The State Of Bird Populations In U.S. 2009
This report covering bird populations in the United States shows that nearly a third of the country’s 800 bird species are endangered, threatened, or in significant decline due to habitat loss, invasive species, or other threats. This report documents a 40% decline in grassland birds over the past 40 years and a 30% decline in birds of arid lands. There has been a 39% of ocean-dependent species as well.
This report synthesizes data from three bird censuses conducted by scientists and biologists.
A particular area of concern is Hawaii, where more birds are in danger of extinction than anywhere else in the United States. More than one-third of all U.S. listed bird species exist in Hawaii and 71 species have gone extinct since humans have colonized the islands (300 A.D.)
At least 39% of ocean-dependent birds are in decline, facing threats from pollution, over-fishing, and warming sea temperatures caused by climate change. Some coastal shorebirds are increasing, but half of all coastal migrating shorebirds have declined due to human disturbance, dwindling food supplies, and sea level rises caused by climate change.
There is, however, an upward trend for wetland birds in the U.S. where the health of their habitats has been somewhat restored through waterfowl management.
Dramatic declines were noted in grassland and arid land birds, causing concern for neglect and degradation of these habitats. Incentives for wildlife compatible practices in these areas is needed to reverse these declines.
Forest birds have fared better than other birds, although many species have suffered decline due to unplanned and sprawling urban development, unsustainable logging, wildfires, and forest pests and diseases.