To capture the birds’ calls, Diane Colombelli-Négrel was setting up nests for spectacular fairy-wrens when she observed something peculiar a decade earlier. Despite the fact that it would have been safer to stay silent while they incubated their eggs, mother fairy wrens nevertheless sang to pass the time.
Colombelli-Négrel, a professor at Flinders University in Adelaide, Australia, admits that the discovery was “a bit of an accident.” Could the baby birds be learning sounds or songs before they even hatch? She wondered.
Experts have debated when in life children begin to distinguish sounds. Humans have always been able to tell apart their mothers’ voices.
To explain the maternal guidance role in the learning of song in some species of birds, such as the superb fairy wren (Malurus cyaneus), the popular belief has been that the sound perceptions that the chicks rely on did not start until after they had hatched.
Avian ecologist Sonia Kleindorfer of the University of Vienna says, “We knew we were on to something when we discovered that parent birds were singing to their eggs.”
Previous research, led by Colombelli-Négrel, Kleindorfer, and others, discovered that fairy wrens unhatched in nests use a vocal “password” learned by their mother to differentiate against nestlings of the invasive cuckoo.
In addition, the 2014 study revealed that the unhatched magnificent fairy wrens were able to discern between songs of their own species and those of others.
The brown bird is perched on Diane Colombelli-hand. Négrel’s
For nearly a decade, Diane Colombelli-Négrel, the behavioral ecologist pictured in the Galapagos, has studied the wonderful fairy wrens’ sounds they make when incubating their eggs.
Katharina Peter’s New findings indicate that this talent extends beyond amazing fairy wrens. At least four different kinds of birds can identify sounds which are relevant to their own group even before they hatch, according to study published in the October 25 Philosophical Transactions of the Royal Society B.
A vocal learning neuroscientist who was not involved in the study, Wan-chun Liu of Colgate University in Hamilton, N.Y., was taken aback by the findings, which came as a shock to many birdsong specialists.
It seems as though even in the embryonic stage, they are learning by listening,” he explains.
Decreased embryonic heart rate is known to be related to the attention of animals, including humans and birds. The heart rate of fairy wren hatchlings changed in response to the calls of their own species, but not of others, as a study by Colombelli-Négrel and his colleagues has shown.