Bird watchers don't have to leave home to take in the annual return of a massive heron colony to Vancouver's Stanley Park.

A livestream operated by the city's park board is active for the fourth season in a row, providing viewers with a close-up look at the nests of Pacific great blue herons.

The tree-mounted cameras are turned on each year at the spot where the large birds have hatched their young for 18 years. For a few months each year, the colony takes over the treetops across from the tennis courts and above the parking lot at 2099 Beach Ave.

The herons have been using the spot near the park board office since 2001, but have been known to nest at various locations in Stanley Park since 1921.

On Thursday, the park board announced that the cameras are back on, this time in high-definition. There are also new features this season. Overnight, when the camera is dark, the board will instead feature a time lapse of the day's activity.

Viewers can also take control of the camera for two minutes at a time by clicking the "Control" icon on the bottom right-hand camera when the livestream is in full screen mode. They'll be able to see how many people are waiting ahead of them and a countdown to when it will be their turn to take over.

In the top right corner, they can choose which of the 11 views they'd like to watch. There is also a "snapshot" option to take a still image of the video feed

The Stanley Park Ecology Society will also be hosting live Facebook events from mid-March to the end of the summer, when the herons move on. The question-and-answer sessions will be held at key times for the colony, including hatching of the first chicks.

For those who visit the site in person, the SPES will have a biologist on-hand to answer any questions they might have.
 

Vancouver herons

More than 100,000 viewers have watched the birds nest, lay eggs, care for chicks and fend off eagle attacks in the four seasons the "Heron Cam" has been in operation, the park board said.

The board has several initiatives in place to protect the species, including restrictions on construction at the Stanley Park Brewery site and bands around the bases of trees to keep predators from climbing up. 

Visitors are asked to avoid anything that could distress the birds, including loud noises, bright lights and balloons and kites.

Last year, the colony built 84 active nests and raised approximately 72 fledglings. The 2017 season saw an increase in eagle attacks, the SPES said.

Stanley Park hosts one of the largest urban great blue heron colonies in North America, providing homes to dozens of the species considered at risk in Canada. About a third of the world's great blue herons live around the Salish Sea.

Great blue herons have a wingspan of about two metres and a height of around 60 centimetres, but only weigh five to six pounds due to their hallow bones. Their typical flight speed is 40 km/h, but they can move as quickly as 55 km/h, the SPES says.

They can live up to 18 years but typically have a lifespan of about a decade.

Some prefer to nest alone, but colonies can contain as many as several hundred pairs.
 

Vancouver herons