Human mothers often sing to their babies before birth, and so do mother wrens. But while humans may do this to enrich their offspring — and may not be certain that their baby even hears them — wrens are teaching their chicks a secret language — and the young ones definitely get the message.

According to an article in Audubon Magazine, some Australian avians pass an oral password of sorts to their young as they incubate in their eggs. Once the eggs have hatched, the chicks use these sounds as a feeding call to make sure they don’t get skipped for dinner. This helps the mother distinguish her offspring from imposters such as cuckoos, whose parents may have dumped them in the wren’s nest to skirt parental duties.

While all of the baby birds may beg for food, only the original nesters know the secret code. Sometimes the cuckoos hatch before the wren chicks and evict them from the nest. But because these foreign babies don’t know the password, the mother wren will abandon the nest to start a new home elsewhere. One can only hope that the cuckoo parents return to take on their own responsibility.

Audubon compares this code to a last name, and reports that female wrens also teach the code to their mates and then use it to communicate as a family. In that way, birds are very similar to humans; in fact, they’re far more likely than mammals to create a “traditional” nuclear family. And while it may seem cruel to abandon hungry chicks of any species (would a human mother simply adopt the strangers?), it’s hard to imagine any mother putting the needs of another baby before her own — so maybe we’re not all that different.

image: 0+ Imaging