Australian darter (Anhinga novaehollandiae)

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Australian darter fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Australian darter description

Like other darter species, the Australian darter (Anhinga novaehollandiae) looks very much like a cormorant in terms of its overall shape ⁽³⁾, although its neck is longer and more slender ^{(3) (4)}. Darters tend to carry their necks in a characteristic kinked, ‘Z’ shape posture ^{(3) (4)}, and have long tails and short legs ending in elongated webbed toes. Interestingly, each mandible of the darter’s long, stiletto-like bill has a cutting edge ⁽³⁾.

The adult male Australian darter has glossy, dark brown upperparts, which are accentuated by silvery plumes and by silvery fringes on the wing feathers, and a fine white stripe on the face. Greyer upperparts and white underparts with a buffy hue to the neck distinguish the female Australian darter from the male. The female also has narrow white and black stripes on the face, while juvenile Australian darters are much like the female but paler ⁽⁴⁾. In the juvenile birds, the black and white parts are usually replaced by brown and buff ⁽²⁾, and these young individuals are often less obviously marked than the adults ⁽⁴⁾.

Frequently spotted perching on branches overhanging the water, the Australian darter often rests with its wings held open, whereas when it is soaring high in flight it tends to fan out its tail. This species flies with shallow, rapid wing beats. Like other darter species, the Australian darter swims so low in the water that sometimes only its head and upper neck are exposed ⁽⁴⁾.

The Australian darter is sometimes considered to be a subspecies of the Oriental darter (Anhinga melanogaster) ^{(2) (5)}.

Also known as

Australasian darter.

Synonyms

Anhinga melanogaster novaehollandiae.

Size

Length: 85 - 97 cm ⁽²⁾

Wingspan: 116 - 128 cm ⁽²⁾

Weight

1,058 - 1,815 g ⁽²⁾

Australian darter biology

Usually seen singly or in loose groups on lakes ⁽⁴⁾, the Australian darter is a strong flier ⁽³⁾, but is mainly a sedentary species ⁽²⁾, only migrating sporadically in response to drought conditions and regional food shortages ^{(2) (3)}.

Although the Australian darter’s prey preferences change depending on the location, this species’ diet is known to comprise mostly fish, which are not chased but are instead speared directly underwater. Amphibians, water snakes, terrapins and aquatic invertebrates such as insects and crustaceans are also known to be taken ⁽²⁾.

Breeding in darter species is known to be seasonal in some parts of their range, and occurs at any time of year in others. The Australian darter tends to be a colonial breeder, often being seen in the company of cormorants and other wading birds. Its nest is often placed about two metres above the water and consists of a platform of sticks and reeds, into which the female lays between two and six eggs, although three to five is most common. The eggs are incubated for between 26 and 30 days, after which time the naked chicks hatch. The chicks grow whitish down, and are capable of flight approximately seven weeks after hatching. It is thought that the Australian darter does not reach sexual maturity until it is at least two years old, and individuals of this species have been known to live for more than nine years in the wild, and even longer in captivity ⁽²⁾.

Australian darter range

The Australian darter is found mainly in Australia and New Guinea ^{(2) (3) (4) (5) (6)}, but it has also been reported to occur in Timor-Leste ⁽⁵⁾, the Lesser Sunda Islands and the southern Moluccas ⁽⁶⁾. This species has been recorded as a vagrant in New Zealand ⁽⁵⁾.

Australian darter habitat

The Australian darter frequents still, shallow inland waters ⁽²⁾, including lakes, swamps, lagoons, reservoirs and slow-flowing rivers ^{(2) (6)}, and requires its habitat to include scattered emergent trees, forested margins or, on islets, dense vegetation cover ⁽²⁾. This species also occurs in estuaries ^{(2) (6)}, tidal inlets and coastal zones associated with mangroves ⁽²⁾.

Australian darter status

The Australian darter is classified as Least Concern (LC) on the IUCN Red List ⁽¹⁾.

Australian darter threats

The Australian darter has a moderately large population covering an extremely large range ⁽⁵⁾, and it is not currently considered to be globally threatened ⁽²⁾. However, despite being widespread and common throughout much of Australia ⁽²⁾, it is thought that the Australian darter’s population fluctuates along with changes in its wetland habitat ⁽⁵⁾, and habitat destruction and pollution have been identified as possible key threats to this species ⁽²⁾.

Australian darter conservation

There are currently no known conservation measures in place specifically for the Australian darter.

Find out more

Find out more about the Australian darter:

• BirdLife International - Australian darter:
  http://www.birdlife.org/datazone/speciesfactsheet.php?id=3663

Learn more about bird conservation in Australia:

• BirdLife Australia:
  http://www.birdlife.org.au/

Find out more about conservation in Australia:

• Australian Wildlife Conservancy:
  http://www.australianwildlife.org/
• Australian Conservation Foundation:
  http://www.acfonline.org.au/

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Glossary

Crustaceans

Diverse group of animals with jointed limbs and a hard external skeleton, characterised by the possession of two pairs of antennae, one pair of mandibles (mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, woodlice and barnacles.

Incubation

The act of incubating eggs; that is, keeping them warm so that development is possible.

Invertebrates

Animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.

Mandible

In birds, the lower jaw and beak, but the term is also used to denote the two parts of the beak.

Plume

An ornamental feather that is usually long and conspicuous, and is used by a bird for display.

Subspecies

A population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.

Vagrant

An individual found outside the normal range of the species.

References

1. IUCN Red List (April, 2013)
   http://www.iucnredlist.org/
2. del Hoyo, J., Elliott, A. and Sargatal, J. (1992) Handbook of the Birds of the World. Volume 1: Ostrich to Ducks. Lynx Edicions, Barcelona.
3. Burton, M. and Burton, R. (2002) International Wildlife Encyclopedia. Marshall Cavendish, Singapore.
4. Dutson, G. (2012) Birds of Melanesia: Bismarcks, Solomons, Vanuatu, and New Caledonia. A&C Black Publishers, London.
5. BirdLife International - Australian darter (April, 2013)
   http://www.birdlife.org/datazone/speciesfactsheet.php?id=3663
6. Sibley, C.G. and Monroe Jr, B. (1991) Distribution and Taxonomy of Birds of the World. Yale University Press, Connecticut.