The warblers left twenty-four hours before the devastating storm hit and flew in all directions, some as far south as Cuba. After the storm passed, they flew straight back to their nesting site—for some, a round-trip of almost 1,000 miles. The scientists conducting the study suggest that the birds may have been warned by the deep rumble of the superstorm when it was still 250 to 500 miles away, picking up on the strong low-frequency infrasounds generated by such tornadic storms. These can travel for hundreds to thousands of miles but are inaudible to humans.
