The life expectancy of a bird depends on the species of bird. Environment also plays a role in the expected life span.
Smaller birds may not live as long as larger birds, partially because they are more at risk of getting harmed in the wild. They must watch out for predators and man-made hazards. Hunters, and the demolition of their homes also contribute to many birds having a decreased life expectancy. Seagulls can live up to 40 years. Parrots that are pets can live to be over 80 years old, since they have no major hazards.