Climate change also appears to be altering migration patterns of many species of birds, but with differential effects. Some long distance migrant birds show earlier spring migration, whereas others do not. Climate-associated changes in the distribution, composition, and migratory behavior of wild bird hosts may cause important changes in avian influenza epidemiology. However, geographically-specific directional predictions will require a knowledge of the behavioral (e.g. contact) patterns of species.
There may be an indirect effect, as climate change, which leads to delayed migration in some areas, leads to increased contact with poultry in these areas, and thus there is prior contact between poultry and livestock in these areas through several methods (such as transportation in the same cars or contact between breeders).