Adolescents the world over are known for ignoring family traditions. Now, researchers have found that it's not just human teenagers who sing to their own tune. Indris, an endangered species of lemurs found in Madagascar, form family choirs, but while most of the family channels the collaborative Jacksons, the adolescents seem to be auditioning for some kind of Michael Jackson solo career. And you might be able to guess the reason why.
Researchers studied 21 different groups of indris in four areas of Madagascar, recording nearly 500 songs which were then analyzed to identify co-singing, overlapping, rhythm and pitch. Indris, one of the few primate species that sing, live in family groups with a dominant male-female pair, their offspring and maybe a couple of other young adults. It's the perfect setup for family sing-alongs. Males and females both sing, carefully coordinating their tunes, in what researchers say plays a part in defense of the group's territory and group formation.
As with humans, male and female indris have different parts to sing in the choir, but in this case, the males hit the high notes more often than the females. The overlapping singing is thought to show the strength of the group and keep other indris groups from encroaching on family stage. You can hear some of the piercing singing (actually sounds more like wailing) in the video below:
"The chorus songs of the indri start with roars that probably serve as attention-getter for the other singers and continue with modulated notes of that are often grouped into phrases," says Marco Gamba, a senior researcher at the Department of Life Sciences and Systems Biology of the University of Turin, Italy, and one of the study authors, in a press release.
Except younger ones can't help but sing their own tune. While the rest of the family synchronizes their song, these youngsters are in antiphony (an alternating, almost call-and-response pattern) to the rest of the group, swapping notes with mama and papa.
"Synchronized singing doesn't allow a singer to advertise his or her individuality, so it makes sense that young, low-ranking indris sing in antiphony," says doctoral student Giovanna Bonadonna, another of the study authors, in the news release. "This lets them advertise their fighting ability to members of other groups and signal their individuality to potential sexual partners."
Advertising their abilities to fight and have sex? Sounds like young folks in a lot of animal groups, including humans. Yet while these young indris advertise their individuality, they still do so in the context of a cohesive group, enabling them to still sing "We Are Family."