Park officials have closed climbing routes on a popular rock wall near Squamish, B.C., so that climbers stay clear of a peregrine falcon nest.

Sections of two routes — Planet Caravan and Warriors of the Wasteland — on the Stawamus Chief are expected to be closed until mid-July.

That's when the falcon chicks are likely to fly off.

Peregrine falcons are only the size of crows, but they're territorial and can get agitated, said Joanna Hirner, a conservation specialist with B.C. Parks.

"If people do get close to a nest site, the falcons typically will make noise and dive-bomb them."

Cliff-ledge nests

Peregrine falcons are the fastest birds on Earth, capable of reaching speeds of more than 300 km/h during their hunting dives.

Every year, the falcons build nests on cliff ledges called scrapes.

In March, they pick their spot, scraping a small depression in the dirt or sand and laying their eggs.

The falcons incubate in May, and by the next month, their chicks are hatching. The chicks usually fly the nest sometime in July.

A pair of peregrine falcons usually build a nest on the Stawamus Chief every year, says B.C. Parks. (Martin Diotte/CBC)

Climbers often tip off park officials to the nest spots, Hirner said.

"We do monitoring on the ground with spotting scopes and binoculars. But we're quite far away and these birds are quite small."

Park officials say if you encounter a falcon, keep your distance. If it appears agitated, leave the area as soon as possible.

If you want to catch a glimpse of them from afar, make a stop on the west side of the Sea-to-Sky Highway at the portion directly facing the Grand Wall of the Stawamus Chief, Hirner suggested.