Birds talk to eggs, no yolk!
MOVE over Tiger Mums and Helicopter Parents, new Deakin research shows zebra finches begin training their young while they’re still in the egg.
Researchers from Deakin’s Centre for Integrative Ecology found the Australia desert bird uses a specific call during the incubation period to warn their embryos about the temperatures they will face upon hatching.
The newly hatched birds then use this heads up to alter how much food they receive and weight they gain.
The paper, published in the latest edition of Science magazine, argued that the previously unknown reason for embryonic hearing could prove critical in a warming climate.
It is a crucial first step in understanding a potentially wideranging and important phenomenon.
“Embryos’ capacity to hear, and even learn, external sounds has been known since the 1960s, in humans and animals alike, but the implications of hearing before birth for adaptation to post-hatching conditions had not been suspected,” research team leader and Australian Research Council Future Fellow Professor Kate Buchanan said.
The study recorded more than 600 hours of audio from inside the nests of zebra finches and found the birds only called to their eggs once the mercury exceeded 26C.
“Calling only occurred within five days of hatching, once embryos had presumably developed hearing capacities,” lead-author Dr Mylene Mariette said.
“This suggests that parents are deliberately communicating with their embryos about the heat.
“Astonishingly, the calls birds heard as embryos impacted on these individuals until adulthood, up to two years later.
“We found that adjusting their growth rate to ambient temperature allowed experimental birds to themselves produce more young as adults.”
The study also found those who had been warned about the heat went on to breed in hotter areas than the control birds.
“Our work highlights that acoustic environment may have a much stronger impact on development than we currently realise,” Dr Mariette said. “This is also the first evidence that parents can adjust the development of their offspring to ambient temperature in warm-blooded species.”