There are at least eighteen bird species and bird sub-species listed on the endangered birds list that are native to North America. All of these birds are declining in population and will decline to the point where each and all of these categorized birds will become extinct.
Through the help and protection by federal, state, provincial and territory governments, by implementing laws and the creation of parklands and reserves, efforts are being put forward to prevent this from happening. These efforts include the studying of individual species, protecting the birds' habitats, removing the causes of the decline from what are determined as the apparent threats. This is all accomplished through the co-operation and dedication of the different governments, the conservation groups and the many volunteers, who together strive to understand these specific bird species that are declining. Such efforts can be witnessed today by the success of the California Condors and Whooping Cranes, where once again, these birds can be heard and seen again in our skies.
Included in the endangered birds list are the sub-species or races of birds. These birds are the sub-species Attwater's, Greater Prairie Chicken, the North Atlantic population of the Roseate Tern, the interior population of the Least Tern, the southwestern population of the Willow Flycatcher, the "Least" sub-species of Bell's Vireo, the Cape Sable sub-species of the Seaside Sparrow, the northwest species of the Northern Spotted Owl, the midwestern sub-species of the Piping Plover and the northeastern sub-species of the Loggerhead Shrike.
Avibase - the world bird database This site provides the user with a complete list of bird species, broken down per country, or in the example of the US or Canada, per state and province. Here, bird species names are available in other languages, a great asset to be used as a translation of foreign bird names.
ABA - American Birding Association This site represents an organization that maintains official records of all birds species that have been proven to have been seen inside the perimeters of the North American Continent and the surrounding bodies of water. Regular revised versions are posted to keep the bird list current at all times. This is the list used by all serious birders over their lifetime. You may be aware of the movie called the "Big Year". It was with this list that all the competing birders used in an attempt to set a new record as to how many bird species that could be seen by an individual birder in one calendar year.
I hope you will take advantage of these suggested websites. I have used each of them, in one way or another, throughout the years in my quest to better identify and understand our fine feathered friends.