The birds in Gilbert, Minn., are berry, berry drunk.

With the town buzzing about erratic avian behavior, the police chief in the Iron Range city of 1,800 residents took to Facebook this week to let the public know what was going on.

Turns out, the birds have been getting tipsy on fermented berries.

"The Gilbert Police Department has received several reports of birds that appear to be 'under the influence' flying into windows, cars and acting confused," Chief Ty Techar wrote Tuesday. "The reason behind this occurrence is certain berries we have in our area have fermented earlier than usual due to an early frost."

Techar's post drew dozens of comments from area residents who had been wondering what was going on.

"This explains why I have hit 7 birds with my car this week," said Rebecca Rankila Warwas.

Special to the Star Tribune, Star Tribune
Cedar waxwings such as this one are among the few migratory birds that eat fruit, which has led to problems in Gilbert, Minn.

"I was going to say something … but I thought I was crazy!!!" wrote Betsy Walli. "This has been happening to me!"

Tipsy birds aren't unheard of, said Jim Williams, who writes the "Wingnut" bird blog for the Star Tribune. But most migratory birds prefer a diet of nuts and insects, meaning the avian alcohol problem is limited to a few species that love fruit, such as cedar waxwings and robins.

"Every once in a while you get a [fruit] tree that ferments," Williams said. "It's like drinking wine, I guess."

In fact, a number of animals seem to enjoy fermented fruit. According to National Geographic, white-tailed deer in apple-growing regions have been seen stumbling through the forest after eating overripe apples. Butterflies are attracted to beer, and moths to wine, while bats are known to feed on fermented fruit and nectar.

A 2012 study in the academic journal "Science" found that fruit flies were more likely to drown their sorrow in alcohol when they were sexually rejected. Unsuccessful flies were more attracted to ethanol than flies that had successfully mated.

As for the birds, they usually fly above automobile traffic and are alert enough to avoid cars when they encounter them. But add a dose of fermented berries, and they lose their edge.

"They're flying low, they're not flying very well," Williams said. "It's drunken driving, except they're flying straight into people's windshields.

"They're behaving like drunk people."

John Reinan • 612-673-7402