Zebra finches slur while singing after consuming alcohol, a new study has found. Like humans at a karaoke bar, finches have trouble singing well after consuming alcohol. Researchers provided captive finches with alcohol mixed with fruit juice and water.

Blood alcohol levels in the birds who consumed the drink reached between 0.05 and 0.08 percent. This is the same level at which charges of driving under the influence take effect in many states. In an audio recording of finches in the experiment, songs are heard rising and falling in volume, as well as becoming slurred at times. Olson compares this sound to a college student calling their roommate, asking for a ride home from a bar.

"We just showed up in the morning and mixed a little bit of juice with 6 percent alcohol, and put it in their water bottles and put it in the cages. 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. But they seem to tolerate it pretty well and be somewhat willing to consume it," Christopher Olson from Oregon Health and Science University said.

Birds in some areas of the world are able to obtain alcohol as temperatures drop, and berries trapped on bushes experience the first frost. As the fruits freeze, the sugars within them can turn to alcohol, which is consumed by wild birds.

"Most birds likely just get a bit tipsy, and very few people would be able to pick them out as intoxicated. However, every now and then, some birds just overdo it," Meghan Larivee from Environment Yukon, a governmental agency in Canada, said.

In Whitehorse, Yukon, a number of Bohemian waxwings had to be placed into wildlife "drunk tanks" for their own safety, after consuming fermented berries. The creatures were cared for, in specially-adapted hamster cages, by that region's Animal Health Unit. This is a regular occurrence in the region, as birds flock to the area just as berries are fermenting.

"They cannot coordinate their flight movements properly or at all, and they are unable to walk in a coordinated way," Larivee told National Geographic.

Those that get drunk in the wild are often found with berry-stained beaks, and recover in a few hours.

Finches are often used by researchers examining actions of the human vocal system, including patterns of learning. Future research will examine how alcohol can alter learning patterns, including the ability to learn new songs. This future experiment could be compared to measuring the test-taking abilities of a student the morning after a long night of drinking.