The Return of the Great Blue Herons
A little late this year, but the Great Blue Herons have returned to the Stanley Park/West End rookery. This will be the 20th year that the herons have chosen a small section of park, just behind the Vancouver Parks Board offices to raise their young. Their nests straddle the divide between the densely human populated West End and the wild urban wilderness of Stanley Park; the herons are both citizens of the towers and gatekeepers to the rainforest.
Nest Construction
High above the ground, perched in three species of trees (red oak, broadleaf maple, London plane), the herons have started to construct their twig cradles for their soon to be arriving offspring. While some will start from scratch and take a week or more to build their nests, others (the lazy ones) will refurbish an existing nest that has survived from the previous spring. This process of nest building is done almost entirely by the male herons who arrive at the park before the females, to start the construction process.
Once a male has built an adequate nest, he begins to court the tardy females. He does this by fluffing the plumage on his neck, doing aerial circles of his nest and waving thin branches in hopes of attracting the attention of a potential mate. Herons do not mate for life, so each spring they need to re-enter the dating pool.
Species at Risk
The location of the rookery has helped the Great Blue Heron population rebound to record numbers. Established in 2001, the herons moved from Beaver Lake to their more urban setting. Their new location is far less susceptible to eagle raids, as the eagles are less likely to look for food near human populated areas. For this reason, the survival rate of the hatchlings has risen dramatically.
The current rookery is now considered the largest known ‘urban’ rookery in North America with 82 active nests in 2019. The Parks Board has also played a part in the surging survival rate by adding predator guards at the bottom of the nesting trees to stop mink and raccoons from climbing the trees in search of a lofty meal.
Learning to Fly
Over the next week, the females will lay a clutch of eggs. It will take a month or so for the eggs to hatch, with hatchlings potentially emerging this year in mid-to-late April. Vancouverites can follow the progress of the young on the heron cams setup by the Parks Board. Positioned on the apartment towers adjacent to the rookery, the cameras allow for an up close view of the babies development.
During the incubation period, both adults will share nesting duty. The male herons tend to take the day shift and the females the night watch. Once the hatchlings arrive, both adults will also share food-procuring obligations in a 10km radius from the nests. They will return to the colony and regenerate their spoils to the young. Yummm…. leftovers.
Two months after they have hatched, the young herons will leave the nests and follow their parents to the shorelines for hunting instruction and survival tips. They will be fully independent by June or July, with the last ones leaving the colony by August.
For more info on the Great Blue Heron rookery in Stanley Park, visit the Stanley Park Ecology website. Locals can assist the Park Board in their monitoring of the heron population by adopting a nest. Efforts like these will help ensure the thin-legged sentry’s of Stanley Park return for years to come.
Vancouver Bike Tour
To view the Great Blue Herons and their rookery, join us for a Stanley Park bike tour everyday starting at 9:30AM from English Bay Bike Rentals.
