Grey Heron

Ardea cinera - The Grey Heron

The elegance and grace of the grey heron is undeniable, leaving spectators to admire their poise. Its tall stature and deliberate movements all contribute to its overall image and aesthetic appeal. This is a particularly tall bird, standing at about a metre in height. Its plumage is a beautiful grey on the back and wings, with an off-white underside.

Did you know? When they are in breeding season, the colour of the grey heron’s bill changes from yellow to a brighter orange, and its legs go from a yellow-brown to a rosier shade of pink.

The head is white with a striking black supercilium (feathers that form a stripe) and a thin crest. The beak is a pinkish-yellow and is particularly strong. Juvenile birds have a dull grey head. When it flies, it retracts its head, forming a clear S-shape with its long neck. The wings are bowed. Males and females look very similar to one another.

When they are in breeding season, the colour of the grey heron’s bill changes from yellow to a brighter orange, and its legs go from a yellow-brown to a rosier shade of pink.

Size

Range weight: 1 - 2 kg
Range length: 84 – 102cm
Range wingspan: 155 – 195cm.

Habitat

These are wading birds that favour areas like marshes, dams, lakes, lagoons, rivers and reservoirs. They have actually benefitted from the lifestyle estates and parks that have been built with water features, as these provide a ‘natural’ habitat for the herons.

Distribution

The grey heron can be found throughout South Africa, as well as in many parts of Europe and Asia.

In South Africa, they can be seen on Thesen Island in Knysna, Gillooly’s Farm and President Ridge Bird Sanctuary in Johannesburg, Gonubie Mouth Bird Sanctuary in East London, and Tussen Die Riviere Game Reserve (about two hours’ drive from Bloemfontein) in the Free State.

Diet

This heron is happy to eat whatever fish, crustaceans and other animals it can find in the water in which it wades. Its diet includes various fish species, eels, lizards, worms, small snakes, frogs, little birds, and so on. Their strong bill and long neck is perfectly designed for it to have the maximum reach and a powerful grip. It even uses this bill to stab and impale prey.

They are known for their ability to stand absolutely still for extended periods of time, even hours, as they wait for prey. They may also dive down from the air into the water to catch fish. If the fish is too large to swallow in one whole gulp, the bird will discard it.

Socialisation

The grey heron is a sociable bird and will nest with a sizeable group of other individuals. They are most active in the early morning and just before sunset. While they usually hunt alone, they will consider feeding in a group if there is plenty of food available.

Communication

This bird has a loud, jarring voice. Their call, which sounds like a croaky “fraaank”, is normally used during flight or while they are nesting.

Reproduction

The grey heron is a monogamous bird that will likely stick to an established heron nesting area, set up by previous generations in their natural habitat. These are called heronries.

This bird will breed in a colony or as an individual, using flat nests in the tops of the trees that are close to wetlands, lakes or other water sources. These nests have been constructed using sticks and twigs, and are then lined with grass and fresh leafy branches. The male presents the female with these building materials in a rather ritualistic way before she proceeds to construct the actual nest.

The female usually lays between three and six eggs during autumn or in the early part of winter. The male and female take turns to incubate these eggs for almost four weeks before they hatch.

The tiny chicks are fed fish by means of regurgitation. They will take between 20 and 30 days to fledge. However, chicks have been known to kill one another in the nest as a result of extreme rivalry, even before fledging. The parents may also neglect the youngest, as they almost always favour the oldest chick.

Incubation

Incubation lasts 25 to 26 days.

Life Expectancy

The Blue Heron lives for about 15 years.

Threats

While they have very good population numbers and are not considered to be of concern to conservation organisations, the grey herons do face some challenges. These include the loss of viable breeding grounds and natural habitat, as well as being killed by fish farmers that do not want them hunting their produce.

References

Naturia; ARKive; RSPB; Biodiversity Explorer.