London, August 17 : Male zebra finches with the sweetest song are more likely to win females because singing ability advertises intellectual prowess, say researchers.
Neeltje Boogert, a researcher at McGill University in Montreal, says that the males who sang the most complex melodies during a study were found to be quicker at solving a problem to find food.
"Females might use song complexity as an indicator of how smart the male is," Nature magazine quoted her as saying.
While making a presentation on her study at the International Behavioral Ecology Congress at Cornell University in Ithaca, New York, Boogert claimed that her experiment was the first to test the idea that fancier songs showcase higher general intelligence.
During the study, Boogert and her colleagues recorded 27 male zebra finches serenading a female.
The researchers said that each male sang a unique tune over and over.
Upon analysing the songs to count how many 'elements' each finch used, the researchers found that melodies ranged from a minimalist eight elements to a florid 19.
The finches were later exposed to a puzzle: the birds had to peer into small wells in a wooden board wherein the researchers had hidden millet seeds, and in later trials had to pry lids off the wells to get the snack.
Boogert noted that some figured it out in four tries, while others still had not mastered the lid after 17 attempts.
She said that the birds with more elements in their songs solved the puzzle in fewer trials.
Based on her observations, she came to the conclusion that the ability to spot and prise out food in dense vegetation or mud was just the sort of thing a female might be looking for - skills that would help feed her chicks, and genes that would make the chicks good foragers when they grew up.
"Neeltje is the first to experimentally demonstrate a link between the expression of song and some aspect of cognition that really matters. It's a really important study," says Steve Nowicki, who studies bird behaviour at Duke University in Durham, North Carolina, and was not involved with the project.
The researchers are now planning to investigate whether the relationship between song and smarts holds true for wild birds.
"What females are really interested in is how smart you are. As an academic, I like to see that message," Nowicki says.