A disgruntled red-winged blackbird has taken up a roost at Maison Radio-Canada in Montreal, and it is not being very neighbourly.

In fact, the bird has dive-bombed anyone and anything in sight since establishing its nest somewhere on the property.

It's gotten to the point that SNC-Lavalin, the managers of the building, have had to put out a sign warning pedestrians to keep an eye on the bird or risk being threatened.

"It's not a permanent solution, but we've put out a sign and had someone out there telling people to be careful," said Jean-Michel Champagne, environmental specialist for SNC-Lavalin.

Champagne said it all started sometime last week when a baby bird belonging to the red-winged blackbird couple fell out of its nest somewhere near the entrance. The male of the couple, which can easily be spotted with the bold red and yellow patch on its wing, went into a frenzy and began dive-bombing anyone who approached.

Champagne says the bird sent everyone into a panic, and people had to hurry to get out of range of the bird.

"We've never had people hurt themselves, but this year, an employee was injured running away," said Champagne.

According to Barbara Frei, the director of the McGill Bird Observatory, male red-winged blackbirds take up a territory and will defend it without caution.

Frei is currently doing her postdoctoral research at McGill and the University of Ottawa. She has a particular fondness for the red-winged blackbird. Her first work in the field was to check red-winged blackbird nests.

"It really depends on the individual," said Frei. "I knew when I checked the nest of one particular male, I'd have to wear a bike helmet."

Frei says that red-winged blackbirds are intelligent and like to take up residence in cedar hedges. She said it's not out of the ordinary to hear of a red-winged blackbird being defensive and said the behaviour should settle down after a couple of weeks.