‘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. “Well, that can’t be right,” he thought. “I must have made a mistake somewhere.”

Smith, one of the hemisphere’s top specialists in bird populations, just sat for a while in his cluttered cubicle at the Canadian Wildlife Service, which was decorated with caribou antlers, a musk-ox skull, and early drawings from his twin boys. Then it dawned on him. “This would be a massive change, an absolutely profound change in the natural system,” he said. “And we weren’t even aware of it.”…’ ( Anders Gyllenhaal via Nautilus )