The musical tweets of a Song Sparrow’s playlist are more complex and akin to human language than anyone realized.
A new Duke University study finds that male Song Sparrows deliberately shuffle and mix their song repertoire to keep it interesting for their female audience.
Song Sparrows are a common songbird throughout North America, but only males sing. They use their song to defend their turf and court mates.
Song Sparrow’s Playlist
Think about those playlists you meticulously create and share with friends. Playlists are one of the most intimate things we share and tell you a lot about someone.
Research shows that male Song Sparrows keep track of the order of their songs and how often each one is sung for up to 30 minutes so they can curate both their current playlist and the next one.
When wooing mates, Song Sparrows belt up to 12 different two-second songs. A repertoire takes nearly 30 minutes to get through since they repeat the same song several times before going on to the next track.
Males vary the number of repeats and shuffle the order of their tunes each time they sing their discography. However, researchers don’t know whether males change their song order and repeat by accident or design.
Learning How Song Sparrows Mix Their Tunes
So researchers load up their recording gear and trek to the backwoods of northwest Pennsylvania to get data to learn if the birds intentionally shuffle and mix their tunes.
They set up mics pointing to the trees and patiently wait for five hours a day.
After recording the full suite of songs from more than 30 birds, the team pores over visual spectrographs of the trills to analyze how often each song was sung and in what order.
The first clue finds males generally sing through their entire repertoire before repeating a song. This indicates that males keep tabs on their tweets to avoid repetition, much like a Spotify playlist.
Clues to Creating the Perfect Songbird Playlist
Researchers also find that the more a sparrow sings its song, the longer it takes to get back to that song, possibly to build up hype and novelty once that song plays again.
For example, if a male sings Song A 10 times in a row, he sings even more renditions of his other songs before returning to Song A.
Alternatively, suppose a bird warbles Song A three times during a set. In that case, a male Song Sparrow recites a shorter rendition of the rest of his repertoire, returning to the still novel and underplayed Song A.
These findings indicate that Song Sparrows possess a scarce talent with an equally uncommon name: long-distance dependencies.
Meaning what a male Song Sparrow sings at the moment depends on what he sang as much as 30 minutes ago. That’s 360 times larger memory capacity than the previous record holder, the canary, who can only juggle about five seconds worth of song information.
Findings are inconclusive whether better shuffling ability gives male Song Sparrows an advantage at finding love. Perhaps females maintain interest in a mate who mixes it up more and is less likely to sneak off with another male.
Whatever the reason, sharing music is a form of intimacy, and humanity has been doing it with mixed tapes, boomboxes, CDs, and playlists for as long as we can remember. Clearly, birds mastered the art of the playlist from the moment they learned to sing, and it took humans millions of years to catch up.