Male Mice Sing Ultrasonic Love Songs

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A grey house mouse. Researchers have proven that mice produce ultrasonic vocalizations for courtship that are structured like songs.
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THE GIST:

- Male mice use ultrasonic vocalizations to court available females.

- Since male mice song quality varies, the songs help females to choose the best mates.

- The research could lead to treatments for autism, since communication skills differ for mice as they do for humans.

Male mice drive females wild with ultrasonic love songs, suggests a new study.

Since song quality varies, the mice world has its Justin Timberlake-like stars that impress females with their talents more than other willing, but not so able, males do.

While no one is yet certain what makes a "hit love song" in the mice world, lead author Kerstin Musolf told Discovery News that "it could be a question of different syllable types or endurance in singing or a combination of both -- all together it could help the female to choose the best mate."

Musolf is a researcher in the Konrad Lorenz Institute for Ethology at the Austrian Academy of Sciences.

She and her team believe their study, which has been accepted for publication in the journal Animal Behavior, is the first to examine the ultrasonic vocalizations of wild-derived house mice. These calls have frequencies above those of sounds audible to humans and many other animals.

Using special equipment, the researchers recorded and observed offspring of house mice caught at three locations in Ganserndorf, Austria. When males got a whiff of scent from available, non-related, adult females, they sang their hearts out at varying degrees. Females were more attracted to songs crooned by unfamiliar males that weren't related to them.

Women sometimes flirt by pushing back their hair. Female mice do something similar by cleaning themselves vigorously all over.

"Individuals self-groom more in the presence of an odor of a highly receptive potential mate than that of a less receptive mate," explained Musolf. "Self-grooming may be associated with olfactory communication between groomers."

Females produce ultrasonic vocalizations too, "but only in a female-female context." These different calls help them to distinguish familiar individuals from strangers.

Both males and females produce audible squeaks too, but males only do this at the "beginning of courtship and, as far as I know, not with song-like features," Musolf said.

Ultrasound is not only inaudible to many predators, but it is also less likely to cause vibrations, which mouse-hungry animals, like snakes, can detect. Minks and weasels, however, are able to hear in the ultrasonic range, suggesting they can eavesdrop on mice.

The scientists suspect that other rodents, such as rats, produce ultrasonic courtship calls too.

Studies on these calls may surprisingly shed light on autism, a developmental disability marked, in part, by communication disorders. Jacqueline Crawley of the National Institute of Health and Maria Luisa Scattoni of the Istituto Superiore di Sanita in Rome have already found that certain mice, like some humans, are better at communication than others.

"We hypothesize that ultrasonic vocalizations may be a measure of social communication in mice," they wrote in a PLoS ONE study, adding that "delayed, reduced or unusual ultrasonic vocalizations in mice" could model the "impaired communication" seen in autism.

Crawley and Scattoni hope future studies on the vocalizations will enable identification of the genetic and environmental causes of autism, and allow scientists to evaluate proposed treatments for it.