[Ed. – No mention of the estimated 140,000 to 328,000 birds that die each year in North America from crashing into wind turbines.]
The number of birds in the United States and Canada has fallen by 29 percent since 1970, scientists reported on Thursday. There are 2.9 billion fewer birds taking wing now than there were 50 years ago.
The analysis, published in the journal Science, is the most exhaustive and ambitious attempt yet to learn what is happening to avian populations. The results have shocked researchers and conservation organizations.
In a statement on Thursday, David Yarnold, president and chief executive of the National Audubon Society, called the findings “a full-blown crisis.”
Experts have long known that some bird species have become vulnerable to extinction. But the new study, based on a broad survey of more than 500 species, reveals steep losses even among such traditionally abundant birds as robins and sparrows.
There are likely many causes, the most important of which include habitat loss and wider use of pesticides.