Since Mr. Bull first saw the birds and then went on to discover their first nests in a huge fir tree in Bridgeport, many people have had similar experiences. Still, as the rest of us shiver in the cold, it's worth wondering what wild parakeets are doing up and down the Connecticut shore and how they manage to survive when the temperatures dip down around the single digits as they did this week.

Why they're here is the subject of multiple urban legends, all vaguely plausible, none, unfortunately, with any known basis in fact. The most common include an accidentally opened crate at Kennedy Airport or an accident on Interstate 95 and an overturned truck on its way to a pet store. Mr. Bull thinks it's more likely that some pet owners got sick of the squawking and released the birds, and nature took its course.

But what is true is that Westport and Bridgeport, Fairfield and Greenwich, Stamford and Madison and most towns nearby are home to a sturdy cadre of monk parakeets, who, it turns out, get through the winters just fine.

The birds are about 12 inches long and green with a gray forehead that gives them a monklike visage and gray scaling on the breast. They come from southern South America, particularly Argentina, environs with serious winters and a climate range not that different from our own. They are nonmigratory, very noisy and gregarious, and build huge nests with multiple chambers, where they can hide out and keep warm during severe cold snaps. And they're hardy enough that populations have been found as far north as Quebec, and there are colonies in the United States from Florida and Texas to California and New York. Since they tend not to travel far, bird experts say, it's almost certain that each of the colonies began independently.

There are perhaps 1,000 of the parakeets in Connecticut, though no one knows for sure, enough to cause problems for utility lineman trying to remove their huge nests from utility poles, for city officials in Stamford trying to keep them off of light stanchions at ball parks and for the students at the University of Bridgeport trying to get some sleep despite the screeching birds in the white pines outside their dorms.