Avian influenza is a severe form of bird flu. Avian (Latin avis – bird) means that birds are primarily affected by the disease. Among wild birds, waterfowl often transmit the disease and cause high losses when it is transmitted to domestic poultry stocks.

The highly contagious bird flu is currently spreading rapidly and has been detected in neighboring districts and Mainz. In a press release dated November 4, 2025, the veterinary office issued a general order requiring poultry farmers in the Mainz-Bingen district and the city of Mainz to keep their animals in barns to protect them from bird flu. This applies to both professional farms and hobby farmers. In addition, poultry markets and exhibitions are prohibited.

For this reason, increased safety measures are currently in place at Mainz Zoo to protect the animals. The aviary in the city park will remain closed to the public during the period of mandatory confinement due to the regulations. The animals are currently housed in the indoor aviaries. At Gonsenheim Wildlife Park, the chicken coops have been secured accordingly, the geese are being housed in a large tent in a manner appropriate to their species, and no more birds of prey are being taken in to protect the park's own stock.

It is recommended that obviously sick seagulls, ducks, geese, swans, or birds of prey not be collected and taken to veterinary practices or animal shelters. Likewise, none of these dead birds should be collected from public spaces. If a dead migratory or water bird is discovered, this find should be reported immediately to the veterinary office.