundreds of bird species. Since viruses integrate or introduce their genetic material into host cells during infection, they can be detected within these datasets without the need for additional sampling. By utilizing this unprecedented amount of open-access sequencing data, we can construct a comprehensive overview of viral diversity across the avian tree of life. This will enable us to explore how viruses shape global avian distributions, uncover host–virus evolutionary relationships, and understand transmission dynamics that can guide risk assessment and surveillance strategies for potential viral outbreaks.