Nautilus: A Third of North America’s Birds Have Vanished

For weeks, Adam Smith had been crunching the raw data from more bird statistics than anyone had ever tried before—thirteen different bird counts and millions of radar sweeps. Suddenly he heard the musical chime that tells him his results are ready. He leaned across his desk, surrounded by enough high-powered computers to heat up his entire office, and stared at what could only be an impossible conclusion: Over the past fifty years, his calculations found, a third of North America’s birds had vanished.