http://www.digitaljournal.com/news/environment/half-of-usa-bird-species-under-threat/article/403018

Half of U.S. bird species under threat

Posted Sep 13, 2014 by Tim Sandle
A report from the National Audubon Society suggests that more than half of U.S. bird species are under threat. The reasons given range from displacement to extinction due to climate change.
Barred Owlet-nightjar (Aegotheles bennettii)
Barred Owlet-nightjar (Aegotheles bennettii)
markaharper1
According to the report, by the end of this century, more than 300 bird species in the U.S. could be extinct. Furthermore, some thirty species, including the northern gannet, the trumpeter swan, the rufous hummingbird, and the northern hawk owl, may be squeezed from 90 percent of their current territory.
Discussing the somewhat alarming finding, David Yarnold, the president of the National Audubon Society, told The New York Times: "Common sense will tell you that with these kinds of findings, it’s hard to believe we won’t lose some species to extinction. How many? We honestly don’t know. We don’t know which ones are going to prove heroically resilient."
This is not the only recent report to draw similar conclusions. A consortium of government agencies, researchers, and conservation organizations reiterated those findings in a separate study titled "The State of the Birds Report 2014".
This report emphasizes:
After examining the population trends of birds in desert, sagebrush and chaparral habitats of the West, the report’s authors identify aridlands as the habitat with the steepest population declines in the nation. There has been a 46 percent loss of these birds since 1968 in states such as Utah, Arizona and New Mexico. Habitat loss and fragmentation due to development are the largest threats. These are also significant threats in the nation’s grasslands, where the report notes a decline in breeding birds, like the eastern meadowlark and the bobolink, of nearly 40 percent since 1968. That decline, however, has leveled off since 1990—a result of the significant investments in grassland bird conservation.
Commenting on the second study, Mark Eaton, a conservation scientist for the Royal Society for the Protection of Birds in Sandy, U.K., told Science: "More conservation is needed, particularly to avoid extinctions in Hawaii and other islands."