Pacific Great Blue Heron
(Ardea Herodias fannini)
Whether overhead in flight or wading in the shallows at the edge of the lake, the sight of a Great Blue Heron causes us to pause and observe quietly… or run for a camera. Tall, slender, serene and looking totally in control, this bird elicits our admiration. This page provides information about its characteristics, habits, and population numbers along with visuals and videos, which we hope will add to your appreciation of this inhabitant of Hotel Lake.
In First Nations culture, the Great Blue Heron is considered a good omen and represents grace, purity and patience. In legends, it is portrayed as self-reliant and determined and appears as a watchman over orca communities. Often portrayed in indigenous art, the example below can be seen on the side of the Coast Salish Heron, a ferry sailing between Tsawwassen and the southern Gulf Islands.
Of all herons in Canada, the Great Blue Heron has the widest distribution, ranging from the Maritime provinces across southern Canada to the Pacific Ocean. As shown in the map, the yellow area represents locations where herons migrate south starting in mid-September. Banded birds from Canada have been found in Mexico, Honduras, and Cuba. Great Blue Herons begin their return flight in April and typically return to the same nesting site year after year.
The subspecies fannini of the Great Blue Heron is referred to as the Pacific Great Blue Heron. About 4000-5000 Pacific Great Blue Herons (of the 9500 to 11000 global population) are found year round in British Columbia along the coastline from the lower mainland to Alaska. It is about this subspecies, referred to as PGBH, that we dedicate this webpage.
Standing tall, this adult heron is well over 1 meter tall and weighs around 2.5 kg. Comparatively, it’s the height of a grade 3 student and the weight of a newborn baby. What you see is a tall thin bird with long legs, neck, bill and wings.
The top of the head is white with a black strip on either side extending from the yellow eyes to the black plumes at the back of the head. Its back is a subtle blue grey colour and the breast is white with dark streaks. The upper side of the wing is two toned with the flight feathers at the edge of the wings being deeper in colour. During breeding seasons, this bird displays brighter feathers and long plumes on its breast, flank and back. Males and females look very similar with the exception that the male is slightly larger.
Beautiful in flight, this long limbed bird moves through the sky with deep, slow wing beats. Light in weight and with a wingspan that can exceed six feet, this heron seems to lift off the ground as if gravity didn’t exist. In flight, the heron’s neck is doubled back so that the head is closer to the body, and the legs are. stretched out straight behind. In full fight, it can reach 30 miles per hour.
Calls and Sounds
We often think of the Great Blue Heron as the tall, silent type but this bird does make a variety of sounds. During a courtship display a male will make loud bill snaps and finish with a “gooo” call. As if to alert its mate that it is inbound, herons will make a “roh-roh-roh” sound when approaching the nest. When alarmed in the colony, it gives a “frawnk” sound. You may hear clucks when it forages and an “eeee” call when in flight. As well, mated pairs “clapper”; rapidly side to side tap their bill tips.
Listen to these calls and sounds at:https://www.allaboutbirds.org/guide/Great_Blue_Heron/sounds
The Great Blue Heron is a carnivore; its diet is largely animals. Its main food is small fish but it also eats shellfish, insects, rodents, amphibians (mostly frogs), reptiles and small birds. The Great Blue Heron, as it stands motionless in the shallows, will basically eat anything that moves that it can swallow.
Herons are renowned for their patience and their skill when fishing. Truly, the small fish don’t have much of a chance considering that they don’t identify the two motionless sticks in front of them as the predator’s legs and they don’t notice the sky-blue belly of the the Great Blue Heron above them. Only the heron’s head and eyes move and detect the small fish that unsuspectingly swims too close. With amazing speed, the heron’s head plunges into the water and the fish is impaled (“bill-stabbed”) or caught in its beak. The heron’s head comes out of the water and with a quick movement the whole small fish is heading down its gullet. In the same way about a pound of fish is caught each day.
Nesting and Courtship
Between February and April, most Pacific Great Blue Herons gather in colonies where they court, nest, and raise young. The male chooses a nesting site which may involve building a new nest or improving an already existing one. He looks for a nest site close to water and foraging grounds and away from humans and predators. Preferred nest sites are often in tall trees 20 to 30 m off the ground, and frequently where there are nests from former years. Once the location is set, the male puts on energetic displays and shrieks loudly to attract a female.
The courtship display pictured above is impressive, but the male is “not just a pretty face”. After he has chosen the ideal nesting location and attracted a female, he brings twigs to give to the female for building the nest. Usually, nests are about 1 m in diameter and have a central cavity 10 cm deep with a diameter of 30 cm. The herons sometimes line this internal cavity with twigs, moss, lichens, or conifer needles. Once the 3 to 5 eggs are laid, the male generally takes the day shift for 28 days incubating the eggs. Once the eggs hatch, he and the female spend the next three weeks warming (brooding) the young, feeding them with regurgitated food and guarding them so that the nest is never left without one adult. PGBH take, on average, 95 days to complete a nesting cycle.
