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North America has lost nearly three billion birds since 1970, a new study says, which also found significant population declines among hundreds of bird species, including those once considered plentiful. USA TODAY

About two-thirds of America’s birds will be threatened with extinction if global warming tops 5.4 degrees by 2100, according to a report released Thursday from the National Audubon Society, a bird-focused conservation group.

“A lot of people paid attention to last month’s report that North America has lost nearly a third of its birds,” said…