Black Swan necks have evolved great length (1) which helps them reach benthic vegetation in both fresh and saline shallow waters. With their necks fully stretched and by upending, dabbling, swans extend the area of potential food habitat available to them, and they also graze on land. The Gippsland Lakes have large areas of relatively shallow waters with rich beds of aquatic vegetation making ideal habitat for Black Swans which are generally abundant and can be found at times in large numbers in some locations on the Lakes (2), especially where there are large sea-grass meadows.
Swan breeding on the Gippsland Lakes tends to be episodic, that is in irregular bursts triggered by food abundance in response to unpredictable but favourable environmental conditions, especially after good rains. The last big swan breeding event on the Lakes took place back in 2019 when large numbers of swans could be found in many locations on nests and on the water with cygnets (3).
Swans can breed alone or in colonies. In colonies aggressive behaviour between nesting birds is often on display. Distance between nests can be established by the length of a very long outstretched neck. Some individual birds seem to be particularly intolerant of other birds near their nests. Signs of swan aggression include arched neck with feathers raised, hissing, pecking and so on which is termed Agonistic behaviour (4).
The following photos capture some of this behaviour with one swan demonstrating just how long their necks are.
NOTE: You can left click on any photo to open a slide show of the photos free of text or a right click enables one photo at a time to be opened in a New Tab where an enlarged version can be viewed.
In the following photo the swan shows the arched neck with feathers held out – bristling - and the wings are also held slightly out.
The next photo shows the cause of the threat display – another swan too close to its nest.
The following photo shows a swan on a nest with an outstretched neck, which is a show of aggression towards another swan on an adjoining nest. There was plenty of space available however these two swans have ended up with nests just within pecking reach.
Recently hatched cygnets on a nest.
This young chick is struggling to climb back into a nest.
The Swan’s musical bugle is distinctive and evocative of wetland habitats.
Black Swans are an iconic bird species in Australia and especially in Western Australia where they were first found, by non-indigenous people, when the Dutch explorer Willem Hesselsz de Vlamingh discovered them in 1697 on the subsequently named Swan River in WA. They are the WA State bird featuring on their coat of arms and the name Black Swan has been adopted for many purposes from the name of beer to a football team. More recently a Black Swan event, aka a Black Swan, has been adopted to describe a highly unlikely and unpredictable occurrence that has major worldwide repercussions, usually dire ones, but which, in hindsight, the factors leading up to the event were obvious (for those interested the origin of this recently coined term this can easily be found with a Google search).
Notes:
(1) Fun fact: Black swans have 25 neck (cervical) vertebrae. This high number of vertebrae provides their long necks with exceptional flexibility, far exceeding the seven cervical vertebrae typically found in most mammals. Taxonomists classify waterfowl based on the number of cervical vertebrae they have. Ducks have 16 or fewer neck vertebrae, geese have 17-23 neck vertebrae, and swans have 24 or 25 neck vertebrae. I assume the large number of swan neck vertebrae originated in their dinosaur ancestors? You would think Giraffes have a large number of neck vertebrae but they only have seven, the same number as humans and almost all other mammals.
(2) For example on 26/01/2026 BirdLife East Gippsland members counted from the lookout at Nyerimilang Park 1,200 Black Swans on the Lake in the vicinity of Fraser and Flannagan Islands.
(3) Swan breeding: Usually 5-6 eggs and up to 10 with incubation taking 35-45 days. The following text taken from the Reader’s Digest, The Complete Book of Australian Birds, provides an interesting summary of Black Swan reproduction which can seem rather chaotic at times:
“Black Swans are ready to breed at the age of 18 months, and most breed before the end of 3 years. Young birds about to breed for the first time may form a pair only temporarily – if a clutch is produced, either partner may leave the other to incubate the eggs and raise the young alone. The deserting partner usually mates again to rear another brood. In this way there may be as many as four broods in the one year from clutches laid by one female. Among older birds pair formation is generally permanent, but if a mate is lost the remaining bird will quickly mate again. The nest is a mound of whatever material – sticks, leaves, rushes or other aquatic plants – can be accumulated around the incubating bird. Its construction may begin just before or, or if the nest is on an island, soon after the first egg is laid and may continue for at least three or four weeks during egg-laying and incubation. Depending on the supply of material, the size of the nest will vary from a simple ring of plant matter to a large mound. On islands where swans breed in colonies, nests are often destroyed as the swans pilfer one another’s nest material. As eggs are deserted and scattered, neighbouring swans scrape them into their nests and incubate them.”
(4) Agonistic behaviour in birds involves aggressive interactions over resources like food, mates, or territory, using signals like vocalisations, displays such as threat postures and physical attacks including chasing, pecking and biting.
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