More than 800 species of birds inhabit the United States, in places as diverse as Hawaii, Alaska, Florida, and everything in between. Among these species, there are 67 federally endangered or threatened birds and 184 birds of conservation concern. This listing could be due to declining population numbers, small distributions, and/or high threats.
To help shed some light on the state of our country's birds, a variety of organizations (including but not limited to The Audubon Society, The Nature Conservancy, The American Bird Conservancy, The Cornell Lab of Ornithology, US Fish & Wildlife Service, USGS, and others) have compiled statistics spanning 40 years. In this comprehensive report, The State of the Birds looks at the past trends and current situations of bird populations that reside in each of the major habitat types.
The report expresses a specific concern on Hawaiian bird populations, noting that 71 species have gone extinct since humans colonized the islands and at least 10 more species have not been seen in as long as 40 years (draw your own conclusions here, but that sounds like 81 extinct species to me). Many surviving populations are on the verge of extinction and without swift conservation measures these birds may be headed for the history books.
Check out the full report at http://www.stateofthebirds.org/ - some of the numbers will shock you, but there is also a ray of hope. There have been successful management strategies for a number of species. The Bald Eagle, the Peregrine Falcon, and the Osprey have all rebounded from the brink. Other species including certain waterfowl populations have increased thanks to focused conservation measures. There is still a chance for the other imperiled birds, but that chance becomes smaller and smaller the longer people wait to act.