CIE Spotlight: It’s hot baby! Bird parents call to their eggs to prepare their young for upcoming heat

ZF pair at box large
Credit: Donna Squire

A new study, published today in Science by CIE members Dr Mylene Mariette and Professor Kate Buchanan, reveals that prenatal sounds matter a lot more than we realised for young development, and this may prove very handy for adaptation to a warming climate.

In their study “Prenatal acoustic communication programs offspring for high post-hatching temperatures in a songbird”, Mylene and Kate showed that zebra finches can tailor the growth of their nestlings to temperature by calling to the embryos before hatching.

The zebra finch is an iconic bird of the Australian arid zone that breeds at any time of the year, whenever rain makes to desert greens up. Parents may breed at 15ºC or 35ºC, but the embryos do not know about it, as they are kept at a constant 37.5 by their incubating parents.

This study showed that incubating parents produce a special call, when temperature raises above 26ºC. They only call a few days before hatching, when embryos might be developed enough to hear them.This suggests that parents are deliberately communicating with their embryos about the heat.

When the researchers exposed the eggs to acoustic playbacks in artificial incubators, they discovered the embryos were paying attention to their parents´ calls.

Nestlings hatched from eggs exposed to this heat-warning call adjusted their growth to temperature in a different manner than control nestlings that heard another type of parental call

According to Dr Mylene, this research shows that the calls birds heard as embryos impacted on these individuals until adulthood, up to two years later. Such profound and long lasting effects of prenatal acoustic experience had never been demonstrated before.

Want to know more? A video from AAAS Science explains how the parents talk to their chicks before birth:

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