Scientists have known for some time that, far from being silent animals, mice emit song-like ultrasounds , the melodies of which help them find mates. But how do they learn them? Or are they already born knowing how to sing? To try to find out if the songs are innate or learned from their parents , the researcher Takefumi Kikusui and his colleagues from the University of Azabu (Japan) mixed two families of rodents, so that the offspring of each strain were raised by parents " adoptive ". Analyzing their songs after 10 to 20 weeks, Kikusui found that the younger ones sang the melodies of their genetic parents and not that of their adoptive parents, which points to an innate ability.
On the other hand, researchers from Northeasthern Ohio University (USA), led by Jasmine Grimsley, carried out a study to understand the changes that these songs undergo throughout development , which allow parents to distinguish young mice from grown ups. They thus discovered that, among other modifications, the syllable patterns of melodies became more complex. This phenomenon could be explained because mice learn them, but also because of the natural neuromuscular development they experience as they grow, the scientists conclude.
Both studies are published in the latest issue of the journal PLoS One .
