If birds that feed on winter berries in the Northern Hemisphere seem to be painting the town red, it could be because they're intoxicated.

Alcohol forms in berries as they ferment with the first frosts, and the birds that gorge on these winter fruits may get drunk more often than we think, scientists say. (See National Geographic's backyard bird identifier.)

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

Such was the case with several Bohemian waxwings (Bombycilla garrulus) that flew into Whitehorse, Yukon,