The Canadian Armed Forces has slammed the brakes on its downtown Hamilton military training because it worried it was disturbing a nest of falcons.

Helicopters flew low over the Stelco Tower for routine training Tuesday, and were scheduled to continue the exercises Wednesday and Thursday. But the forces got word that a citizen had complained that it caused "some disturbance to a falcon nest in the vicinity of Stelco Tower," said Capt. Jamie Donovan.

"It was determined almost immediately given this new information provided to us by a concerned citizen that we would terminate any further training," he said.

The Canadian Armed Forces were scheduled to do three days of training this week. They ended up doing one because it disturbed a nest of falcons. (Samantha Craggs/CBC)

The nest in question is on a ledge of the next door Sheraton Hotel, where Hamilton's resident falcon couple just hatched four new baby chicks.

The Hamilton Community Peregrine Project streams the lives of the falcons, Lily and Ossie. They laid eggs last year but none hatched. In 2016, they produced one offspring.

In Ontario, falcons are considered a threatened species. The Sheraton has been a falcon nest since at least 1994, said Mike Street, senior monitor with the peregrine project.

Street said the peregrine project didn't complain or even know about the helicopter training. Looking at Tuesday's web cam footage from the time of the flights, he said, the falcons don't seem too stressed.

Hamilton's famous falcon couple had four baby chicks this spring. (falcons.hamiltonnature.org)

"It would have been better had this happened a month ago or two months from now, after the chicks were fledged and gone," he said. "But it doesn't appear to have had any effect at all."

The Ministry of Natural Resources and Forestry marks each new chick with bands so it can keep track of the growth of the species. The baby falcons will mature over the summer, and migrate in August or September.

Donovan said the forces managed to get enough training in on Tuesday to make this week's exercises worthwhile. There will be one helicopter flight Wednesday afternoon, but it's not related to training.