By Jeanette Rive
“Is that a loon?” a curious lady asked as we were admiring a heron at the Patterson Creek bridge last year. I identified the heron for her and said she probably wouldn’t find a loon along the Rideau Canal, although they have been seen at Dow’s Lake in the spring. I gave her a few pointers on what to look for to identify the equally impressive loon.
Along the canal and other local waterways, especially in ponds and inlets where the water is shallower, we are often treated to a close-up view of the Great Blue Heron. It doesn’t matter how often I’ve seen it, I don’t seem to be able to resist pausing and appreciating this majestic bird living among us urbanites.
Several herons call the Ottawa area home: the Black Crowned Night Heron, frequently seen in the Britannia area; the Green Heron, also seen in Britannia and other outlying areas; and the Great Blue Heron, the largest of them all.
GBHs, as they are commonly known, have a wingspan of almost two metres. Males are slightly larger than females but there are no other significant differences between them. They can live for up to 17 years.
How much do you think a GBH weighs? Four kilos? Three kilos? They weigh a mere two kilos or so! It’s about half the weight of the average Canada goose.
Unlike humans, whose bones are solid, birds have very dense but hollow or semi-hollow bones to make flying easier. Their bones are also what is called pneumatic: looking a bit like honeycomb, they are full of air sacs that provide a continuous flow of breath throughout their bodies. You can recognize a heron in flight because they hold their neck in an S shape, head tucked back and their legs straight out behind them.
A heron is a very patient bird. It will stare intently at the water, either standing stock still or moving very slowly. Suddenly it will strike its prey at the speed of lightning, grabbing a small amphibian or a fish or spearing a larger fish. It can manipulate a large fish by turning it around either in the air or on the ground so it can be swallowed head first all in one go. They can eat up to half a kilo of food each day.
Even though they tend to nest in colonies, which can range from two to 100 nests, GBHs are solitary when feeding and foraging and can be territorial. I have seen a heron walk across Brewer Pond very slowly and suddenly flush and chase away another unwary heron to the Rideau River.
Herons make their nests in trees, often at the top of dead trees. The male returns to the same nest every year, hoping to lure a female to join him by calling loudly and displaying. When a female has agreed to the proposal, he will present her with sticks and nesting material to build or renovate the nest, which can be up to a metre wide. Between two and six eggs are laid. Incubation lasts about four weeks – the male incubates during the day, the female at night. The parents share the feeding duties, rarely leaving the chicks alone for the first few weeks. If a chick falls out of the nest, it is abandoned. The parents only feed a chick when in the nest; they must return to the nest to be fed. By about the 45th day, the young weigh about 85 per cent of adult weight. They fledge and leave the nest at about 10 weeks.
The Great Blue Heron is the most widely distributed heron in Canada; scientists estimate there are probably tens of thousands across the country. We are privileged to be able to see them so close to home.
Jeanette Rive is a Glebe bird enthusiast and photographer and a Glebe Report proofreader.