1. The aggregate of bird species found in a particular region, habitat, or geological period
The bird fauna of the Amazon rainforest is incredibly diverse.
A avifauna da floresta amazônica é incrivelmente diversa.
2. The study or documentation of bird species characteristic of a specific area or time
Researchers catalogued the bird fauna of the newly discovered island.
Pesquisadores catalogaram a avifauna da ilha recém-descoberta.