Once hatched, young PGBHs develop rapidly. Competition for food makes feeding time a raucous affair. Often only the strongest survive. Falling or being pushed out of the nest is a fatal happening as the parents will not feed young outside the nest. At 8 weeks the young birds attempt to fly clumsily from one tree to another but return to the nest to be fed. At around 10 weeks the young become independent. Fewer than 25% of juveniles survive to their second year. PGBH mate at 2 years old and choose a new mate every breeding season. Great Blue Herons live long lives, some as long as 17 years.
Threats and Predators
Great Blue Herons are particularly sensitive to human disturbance. The noise and activity of humans as far away as 200 metres from a colony can cause birds to abandon nests. This leaves eggs and nestlings unguarded and vulnerable to predators.
In addition, most of B.C.’s human population live in the heron’s favourite areas – the coast and the southern interior. Land clearing, marsh draining and urban development in these regions is limiting the number of available nesting sites and foraging areas. The human threat is twofold: disturbance that interrupts the reproduction cycle and habitat loss.
The predator most likely to attack a heron nest or to take advantage of an unguarded nest is the bald eagle. Predation and the associated disturbance eagles cause result in significantly higher nest and colony abandonment. Although bald eagle numbers were in serious decline, there has been a robust resurgence in their numbers mainly attributed to a 1972 ban on the pesticide DDT. Eagle populations on the south coast have increased since the mid-1980s and the rate of attacks on nesting herons has more than doubled over the same time period (Vennesland and Butler 2004).
Population Numbers….how are Pacific Great Blue Herons doing?
Ross Vennesland, a Senior Species at Risk Biologist with Environment and Climate Change Canada, Pacific Region, very kindly provided several information sources for this article. Having studied herons since the 1990s, he is quoted in 2010 as saying, “bird counts indicate the population of Pacific Great Blue Herons is in a slow decline, and fewer than 10,000 remain around the “Salish Sea,” a name applied to the inland waterways of Washington and B.C. For reasons that aren’t clear the average number of surviving young herons produced per nest each year has dropped from about two in the 1980s to about one now – a level that might be near the minimum needed to sustain the species.”
Because of the Great Blue Heron’s sensitivity to human activity and its declining population, it has been placed on B.C.’s Blue List of vulnerable species.
The Pacific Great Blue Heron was assessed as Special Concern in 1997 and again in 2008 by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) due to a small population size, declining productivity, threats related to Bald Eagle predation, habitat loss, and human disturbance. The species was listed on Schedule 1 of the Species at Risk Act (SARA) in 2010.
The Sunshine Coast has seen a strong decline in nesting population size.(COSEWIC 2008; Chatwin pers. comm. 2014).
In the 1970s and 1980s, the Sunshine Coast had 2 colonies, with 44 pairs near Sechelt and 94 pairs in Pender Harbour (Butler 1997).
These colonies were abandoned after disturbances and relocated colonies have not been found despite repeated searches. (Source: Status and Conservation Stewardship of the Pacific great Blue heron in Canada -Butler and Baudin 1999)
Great Blue Herons, their nests and their eggs are all protected by the British Columbia Wildlife Act and by the federal Migratory Birds Convention Act. Their nest trees are also protected year round, on both public and private land. “Wildlife at Risk” Great Blue Heron - Gov.bc.ca
How can we help the Pacific Great Blue Heron?
1. Herons compete with people for space. Being aware of their presence along the shorelines of fresh or salt water and protecting adequate feeding habitat and nesting space is helpful.
2. Reducing disturbances at nesting sites is especially important at the early stages of nesting. Scientists suggest that, as a general rule, there should be no development within 300 m of the edge of a heron colony and no disturbance in or near nests from March to August.
Unusual events and loud noises such as mechanical chippers, chainsaws, and large trucks may cause the herons to abandon their nests.
3. Protecting large trees near water can help herons find perches and may provide the site for a future nest or colony.
4. You can help scientists and officials alike make informed decisions by providing your bird observations. Upload your photo with location to iNaturalist.ca and scientists will incorporate your data.
It is not common, but occasionally herons choose a nesting site and become tolerant of people. Herons have been nesting in Vancouver’s busy Stanley Park for over 75 years. You can watch live camera footage of a heron nest in Stanley Park and also see archived footage from previous years by going to: “Watch the Pacific Great Blue Heron Live from Stanley Park”
Information for this page is drawn, in part, from the Canadian Wildlife Federation, Hinterland Who’s Who, and the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and from the following references.
Canadian Wildlife Federation, Hinterland Who’s Who, about Herons
Committee on the Status of Endangered Wildlife in Canada (COSEWIC), report on Blue Heron
Committee on the Status of Endangered Wildlife, Canada, 2008 status report on Blue Heron
Great Blue Heron (Ardea herodias fannini) (canada.ca)
South Coast Conservation Program website on coastal herons
Great Blue Heron fannini ssp. |
Birdfact.com, an excellent resource on Blue Herons
Federal management plan:
Great Blue Heron fannini subspecies (Ardea herodias fannini) (canada.ca)
Provincial management guidelines (for things like land development)
Atlas of Heron Nesting Locations (note that zero nests are documented in Garden Bay Area)
British Columbia Great Blue Herons Atlas (cmnmaps.ca)