Humans aren’t the only species that tend to belt out an inebriated song or two after consuming alcohol — songbirds will get in on the act as well. But first, scientists had to get them drunk.
A study published last week in the journal PLOS One examined the effects of alcohol on the singing of the zebra finch. As the zebra finch, a songbird, learns to sing in a method analogous to the way humans learn to speak, researchers looked to get an insight into how alcohol affects cognitive function by observing intoxicated birds.
To get the birds effectively inebriated, researchers offered the zebra finches spiked juice, which the birds drank readily until their blood ethanol content was raised significantly. With the alcohol in their system, the birds began to sing, their songs were clearly slurred:
The strongest effects of alcohol on song were on amplitude and entropy, detectable over whole motifs and at the individual syllable level. The effect on entropy, in particular, indicates a destabilizing effect of alcohol on song production, disrupting a bird’s ability to maintain its normal acoustic structure of song and its component syllables.
Also of note was that, while alcohol had broader effects on areas such as amplitude and entropy, the effect on the syllabic structure of the birds’ songs were more varied. Zebra finches’ songs contain various syllables with different acoustic structures, which the study writes reflects “a diversity in the neural encoding and vocal production mechanisms the birds use for generating them.” As different syllables were affected across songs and individual birds, the researchers look to futher study whether alcohol may affect specific regions in the brain more than others.
The researchers hope to test further hypotheses on intoxication in humans based on the results from this study, including the ability to detect drunkenness by voice analysis.