What would happen if you took a bird that migrates south in the winter and put it on a plane and flew it in one day to where it normally migrates to? Would it stop there or keep moving south?
-- Dan, San Diego
As many times as ornithologists have tried this trick in the name of science, it's a wonder any bird knows where it's going any more. They've given coach-class tickets to Norwegian birds and sent them to France, Alaskan birds to Louisiana, California birds to Maryland and Korea, put blinders on them, stuck cotton in their nose holes, done everything but strap them to desk chairs and spin them around until they're too dizzy to stand up. Here's what they get (the simplified version). A bird who has migrated in years past will stay put if he ends up in his usual wintering grounds. They use stars, wind, climate, food availability, and other clues to recognize where they are. If you've taken them to a completely new place, they'll probably find their way back to where they should be using the same clues. But a fresh, new, just-out-of-the-egg bird would probably keep moving south until he reached the limits of acceptable habitat. BTW, the California-to-Korea birds were never seen again. Guess sparrows have their limits.