"The results of the study are so broad that the scientific names of dozens of birds will have to be changed, and biology textbooks and birdwatchers' field guides will have to be revised," The Field Museum said Thursday in a release.

An international research team spent more than five years examining DNA from all major living groups of birds. The findings are published in the journal Science.

The study found that colorful hummingbirds evolved from drab nocturnal nightjars, falcons are not closely related to hawks and eagles and tropicbirds are not closely related to pelicans and other waterbirds.

"Our study and the remarkable new understanding of the evolutionary relationships of birds that it affords was possible only because of the technological advances of the last few years that have enabled us to sample larger portions of genomes," said Shannon Hackett, associate curator of birds at The Field Museum.