SCIENTISTS HAIL GOLDEN AGE TO TRACE BIRD MIGRATION WITH TECH

A plump robin wearing a tiny metal backpack with antenna hops around a suburban yard in Takoma Park then plucks a cicada from the ground for a snack.

Ecologist Emily Williams watches through binoculars from behind a bush. On this clear spring day, she’s snooping on his dating life. “Now I’m watching to see whether he’s found a mate,” she said, scrutinizing his interactions with another robin in a nearby tree.

Once the bird moves on at season’s end, she’ll rely on the backpack to beam frequent location data to the Argos satellite, then back to Williams’ laptop, to track it.

The goal is to unravel why some American robins migrate long distances, but others do not. With more precise information about nesting success and conditions in breeding and wintering grounds, “we should be able to tell the relative roles of genetics versus the environment in shaping why birds migrate,” said Williams, who is based at Georgetown University.

Putting beacons on birds is not novel. But a new antenna on the International Space Station and receptors on the Argos satellite, plus the shrinking size of tracking chips and batteries, are allowing scientists to remotely monitor songbird movements in much greater detail than ever before.

“We’re in a sort of golden age for bird research,” said Adriaan Dokter, an ecologist at Cornell University who is not directly involved with Williams’ study. “It’s pretty amazing that we can satellite-track a robin with smaller and smaller chips. Ten years ago, that was unthinkable.”

The device this robin is wearing can give precise locations, within about 30 feet (about 10 meters), instead of around 125 miles (200 kilometers) for previous generations of tags.