If there's one thing everyone knows about baby birds, it's that you're not supposed to pick them up. If you do, the mother bird will smell the residue of your stinky human hands on her baby, and leave the piteously crying chick there to die, right?
Wrong, says Miyoko Chu, a biologist at the Cornell Lab of Ornithology. "Birds don't have a very strong sense of smell ," she said, "so you won't leave a scent that will alarm the parent."
In fact, contrary to what our parents may have told us, most bird parents are unlikely to abandon their chicks over a little human fiddling. "Usually, birds are quite devoted to their young and not easily deterred from taking care of them," Chu said.
But before you put on your Bird Rescuer costume and start saving the day, Chu suggests you shouldn't go around picking up every baby bird you see. Baby birds may look stranded when in fact their parents are hiding close by. In fact it's very common for young birds to leave the nest before they're ready to hit the skies.
"If you back up and watch them," Chu said, "in a lot of cases the parent will come back and feed the young and protect it."
And your handling of the bird might be doing more harm than good, said Tom Hahn, an ornithologist at the University of California in Davis. "A much bigger risk to the babies, if humans mess around with them, is that the activity of the human around the nest may attract the attention of predators, which may subsequently come get the babies," he says.
If the chick is clearly out of the nest too soon, the rescue-minded should call a local wildlife rehabilitator before trying to relocate the bird themselves. But, Chu said, if the bird is in a highly unsafe area, such as on a road or in a neighborhood full of cats, it's fine to gently pick the baby up and put it back into its nest.