The great blue heron is a large and impressive bird that has become an icon for Vancouver’s Stanley Park. The bird can be seen in the park throughout the year and has nested in trees by the Parks Board office since 2001. On March 20th, 2019, the return of Pacific great blue herons to the Stanley Park heronry was announced. This marks the nineteenth consecutive year in which they have laid their eggs and reared their young there. The return is great news because the heron population is under some stress. The nesting birds can be seen in person or via a webcam.

The Pacific Great Blue Heron

The great blue heron has the scientific name Ardea herodias. It’s found in North, Central, and South America, in the Caribbean, and in the Galapagos Islands. The subspecies found in coastal British Columbia is Ardea herodia fannini. It’s known as the Pacific great blue heron.

There are only minor differences between the different subspecies of the heron, except in the case of a white form of the bird found in Florida and the Caribbean. There is some debate about how this form should be classified. The Pacific great blue heron looks much like the other subspecies but is a little smaller.

In southwestern British Columbia, the heron doesn’t migrate. The winters here are mild enough for the bird to stay in the area all year, though we sometimes get snow that soon disappears. I quite often see a heron in a creek near my home during the non-breeding season. The one in the photo below had decided to leave the creek and perch on a street lamp, a behaviour that I’ve never seen before. There was snow on the ground at the time.

Physical Features of the Bird

When their neck is extended instead of curved, the adult herons are generally a little over a metre tall. Males are slightly bigger than females. The birds are predominantly blue-grey in colour with areas of white, brown, and black in various places on their body. Black and brown “shoulder patches” are often visible. The birds have a long and thin bill, tall, stilt-like legs, and long and slender toes. The toes are able to curl around a perch.

The irises of the birds’ eyes are yellow. The herons have a black stripe above each eye that continues as a plume behind their head.  The crown of the head and the face are white. The lower bill is orange and the upper one is grey, at least during the non-breeding season.

During the breeding season, the bird’s appearance changes slightly. The upper bill becomes orange and the bird’s body develops long plumes. In addition, the body is not as grey as at other times of the year and show hues of other colours. These features can be seen in the photo under the first paragraph of this post and in the last photo. The other photos show birds in non-breeding plumage.

Diet

Great blue herons eat fish, as the photo above demonstrates. In fact, small fish are the bird’s main food. The heron also eats shellfish, amphibians—especially frogs—reptiles, small mammals such as rodents, small birds, and insects. It generally hunts alone, though adults and juveniles may sometimes be seen near each other in a good feeding area. In the Greater Vancouver area, the bird finds food in freshwater, in intertidal areas, and in shallow seawater. It also catches prey on grasslands and in agricultural fields.

The bird can be patient when watching for the best moment to attack its prey. I often see a heron moving slowly through shallow water, pausing as it fixes an eye on a particular spot in the water, staying motionless for a while, and finally striking at the prey.

Reproduction

The birds choose a new partner each year. Great blue herons have interesting courtship and pair-bonding displays in which the birds snap their bill, tap their partner’s bill, erect their plumes, and perform other ritualized behaviours. They produce a clattering sound by snapping the tips of their bill together in a rapid sequence. The birds aren’t very vocal during most of the year but produce squawks, clucks, and other sounds in their heronry.

The male generally collects the materials needed to refurbish a nest used by herons in a previous year. The female uses the materials to make repairs. The pair build a new nest if necessary, however. The herons usually nest in a tree and in large groups but occasionally build their nest on the ground or in another location.

The females lay from two to six eggs, which are blue. Incubation takes four weeks. Both the males and the females incubate the eggs. According to the Stanley Park Ecology Society, the male normally incubates the eggs during the day and the female incubates them at night.

The parents regurgitate food to feed the chicks. Unfortunately, one or more of the chicks often dies due to rivalry between the siblings. A chick may die from starvation because its more dominant siblings are fed more often.  Sometimes a dominant chick attacks a more submissive one or even pushes it out of the nest. The surviving youngsters leave the nest when they are eight weeks old and follow their parents to the feeding grounds.

Some great blue herons have reportedly lived for as long as seventeen or even eighteen years. Most probably live for a much shorter time. If they survive the juvenile stage, they may have a lifespan of around ten years.

Population Status of the Pacific Great Blue Heron

The Pacific blue heron population is classified as vulnerable in British Columbia. Most of the birds live in the southwest region of the province. Here they are sometimes disturbed by humans and are losing some of their traditional habitat and nesting areas. Another problem is that the nests are subject to predation by bald eagles, whose population in increasing. The success of the heronry in Stanley Park is important.

The Heronry in the Park

Historical reports from as early as 1921 mention the herons nesting in various areas of Stanley Park. Ever since 2001, however, they have chosen to produce their young in the trees by the Parks Office. The fact that the public watches their activities doesn’t seem to bother the birds.

The location of the heronry is somewhat surprising. The surrounding area is quite busy due to human activity. The location is near tennis courts and a road. Herons are usually disturbed by noise, but the Stanley Park ones seem to tolerate it without concern.

The parks board has taken steps to protect birds. The trees where they nest are surrounded by fences, which also protect people from falling sticks and guano. The birds sometimes come to the ground in these protected areas. Metal guards around the tree trunks prevent raccoons from attacking the nests.

Viewing the Heronry in Person or Online

Those of us who live in or near Vancouver can go to Stanley Park and watch the herons. (Binoculars are very useful for this purpose.) The Parks Board office is located at 2099 Beach Avenue. If you don’t live near Stanley Park, you can still look at the heronry. The city of Vancouver has placed a webcam by the nests.

I’ve included a link to the webpage that gives access to the camera in the “References” section below. Brief instructions are included on the page. You can take control of the camera for one minute if you wish, aiming it at the birds and the nest of your choice. It’s possible to “line up” if someone has control of the camera before you. Colour-coded buttons let you know when it’s your turn.

The resolution of the picture provided by the webcam is not great, but it’s still enjoyable to see the herons. An overall view of the heronry gives an idea of how many birds are using the trees as they fly by the camera. It’s necessary to zoom in to see the birds on their nests.  A list of nests lets you choose one to see.

You can get a close-up view of the herons without controlling the camera yourself when someone else is using it. I’ve found that I can control the camera on my Windows laptop, but on my iPad I’m limited to views that other people have chosen.

The webcam has been used in previous years and hasn’t disturbed the birds. Watching  the herons with the camera is fun as well as informative. Spring is a great time of year for heron lovers and a very important season for the birds.

References

• Facts about the great blue heron from Hinterland’s Who’s Who, Canadian Wildlife Federation
• Information about great blue herons from the Cornell Lab of Ornithology
• A description of Pacific great blue herons and the heronry in Stanley Park from the Stanley Park Ecology Society
• Brief instructions for using the heron cam and a link to the camera from the City of Vancouver website