The Friedrich-Loeffler-Institut (FLI), which is responsible for animal health, has confirmed that it is the H5N1 subtype. It is the first confirmed case in Berlin this year. There was a similar case in December 2023. At that time, the virus was also discovered in a bean goose. The cold season is typically the peak season for bird flu. However, experts assume that the pathogen is now present in European wild bird populations all year round. At the end of 2022, the zoo had to close for weeks after avian influenza was detected in a waterfowl.