Excerpts:
Now, a new study in the journal Science emphasizes another reason the long voyage may be worth it for birds: fewer predators.
Titled “Lower Predation Risk for Migratory Birds at High Latitudes," the study finds that, the farther north birds go in the Arctic, the lower the risk of predation. Fewer predators mean that vulnerable young have greater chance of survival.
Even accounting for the huge energy cost of the long voyage, having young in the Arctic improves reproductive success.