Egrets at HWCA
Egrets, Herons and Bitterns all belong to the family Ardeidae. They are medium-sized to large or very large wading birds characterised by their long necks and long legs. In Australia there are 14 resident species of Egret, Heron and Bitterns.
During 1981, Dr. Max Maddock (then Associate Professor of Education at University of Newcastle), was studying the breeding behaviour and breeding success of a breeding colony of egrets in the Melaleuca Swamp Forest in the Shortland Wetlands. It was during this work that Max began evolving a concept for using the building and wetlands as a biological education and research centre with the egrets as one of its main features.
To read about the campaign and efforts by The Hunter Wetlands Group to protect this breeding colony click here.
Since 1981, the Hunter Wetlands Centre has been an important site for a breeding colony of four Egret species such as the:
- Little Egret
- Intermediate Egret
- Great Egret
- Cattle Egret
These birds build stick nests in trees usually over water. They nest at extremely high densities, with often more than 20 nests in each tree. One to three Great Egret pairs usually occupy the upper-most branches, and the other three species occupy the lower branches.
The Hunter Wetlands Centre along with the Seaham Swamp Nature Reserve are the most important breeding sites in the lower Hunter Valley. In 1988/89 there were 198 Great Egret nests; 453 Intermediate Egret nests; 57 Little Egret nests; and a massive 1,393 Cattle Egret nests at the site. Cattle Egrets began breeding at Seaham in 1978/79 and have nested each year since. The nesting birds are a feature of these two sites every year.
Since 1985, the egrets have been the focus of Project Egret Watch, which studied the breeding biology, ecology and migration of the birds. The project is registered with the Australian Bird and Bat Banding Scheme as an official bird-banding project. The banding and tagging undertaken as part of the project enabled the recognition of individual birds and the tracking of the behaviour and movement over their life span as part of a research project of the Hunter Wetlands Centre.
The project tagged Great, Intermediate and Little egrets at the Wetlands Centre, several colonies in northern New South Wales and Queensland, in the Macquarie Marshes and at Dowd’s Morass in Gippsland (Vic). More than 200 volunteer observers in Australia and New Zealand kept a look out for tagged birds at the peak of the project’s operations in the late 1980s and early 90s, resulting in more than 20,000 live sightings of tagged birds being reported during this time. The results of the research, in which work at Seaham figured prominently, have been published in the scientific literature (eg Maddock 1990c, Maddock and Bridgman 1992, Maddock and Geering 1994) and in each issue of the Hunter Wetlands Trust Newsletter and then in its successor The Wetlander. The research has solved many of the mysteries of the egret life style, breeding behaviour and migration because of the tags making it possible to identify individual birds wherever they travelled during their lifetime.
You can read the latest Project Egret Watch news here: The Wetlands Centre - Project Egret Watch.pdf[203Kb PDF doc]
Some results of the project reveal that:
Most birds return to the colony of their birth but choose a different mate and usually a different nest location each year.
Few birds survive for more than one year.
The longest survivor on record was 11years old.
The Lower Hunter region is a staging place for the southern migration of Cattle Egrets from Queensland and northern New south Wales colonies.
Most of the nests are built in the Broad-leaved Paperbark trees, with some in the Casuarinas.
The male bird fetches the sticks for nest building but both share about equally the construction of the nest, incubation of the eggs and the feeding of the young.