Female birds 'jam' their partners' flirtatious tunes
Female antbirds sing over the songs of their male partners in a bid to prevent their flirtatious messages from reaching single female birds, a new study has found.india Updated: Mar 13, 2009 13:15 IST
Female antbirds sing over the songs of their male partners in a bid to prevent their flirtatious messages from reaching single female birds, a new study has found.
The study also found that males respond to that interruption by singing a different tune.
According to researchers, the findings offer the first evidence that such 'signal jamming' and 'jamming avoidance' occur between mates.
"In human terms, signal jamming is most commonly associated with attempts to scramble information in radio, radar, or cell phone signals," said Joseph Tobias of the University of Oxford.
"The females in our study try to do a similar thing with the songs of their partner, but the overall situation is more analogous to a wife continually interrupting her husband to stop him from flirting with a single woman," he added.
In a series of playback experiments, the researchers found that resident pairs of antbirds sing coordinated duets when responding to rival pairs. But under other circumstances, cooperation breaks down, leading to more complex songs.
Specifically, they report that females respond to unpaired sexual rivals by jamming the signals of their own mates, who in turn adjust their signals to avoid the interference.
Tobias said the females' attempts to jam their partners' songs are presumably intended to make the males less attractive, or to make it clear that they are 'taken.'
He added that the results in antbirds may have broad implications for understanding how communal signals have developed over evolutionary time in many animals, and perhaps even in humans.
First, Tobias said, the findings reveal that group signals such as duets and choruses represent a subtle blend of cooperation and conflict. The balance between those two forces depends on the context.
Their study also suggests that if there is some conflict in the system, then multiple singers can combine to produce rhythmic, precisely coordinated, and increasingly complex songs simply by avoiding overlap.
"Most evidence points to vocalizations in early humans having a function in both mate attraction and resource defense, so it seems plausible that 'signal jamming' and especially 'jamming avoidance' played a role in our evolutionary history. If so, our results may help to explain the first steps towards complex, coordinated group signals in humans, which themselves are the likely forerunners to modern music," Tobias said.
The study has been published online on March 12th in Current Biology, a Cell Press publication.