Nearly 500 species of birds have been recorded in Oregon. Of these, there are approximately 275 species that regularly breed, and another 85 that regularly migrate through or winter. The remaining species comprise vagrants, only rarely found in the state. There are eight introduced species.
Numerous changes in Oregon's avifauna have occurred during the past century. Several species have experienced range expansions while many others have exhibited declining populations, often due to loss of habitat and other human-induced causes, making them increasingly vulnerable to extinction. The most well-known of these threatened species is the northern spotted owl. Please see the Oregon Birding Association web site for the Official Checklist of Oregon Birds.