Reports of erratic bird activity prompted the Gilbert Police Department to issue a news release Tuesday.

Police Chief Ty Techar wrote that the department had received calls about "birds that appear to be under the influence, flying into windows, cars and acting confused."

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He said probably a half-dozen people contacted his department Monday with concerns about apparently disoriented birds flying into buildings and cars.

Not to worry, he said. Techar attributed the strange behavior to an early frost. Starch in the frozen berries is converted to sugar, and when they thaw again, yeast can enter the fruit and accelerate fermentation, yielding alcohol.

All this, before many birds have migrated out of the area, apparently has resulted in widespread avian inebriation, as the feathered flocks gorge on spiked fruit, mostly mountain ash berries.

Laura Erickson, a Duluth birding expert, said waxwings, robins and thrushes often are some of the most prone to become tipsy, as they commonly feed on such berries.

"Birds actually do get literally intoxicated when they eat berries that have started fermenting, and that does lead to drunken behavior," she said.

Techar said occasional reports of loopy birds are nothing new at this time of year, but weather conditions this fall have served up more than the typical share of alcohol-laden fruit.

"There is no need to call law enforcement about these birds, as they should sober up within a short period of time," he wrote.

"However, we would like you to call the Gilbert Police Department if you see the following," Techar added, obviously tongue in cheek:

• Heckle and Jeckle walking around being boisterous or playing practical jokes.

• Woodstock pushing Snoopy off the doghouse for no apparent reason.

• The Roadrunner jumping in and out of traffic on Main Street.

• Big Bird operating a motor vehicle in an unsafe manner.

• Angry Birds laughing and giggling uncontrollably and appearing to be happy.

• Tweety acting as if 10 feet tall and getting into confrontations with cats.

• Or any other birds after midnight with Taco Bell items.

As for the playful riff at the end of the news release, Techar said: "I wasn't going to do it, but we decided to show people that we've got a little bit of a sense of humor."

Who said law enforcement can't have a little fun once in a while?

Large numbers of birds and an increased risk of collisions are to be expected during this season, with or without fermenting berries, Erickson noted. Weather conditions also can temporarily halt bird movement, resulting in what's called migration fallout.

"It's par for the course at this time of year, but some years we have a much bigger, more noticeable fallout than other years, and this year's is pretty impressive," Erickson said.

She said small songbirds pausing in their travels often can be seen foraging for insects on the ground or along roadsides, where they typically can find warmer surface temperatures.

"It's been scary for people to drive when you have a whole collection of little warblers that are flitting right on the road, and people have been hitting a lot of them," Erickson said.

To reduce the risk of bird strikes, she recommends people adorn their windows with stickers, suncatchers, or strings.

"If people don't have that, birds smack into the windows, and the real tragedy with that is that half of the ones that fly off have bad enough wounds that they end up dying from head trauma," Erickson said.

Those birds that overindulge on fermented berries yet avoid windows may experience a different sort of head trauma. But fortunately it's nothing they can't sleep off.