The sudden death of more than 4,000 red-winged blackbirds in the southern United States won't affect breeding in New Brunswick, according to a wildlife expert.

A worker collects dead birds from the backyard of a home in Beebe, Ark., on Sunday. (Stephen B. Thornton/Arkansas Democrat-Gazette/Associated Press)Tony Diamond, a research professor in wildlife ecology at the University of New Brunswick, was reacting to the situation in a small town in Arkansas, where more than 4,000 red-winged blackbirds dropped dead out of the sky on New Year's Eve, littering cars, homes and lawns.

Another 500 birds dropped out of the sky in Louisiana, falling onto a stretch of highway this week near Baton Rouge.

The red-winged black birds commonly breed in New Brunswick during the summer and then migrate elsewhere during the winter.

Diamond said it's unlikely the deaths will have a ripple effect on the breeding in New Brunswick.

"It's a very widespread species, the red-winged blackbird. And although we do have them commonly breeding here, they breed commonly in wetlands across North America," Diamond said.

"So there might have been one bird from our area in that flock and we certainly wouldn't notice that."

Diamond said mass deaths of birds aren't common.

"It's very unusual for such a large number of birds to drop dead in such a small area and it would make me suspect unnatural causes," he said.

Red-winged blackbirds breed in New Brunswick during the summer and then migrate elsewhere during the winter (David Zalubowski/Associated Press)Preliminary autopsies performed on some of the birds found they had a mass mid-air collision. There is no word on the cause.

Jim Wilson, an active birder and naturalist in Hampton, said he couldn't believe the images on the internet showing thousands of red-winged black birds scattered on roads.

"You know, it's very sad to see. Everything is linked," Wilson said.

Red-winged blackbirds are among the most abundant birds in North America, with a population estimated at 100 million to 200 million.