For the past two summers, Cornell sophomore Andy Johnson has slogged through miles of Canadian wet tundra, battling hordes of mosquitoes in search of small devices that hold clues to the epic migrations of birds. The devices are on the legs of Hudsonian Godwits—and the only way to recover them and retrieve the data is by capturing the birds at their nests.

The devices have tiny light sensors that record the birds’ locations wherever they go. The team, led by Cornell graduate student Nathan Senner, has recovered 34 data loggers so far. One of them revealed that female “LP” flew nonstop from Tierra del Fuego, Argentina, to Freeport, Texas, on a 7-day, 6,100 mile flight—before continuing another 2,050 miles to her nesting grounds in Churchill, Manitoba.

This summer, nest predation prevented the team from recovering many more data loggers, but they gained new insights about the lives of the chicks. Using tracking devices, they followed chicks from 12 families—and noticed early signs of their knack for long-distance travel.

“Within an hour of hatching, the chicks have already left the nests to gorge on whatever insects and invertebrates they stumble across,” Andy wrote in "Fen Filled Summer" on the Cornell Lab of Ornithology’s blog. “Amazingly, we found a chick nearly 2 miles from its nest less than 36 hours after it had hatched, running on oversized legs, head bobbing between grassy hummocks.”

The young will double their body weight every week until they can fly. They’ll arrive in Tierra del Fuego, more than 8,000 miles away, by the time they’re about 4 months old.