For Ottawa ornithophobes, murder of crows like something out of Hitchcock

Thousands of crows have descended on the capital, gathering in trees and filling the air with a cacophony of cawing in a daily ritual that's giving some residents the creeps. 

Experts say the birds are merely meeting up for nightly roosts, an avian slumber party that actually occurs each winter.

Nevertheless, some people witnessing the phenomenon for the first time are surprised and — in some cases — downright frightened.

Many are using social media to document the strange sight, and look for answers.

Crows 'not going to eat you'

Bird expert Bruce Di Labio says there's nothing to be worried about, and points out the spectacle has been going on for as long as there have been crows.

"Enjoy it," Di Labio advises. "They're not going to eat you. They have no interest in people in the big picture. They are just getting ready to roost for the evening."

Di Labio said American crows generally start gathering like this in late fall. As many as 10,000 have been counted mustering in one location in Ottawa, he said.

Di Labio said crows gather for security: the greater their number, the lower the chance of falling prey to a predator such as the great horned owl.

"There is safety in numbers," said Di Labio.

Hospital popular roosting site

One of the longest-standing roost sites in the capital is around the Ottawa Hospital's General campus on Smyth Road. 

"A lot of people don't like crows, but they're part of nature and to just watch their behaviour is always fascinating, he said. "It's kind of neat just to watch them come in to roost, listening to them calling and interacting. It's something I'm surprised more people don't go out towards dusk and just watch it."

The crows tend to head west in the early morning toward Richmond and Carp where there's an abundance of agricultural land because they like to feed on leftover corn, Di Labio said. Some prefer searching for grub at the Trail Road landfill. 

Mid-afternoon, the crows return east to roost for the evening. 

"We don't have it bad," said Di Labio, who pointed out that some roosting sites in the U.S. have been known to host murders in the millions.

If you still can't stand the sight and sound of the noisy creatures, you'll have to wait until the early spring to rest easy — that's when they scatter to their own territory until it's time to meet up again next fall.