Why wild birds are carrier for bird flu and are not affected?

Wild birds, particularly waterfowl, can carry the avian influenza virus without showing symptoms because they have developed a level of immunity to it. They serve as natural reservoirs for the virus, allowing it to persist in the environment. In contrast, domestic birds can be more susceptible to severe illness when exposed to the virus, which is why monitoring wild bird populations is crucial for understanding and managing the risk of outbreaks in domestic poultry.