A Pacific Great Blue Heron eyes a CTV News camera in Vancouver's Stanley Park on Thursday, Aug. 24, 2017.

Bird watchers are flocking to Stanley Park to welcome the Pacific Great Blue Herons who have made their triumphant return to the city.

This is the 20th consecutive year the herons have been nesting in Vancouver's largest park. The first few returned Feb. 21 to a colony near the Vancouver park board office on Beach Avenue.

According to the City of Vancouver, the area is one of North America's largest urban heron colonies. The park board estimates there were 82 active nests last year, with 112 fledglings raised.

"The number of active nests and fledglings raised last year is consistent with previous years indicating the nesting site is favourable to the herons' breeding success," board chair Camil Dumont said in a news release.

The park board is offering birders a chance to get a closer glimpse of all the action with its "Heron Cam." The live-stream offers a birds-eye view of 40 nests, which is available until the end of breeding season in August. Viewers are also able to take control of the camera and zoom in on multiple nests, giving them different vantage points to capture the herons as they grow over the next six months.

"The Pacific Great Blue Heron is unique because it does not migrate," the park board said. "Their natural year-round habitat is the Fraser River delta which is under pressure from urban development, resulting in the loss of feeding and breeding grounds."

In 2018 the first eggs were seen on March 29, the first hatchlings were captured on April 28 and juveniles started "flight test" exercises in mid-June.

According to the park board, eagles remain the biggest threat to the heron colonies, but there were fewer attacks recorded last year compared to the previous year.