Tipsy Birds 'Slur' Their Songs Like Drunk People Slur Their Words

If you're one of scientist Christopher Olson's lab birds, you could get used to this.

On a recent morning, Olson and his colleagues at Oregon Health and Science University fed a group of zebra finches a mixture of juice and alcohol until their blood alcohol levels reached about .06% (in bird terms, that's sufficiently tipsy). They were studying how the booze affected their vocalizations.

We still don't know why boozing makes us slur our own speech - most assume it's because it slows down overall brain activity, but the precise connection between garbled speech and drunkenness has yet to be nailed down. The new research on birds may provide a clue.

Scientists have studied finches for decades to learn more about how humans communicate; the way birds learn to sing is remarkably similar to how we learn to talk. A study published earlier this month narrowed in on the connection - birdsong and human speech, it turns out, are even controlled by the same genes.

But does booze jumble birds' sweet songs the same way it garbles our tongues? The answer seems to be yes, according to Olson's research.

Finches who drank the alcohol solution became "a bit less organized in their sound production," Olson told NPR. Their tunes also became a bit more muffled than usual, he wrote in his study.

Similarities Between Birds And Humans

While we rely on speech to communicate, very few other mammals use vocalizations at all. Among us warm-blooded folk, only dolphins, bats, and three species of birds use some form of speech or song. Most of these animals are difficult to study.

When it comes to learning how to vocalize sounds, however, zebra finches and humans have a remarkable amount in common, making them ideal candidates for research.

For starters, both of us spend a fair amount of time outside the womb (or egg) before we begin to form sounds. During this time, our brains develop specialized circuits that allow us to speak (or sing). We learn to make sounds by listening and watching our parents. Zebra finches, similarly, learn to tweet with the help of a tutor. And both of us mimic what we hear, so that with practice, the sounds we make get better over time.

Boozy Tunes

Using this foundation as a jumping off point for their research, Olson and his team studied how alcohol would affect both the birds' singing behavior - how often they sang, for example - and the sound of their songs. While the booze didn't coax them into singing more or less frequently, it did affect the quality of their tunes.

With alcohol, the researchers wrote, the birdsong "amplitude significantly decreased and entropy increased." In other words, the birds' tunes became a bit hushed, and their songs grew less harmonious and more jumbled.

Olson hopes his study will help scientists explore how alcohol affects human speech in the future.