Although a wide variety of bird species have been shown to contract and spread Influenza A virus subtype H5N1, from waterfowl to poultry and birds of prey, mammalian infections have been of particular interest to researchers due to their potential to develop mutations that increase the risk of mammal-to-mammal spread and transmission to and among humans.
Other influenza strains are common among mammals, including humans, but this list only shows those who have been proven to carry H5N1. In October 2022, farmed mink became the first detected mammal able to engage in mammal-to-mammal spread of H5N1.