Sure enough, when the birds got buzzed, they started slurring their songs, not unlike your friends belting out "You Oughta Know" on karaoke night. Interestingly, some syllables of the birds' songs were more messed up than others, meaning alcohol could affect different parts of the brain in different ways.
For the record, the zebra finches willingly drank this stuff.
"At first we were thinking that they wouldn't drink on their own because, you know, a lot of animals just won't touch the stuff," researcher Christopher Olson told NPR. "But they seem to tolerate it pretty well and be somewhat willing to consume it."