Hundreds of big black birds may roost at the University of New Brunswick nevermore.

A large population of wintering crows could no longer be using their long-time roost at the University of New Brunswick.

For more than a decade, a murder of well over a thousand crows tended to a small wooded section of campus overnight, but the birds seem to be in search of a new roost.

Over the past week, hundreds of crows have been spotted on the rooftop of a downtown Fredericton parking garage.

Hundreds of crows are relocating from their traditional roost and have been spotted on top of a Fredericton parking garage instead. (Charles LeBlanc/Youtube) "They could be in search of some place safer," said Joseph Nocera, an ornithologist at the University of New Brunswick. "It makes you think that something must have changed in their original roost site that made them seek another.

Hundreds of wintering crows come together to roost as a strategy to combat the cold, predators, and starvation.

Joseph Nocera, an ornithologist at the University of New Brunswick, says there could be a number of reasons for crows choosing a new roost. (Shane Fowler/CBC) "Perhaps the lighting has changed. It could be as simple as that," said Nocera. "It could be because great horned owls are now more abundant in their previous site where they had lots of trees and this new site does not."

Why the sudden move?

Whatever the reason, the relocation is probably not a bird-brained move.

The Corvidae family, which includes crows and ravens, is made up of species regarded as some of the smartest birds on the planet.

While the change of venue is odd, their large numbers are not. Nocera said there are tens of thousands of large roosts all across North America.

"The largest ever recorded was in the millions," he said. "This one in comparison, is somewhat small."

During the day crows tend to forage and feed individually. But as the sun sets, a murder of crows is formed as a survival strategy.

"There is safety in numbers," said Nocera. "And if things get really bad weather-wise they're shielded by having other members around."

As the winter sun sets over Fredericton, hundreds of crows can be seen circling the city in preparation for roosting. (Shane Fowler/CBC) Nocera said there's been a lot of research in looking at individuals that come to a roost and have been successful in finding food that day.

"He's the one that in the morning gets followed," said Nocera. "So individuals can access who are the good food finders and who aren't."