Any good DJ knows playing the same song too many times at a party is a buzzkill. Likewise, male sparrows will remix and shuffle their set list to captivate their love interests. The songbirds keep track of each new melody they sing and switch up the order every 30 minutes to keep the ladies guessing, according to a study published last month in Proceedings of The Royal Society B.
A male sparrow's song is key to winning over a potential mate and competing for breeding territories. Previous studies have shown that female sparrows prefer a tune with complexity, vigor, and distinctiveness that showcases their suitor's smarts. But scientists weren't sure whether males were getting creative with their musical talent intentionally or not.
To analyze the patterns in the songbirds' serenades, researchers hiked into the woods in northwest Pennsylvania and recorded hours of chirping and trilling, reports Maggie Parkhill for CTV News. After recording entire discographies from more than 30 individual birds, the team went back to the lab and visually plotted the songs to identify the order in which sparrows sang songs and for how long.
The findings suggest male sparrows don't randomly sift through their tracks, instead they curate and design their own playlists. They found that bachelor birds avoid singing the same old tune by intentionally selecting and stringing together 6 to 12 different two-second soundbites during performances lasting up to 30 minutes, report Megan Lim, Michael Levitt, and Christopher Intagliata for NPR.
"I think that what's surprising about this is the scale," says Jon Sakata, an ornithologist at McGill University not involved in the study, to NPR. "You know, 20 to 30 minutes is quite a long time in terms of cycling through different song types."
Before repeating any song, the male sparrows will sing through their entire repertoire. For example, if a male used one tune ten times in a row, it would cycle through renditions of other songs before returning to the original sound he sang ten times, per a Duke University statement. Or if the sparrow only sang one song three times, it would cycle through shorter versions of other songs before returning to repeat the underplayed original.
This behavior demonstrates long-distance dependency, meaning whatever happens in the future depends on an action in the past. This cognitive ability is not seen often in non-human species. For sparrows, this means their upcoming queue is dependent on what songs were sang in the past 30 minutes.
Though normally meant to insult someone's intelligence, perhaps the title "bird brain" should actually be used as a compliment. Male sparrows seem to have incredible memory capacities and recall abilities, a statement explains. Other birds, such as canaries, can only remember about 5 to 10 seconds of previously played tracks, per CTV. The way song sparrows remember and plan their songs may be similar to human syntax and how our brains form connections to memorize language and communicate effectively, CTV News reports.
More research is needed to see if the male's song shuffling abilities give them an advantage when finding a mate. For now, the research team emphasizes its speculation and also suggests it may be a way to keep females listening and entertained, similar to how humans use music to occupy themselves at the gym.
"You've got your playlist for running, and the reason you've got that is because running is kind of boring," says study author Stephen Nowicki, a Duke University biologist, in a statement. "You know that these ten songs are going to keep you motivated, but if you are going to run for 20 songs long, why not shuffle it so the next time you don't hear the same songs in the same order?"