Pacific great blue herons return to nest in Stanley Park

The heron cam at Vancouver's Stanley Park is buzzing with activity as the park's majestic Pacific great blue herons have come back to nest for the summer.

The birds have claimed nests in their chosen spot above the parking lot at 2099 Beach Avenue. This year. the herons arrived March 11, three weeks later than last year.

Greg Hart, a biologist with the Stanley Park Ecological Society, says that's largely due to the colder weather.

"Rather than getting cold, wasting energy and standing around their snowy nests, they went off to their foraging grounds to get food and help stay warm," he said.

The birds typically stay until July, the end of breeding season.

Hart says the birds have been flocking to the site in Stanley Park since 2001, and the nests make up one of North America's largest urban Pacific great blue heron colonies.

"It's unique in that they usually don't tolerate human disturbance terribly often, so getting a colony that's this big and this large in a metropolitan area is extremely rare," he said.

The nests are especially important because of conservation concerns. Hart says because the birds like living where humans do — like the highly populated Fraser Valley — their nesting areas are vulnerable to human encroachment and development. 

The area around the Salish Sea is home to around 3,000 herons and the largest concentration is around the Fraser River delta. There are around 4,000 to 5,000 herons in Canada which make up almost half the global population.