The Upper/Lower Village Connector Trail in Wessex Ravine Park is located near a Pacific Great Blue Heron nesting colony. With well over 100 nests, this colony is the largest known on Vancouver Island. When nesting, these striking birds can be very sensitive to disturbance, so it is important to be a good neighbour – please use the stairs and trail quietly and with care.

Heron nests in the treetops near Wessex Ravine Park. Photo: Danielle Lacasse - Madrone Environmental

Pacific Great Blue Herons

These Pacific Great Blue Herons disperse to salt and fresh water habitats throughout the local watersheds over the fall and winter, feeding on fish, amphibians, and other small creatures in shallow waters and open fields. However, for the nesting season they prefer to gather together in colonies. You may see them at the colony as early as January, scouting out their nesting sites and gathering sticks to repair or build new nests. Throughout the spring and summer, they incubate and raise their young until as late as September.

Pacific Great Blue Herons are a provincially and federally listed endangered species, and declining in population. Successful chick-rearing in this colony is important for the wellbeing of the species in the Cowichan Valley.

An adult heron on a nest. Photo: Danielle Lacasse - Madrone Environmental

Sensitivity to Disturbance

Herons typically establish their colonies close to areas with abundant food. This colony has chosen to nest near the rich habitat of the Cowichan Estuary.  However, areas with abundant food sources can sometimes overlap with human development, and given that these large birds require just the right conditions to nest (e.g., suitable structures in trees, proximity to food source, etc.), it may be that they compromise for areas near human activity. While this particular colony may be somewhat adapted to humans, as it is near homes, yards, and roads, they are still sensitive to loud, sudden disturbances from human activity. They may temporarily leave their nests (called ‘flushing’), which can cause a stress-response, as well as expose eggs and chicks to predators such as eagles. In some cases, if disturbed, heron parents may abandon their nests, eggs or chicks entirely. In other cases, an entire colony may abandon a nesting area. Such responses can reduce the number of chicks successfully reared to adulthood.

Some of the risk factors for heron disturbance by people include loud voices or noises, fast movements (such as running), large groups of people, the presence of pets such as dogs, and proximity to the nests.

Herons may be particularly sensitive to disturbance early in the nesting season while they are building nests (January – April).

Signs of Disturbance

Herons may exhibit certain behaviours when they are becoming concerned or stressed about a potential threat. They might stare intently at the threat or make loud “chortle/clucking” noises. If sufficiently concerned, they will flush, flying away from the nests in small or large groups.

Using the trail/stairs as a Good Neighbour

Use the trail/stairs quietly, and stay on the trail. Keep your voice low when near the colony area. Use the stairs for walking between the upper and lower village area only, and refrain from running. Do not carry or wheel large items such as bicycles down the stairs. Avoid using the area in large groups. Make sure your pets are on a leash and under control.

If you see concerning behavior indicating the herons may be in distress at the colony in response to public use of the trail/stairs, call the CVRD at 250.746.2660, or 1.855.781.9524 for urgent after-hours issues.

Want to learn more about these fascinating birds? 

The Cowichan Estuary Nature Centre is located in Hecate Park, a short distance from the colony and Wessex Ravine Park. The Nature Centre offers programs and activities for visitors of all ages to learn about the nearby estuary and the wildlife that live there, including the herons. You are likely to see the herons feeding in the estuary there as well, especially at low tide. You will also find interpretive signage about the herons and the estuary along the trail at Hecate Park.

The Cowichan Estuary Nature Centre also has a webpage with more information about Pacific Great Blue Herons. Check out and operate the Nature Centre’s Heron Cam from their webpage!  The Heron Cam is located on top of a 68’ high tower in Wessex Ravine Park, and offers a ‘birds-eye’ view of the nearby heron nesting activity. That is the best ‘good neighbour’ way to observe the next generation of herons being raised from egg to adulthood by their watchful and attentive parents.