Migratory birds play important ecological, economic, and cultural roles. Over half of bird species nesting in the US are neotropical migratory birds, including songbirds, waterfowl, birds of prey, and shorebirds, that migrate south to Mexico, Central/South America, and the Caribbean for winter. The legislative definition of migratory birds includes species that traverse parts of the US, Canada, Mexico, Russia, or Japan during annual migrations and need protection during nesting and migrations.