ANDRZEJ KRAUZEOn October 5, 1998, more than 2,000 homing pigeons went missing, some straying from their lofts for weeks. They had been released at the start of two races—one from northern Virginia to Allentown, Pennsylvania, and another from western Pennsylvania to Philadelphia—but more than 90 percent of them didn’t fly directly home, as they normally do. “The race was a ‘smash’—the birds [didn’t] come back,” says Jonathan Hagstrum, a geophysicist with the US Geological Survey. “Normally, a smash is due to weather—if it’s raining, the birds land—but the weather was fine, everything was great, the birds just didn’t show up. . . . Nobody could explain it.”
Curious, Hagstrum, who read about the mysterious disappearances in his local newspaper, started poking around for possible explanations. It had previously been reported that pigeons could sense very low-frequency, or infrasonic, sounds. And Hagstrum knew that low-frequency sounds are continually being produced by collisions between waves in the deep ocean, which can generate vibrations in the earth that are transferred to the atmosphere and reflected from landmarks like hills and cliffs. “I think it’s going to produce a sound with a distinctive signature,” he says—something that might signal “home” to a pigeon. Perhaps there was some sort of sonic disturbance the day of the 1998 races, he thought.
He called the Pennsylvania Department of Transportation, but it had not been performing any blasting in the ...
