With thousands of newly-hatched 17-year cicadas blanketing the Eastern U.S., residents would be forgiven for not noticing a less conspicuous absence: birds. Bird surveys have repeatedly shown a mysterious trend of a population downtick in areas of cicada emergence.
It's the exact opposite of what might be expected---crows, blue jays and cardinals are among the species affected, and they feed on insects. And it's fascinated ornithologist Walter Koenig for years. “The birds are just not coming in there to eat them,” says Koenig, a senior scientist at the Cornell University Laboratory of Ornithology. “Why aren’t the birds taking advantage of the cicadas? The fact that there may not be birds around seems like a good explanation.”