The Mystery Of The Missing Martins

When half a million songbirds didn't show up at their usual roosting spot this summer, I went looking for them. My search took me to the back roads of South Carolina, where I saw firsthand evidence of Shakespeare's influence on American ecology, met a society of strangely enthusiastic landlords, and learned a bizarre fact about the missing birds: They don't nest in nature anymore. They only breed in houses provided by humans.