It's always a good idea to listen to your mother, but that goes double for baby fairy-wrens even before they are hatched.
If those fairy-wren babies want to be fed, they need to have a password—a single unique note—taught to them by their mothers from outside the egg. The nestlings incorporate that password right into their begging calls, according to researchers who report their discovery online on November 8 in Current Biology, a Cell Press publication.
This remarkable example of prenatal learning is an adaptation that apparently allows fairy-wren parents to discriminate between their own babies and those of parasitic cuckoos who have invaded their nests. Females also teach their mate and any helpers the password by singing it to them in a "solicitation song" performed away from the nest.
"Parents and others attending the nestlings will only feed them if their begging calls contain the learned password," said Sonia Kleindorfer of Flinders University in Australia. Otherwise, the parents simply abandon the nest and start again.
Kleindorfer and her colleagues originally stumbled onto this scheme when they noticed something unexpectedly odd while studying nest predators and alarm calls: superb fairy-wren mothers calling to their unhatched eggs. The researchers later found that fairy-wren nestlings' one-note begging calls differed from one nest to another. The researchers' key breakthrough was the realization that the unique element in each female's incubation call was the basis of the begging call of her brood. In other words, it was a password.
Cross-fostering experiments, in which clutches of eggs were swapped between nests, showed that the nestlings produced begging calls that matched their foster mothers, not their biological mothers, evidence that the passwords were indeed learned. The researchers found they could also prevent attending parents from feeding their nestlings by placing a loudspeaker under the nest that played the wrong begging call.
The findings show that even traits that appear innate may actually be learned. Such an ability could have real evolutionary implications for the superb fairy-wrens, and more broadly.
"We show that females that guard and teach the embryo could increase the transmission efficacy of female cultural traits," Kleindorfer explained. "In systems with uniparental care, caretakers of embryos will have more opportunity to pass on female memes, or 'messages,' to the embryo." And, she added, that means that mothers have a special ability to transmit not just genes to the next generation, but also memes.
Cell Press: http://www.cellpress.com
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
The first ever trial of reprogrammed stem cells is put on hold while scientists investigate whether the procedure caused a potentially cancerous mutation
Researchers were amazed to see a wild polar bear stay under the water for so long while stalking its next meal
Study is one of first to track where in the ocean predators pick up different chemicals
When amnesia strikes, people can forget everything about their life, including their name. But what causes memory loss? And what happens to people who lose themselves for an hour, a few months – or even for ever?
Tooth unearthed by 20-year-old volunteer hailed as major discovery by paleoanthropologist overseeing dig at Arago cave near Tautavel
Autistic children are just as good at reading emotions from the body as those without – they just don't like the closeness that interpreting emotions from faces requires
Individual cells can be made to act like tiny lasers, offering a more accurate way to tag and monitor tumour cells, for example
If you want to know the secret behind the success of Tyrannosaurus rex and its meat-eating dinosaur cousins, look no further than their teeth.
A recent article argued that sexuality is down to choice, not genetics. But the scientific evidence says otherwise, and points to a strong biological origin
When I hear the word “sabertooth”, my mind immediately jumps to the great sabercats who sliced through throats …