A bout of heavy drinking will cause an individual to slur one’s speech — a fact that appears to apply to birds as well.

A study published in PLOS ONE last week finds that giving zebra finches juice spiked with alcohol to the point that they reach a blood alcohol level of about .08 percent — which is the legal limit for driving a car in many states — causes them to slur their singing in a way similar to the way humans slur their speech after drinking alcohol, according to the Washington Post.

The purpose of the study was to learn more about human speech, as birds learn how to sing in a way similar to how humans learn to talk — they even rely on the same genes. This similarity has allowed scientists to study speech in humans without actually using babies for research.

Most people know that alcohol makes it difficult for people to speak correctly and clearly, but not much research has been conducted on this phenomenon, mostly because most animals can’t form speech like humans and thus don’t give researchers anything to study.

At first, scientists who worked on the study doubted that the birds would drink any substance spiked with alcohol, but they found that the birds tolerated it well.

Once they reached a point of inebriation, their songs started to slur, and the volume of their singing lowered. Their songs were also less organized, according to the research.

Zebra finch songs use specific syllables with distinct acoustic structures, which became more garbled in finches that had consumed alcohol. However, scientists noted that it affected some syllables were affected more than others.

What does this mean biologically? Scientists think it could indicate that alcohol affects certain parts of the brain differently, causing some sounds to come out garbled and others not as much.

Researchers want to continue looking into the issue to find more evidence for this theory, as well as find out alcohol prevents the birds from learning new songs.

The zebra finch is a common bird native to Central Australia and has a range that spans most of the continent, preferring drier areas over the moist southern part of the country. It is also sometimes found in Indonesia and East Timor, and has been introduced to the United States, Brazil, Portugal, and Puerto Rico.

Zebra finches are considered boisterous singers with loud voices, possibly why they were chosen for the study. Their calls are described as a loud “beep” or an “a-ha!” The song usually features a few small beeps that build into a more rhythmic song that can be quite complex in males. The finches ahve their own distinct song, and related birds will sing similar songs.

The songs are used as a mating call. They will hiss to ward off creatures that threaten their territories.