As industrial-scale farms flourish in the European Union, its fields have grown quiet—robbed of the birds that once filled them with song. Since 1980 the number of birds that typically inhabit Europe's farmlands has shrunk by 55 percent. And in the last 17 years alone, French farmland-bird counts dropped by a third -- a "level approaching an ecological catastrophe," according to a recent survey.

Intensified agriculture is driving the losses. Habitats where birds once bred, nested, and wintered now bear crops, and pesticides have killed off birds' prey. In the past 27 years Germany has lost 75 percent of its flying insects by mass. Even avian species that typically adapt to humans have dwindled on farms, suggesting that the land is less able to sustain all kinds of birds.