Species Fact Profile: Black Swan (Cygnus atratus)

Black Swan

Cygnus atratus (Latham, 1790)

Range:  Australia (Includes Tasmania)

Habitat:  Lakes, Rivers, Wetlands

Diet:  Aquatic Plants, Grasses, Insects

Social Grouping: Pairs, Family Groups, Loose Colonies

Reproduction: Monogamous (often for life), breed February through September; a nest of sticks and leaves is built on a floating mound in water; the 5-6 eggs are incubated for 35-48 days by both parents, chicks fledge 150-170 days, are independent at 9 months, and sexually mature at 18-36 months; juveniles form their own flocks

Lifespan:  40 Years

Conservation Status: IUCN Least Concern

• Body length 110-140 centimeters, wingspan 160-200 centimeters, weight 3.7-8.7 kilograms (males are slightly larger than females)
• Black plumage with some white wing feathers, a red bill, and red or pink irises; juveniles are gray-brown with lighter bills than the adults
• Black swans have the longest neck in relation to their body size of any swan species; the neck is often curved into “S” shape
• Birds molt after the breeding season and unable to fly for a month or so
• The least territorial of all swans, they sometimes form colonies
• Largely sedentary, they will become nomadic in times of food scarcity
• Adults have few predators, but eggs and fledglings can be taken by ravens, raptors, gulls, predatory marsupials, and rodents
• They have been introduced to Europe and North America; vagrants have been reported in Indonesia and New Guinea
• A subspecies (C. a. sumnerensisi) was hunted to extinction present in New Zealand; birds of Australian stock were then introduced to New Zealand and have become established
• Considered a crop pest in some areas, they hunted legally during a short annual season
• State bird of Western Australia, appearing on Coat of Arms and flag; important in aboriginal lore (in most versions, swans were originally people; in some versions they were originally white and were given black feathers by crows)
• Prior to 1697 discovery, “black swan” was European metaphor for something that couldn’t exist