Baby birds can identify nearby sounds even before hatching, reveals new study

New research published in the Philosophical Transactions of the Royal Society has disproved the belief that birds start learning only after they break open their eggs as experts discovered that some bird species are capable of prenatal sound perception. According to a report by Science News, ecologists first came to know about the surprising characteristics of the bird after Sonia Kleindorfer of the University of Vienna found out that superb fairy-wrens intentionally sang to their eggs. Kleindorfer and her team also discovered that the unhatched wrens even learned vocal passwords for distinction among species. 

Heart rate of responsive birds in eggs dropped

In this study, the team of researchers led by behavioral ecologist Diane Colombelli-Négrel turned to four species of birds- Japanese quail, little penguins, red-winged fairy-wrens and Darwin’s small ground finches. As per Science News, this study followed the footsteps of Colombelli-Négrel's previous research where she observed the embryonic heart rate of fairy-wrens a decade ago. Heart rates are generally observed in human and bird embryos as a drop in the rate indicates attention to a stimulus. In her previous observation, Colombelli-Négrel had noticed that the unhatched selected species showed a slow heart rate in response to calls from their own species as compared to that of others.

As for the new study, the researchers separated 109 eggs and played sounds of birds from their respective species while comparing their heartbeats. The results showed that all the embryos experienced a drop in heart rate and became habituated to sounds of their own species. Lead researcher Colombelli-Négrel said that responses from penguins and quail embryos were unexpected as they are vocal non-learners and have calls that are genetically programmed from birth. Experts speculated that response from these two species must have something to do with survival. Meanwhile, studies have also suggested that some birds are even opting to 'shape-shifts' in order to survive climate change. 

Shapeshifting in birds

Published in the journal Trends in Ecology and Evolution, the findings of the study revealed that shapeshifting has been reported among birds especially among Australian species of parrots. It said that since 1871, there has been a 4 to 10% increase in the beak size which also coincides with the summer temperature each year. Other changes in mammalian species including an increase in tail length in wood mice and leg size increase in masked shrews have also been reported.

(IMAGE: PIXABAY)