Large nocturnal travellers

If your local park has a big lake, or if you go for a walk along the foreshore of the Swan or Canning Rivers, you are no doubt familiar with Western Australia’s bird emblem, the iconic Black Swan (Cygnus atratus), known as ‘marli’ or ‘koltjak’ in the Noongar language.1 “Atratus” means “dressed in black.” 2

The black swan is a graceful large waterbird with black plumage, white wing tips which are visible when in flight and an orange-red bill. They are the only entirely black coloured swan in the world.3 Immature birds are much greyer with black wing tips.3 Their body is 100–140 cm long, with a wing span of almost 2 metres. Males have a larger neck and, when swimming, they hold their neck more erect. 2

Black swans live in large salt, brackish or fresh water waterways and permanent wetlands. They travel between wetlands at night under cover of darkness where they blend in with shadows.4

Black swans mate for life and can live up to 40 years.2 They breed between June and September with females laying a clutch of up to 10 and pairs sharing incubation duties and cygnet rearing. Nests are untidy, made up of reeds and grasses placed on a small island or floated in deeper water. One brood is raised per season and chicks are able to swim and feed themselves as soon as they hatch.3

Black swans are vegetarian and mainly eat algae and weeds. They obtain these by plunging their beaks into water up to 1 metre deep and less frequently, because they are clumsy out of the water, by grazing on land.3

 

Sources:

1iNSiGHT Ornithology

2 WA Bird Emblem

3 Australian Museum

4https://perthzoo.wa.gov.au/animal/black-swan