Backpacks for Birds Making It Grow Minutes

To discover where prothonotary warblers spend their winters, Beidler staff devised an ingenious system. Several birds, weighing about half an ounce, have been fitted with tiny backpacks that record information about where they go. The devices don’t transmit coordinates, they would be too heavy. This system is dependent on having some of the birds, with their site fidelity, successfully making the trip south and returning to the place of their birth. Then they’re trapped, the backpacks removed, and information retrieved.