Darter, male, drying its wings.
Photo: K Vang and W Dabrowka © Bird Explorers
Darter.
Photo: Purnell Collection © Australian Museum
Darter.
Photo: Purnell Collection © Australian Museum
Distribution map of Anhinga melanogaster
Map © Birds Australia Birdata
Darter
Scientific name: Anhinga melanogaster
Family: Anhingidae
Order: Pelecaniformes
- Featured Bird Groups
- Water birds
What does it look like?
Description
The Darter is a large, slim water bird with a long snake-like neck, sharp pointed bill, and long, rounded tail. Male birds are dark brownish black with glossy black upperwings, streaked and spotted white, silver-grey and brown. The strongly kinked neck has a white or pale brown stripe from the bill to where the neck kinks and the breast is chestnut brown. Females and immatures are grey-brown above, pale grey to white below, with a white neck stripe that is less distinct in young birds. The Darter is often seen swimming with only the snake-like neck visible above the water, or drying its wings while perched on a tree or stump over water. While its gait is clumsy on land, it can soar gracefully to great heights on thermals, gliding from updraft to updraft. It has a cross-shaped silhouette when flying. The Australian species should now be known as the Australasian Darter, Anhinga novaehollandiae (see Distribution).
Similar species
The Darter's slender body, long, snake-like neck and its pointed, rather than hooked, bill distinguishes it readily from the bulkier cormorants with which it is often found.
Where does it live?
Distribution
In Australia, the Darter is found from Adelaide, South Australia, to Tennant Creek, Northern Territory and then to Broome, Western Australia. it is also found in south-western Australia, from Perth to Esperance. Worldwide, it has been thought of as one of two main Anhinga species (the other, A. anhinga, is found in North America), found in the southern half of Africa, Madagascar, Iraq, Pakistan, India, south-east Asia, Indonesia and New Guinea. However, A. melanogaster is now considered to be further divided into three species, with rufa being found in Africa, melanogaster in south Asia and novaehollandiae in New Guinea and Australia (the Australasian Darter).
Habitat
The Darter is found in wetlands and sheltered coastal waters, mainly in the Tropics and Subtropics. It prefers smooth, open waters, for feeding, with tree trunks, branches, stumps or posts fringing the water, for resting and drying its wings. Most often seen inland, around permanent and temporary water bodies at least half a metre deep, but may be seen in calm seas near shore, fishing. The Darter is not affected by salinity or murky waters, but does require waters with sparse vegetation that allow it to swim and dive easily. It builds its nests in trees standing in water, and will move to deeper waters if the waters begin to dry up.
Seasonal movements
Darters can move over long distances (over 2000 km) when not breeding, but populations tend to contract to breeding areas during summer.
What does it do?
Feeding
The Darter catches fish with its sharp bill partly open while diving in water deeper than 60 cm. The fish is pierced from underneath, flicked onto the water's surface and then swallowed head first. Smaller items are eaten underwater and large items may be carried to a convenient perch and then swallowed. Insects and other aquatic animals, including tortoises, may also be eaten, as well as some vegetable matter. In hot weather, adult birds may pour water from their bills into the gullets of their young chicks when they are still in the nest.
Breeding
The Darter is usually a solitary bird, forming pairs only while breeding. Breeding is erratic, happening whenever water levels and food supplies are suitable, but most often occurs in spring and summer. Nests are usually solitary, but Darters may nest within loose colonies with other water birds that nest in trees, such as cormorants, spoonbills and ibis. The male decorates a nest-site with green leafy twigs and displays to attract a mate, with elaborate wing-waving and twig-grasping movements. The male carries most of the nest material to the nest-site, which is normally in the fork of a tree standing in water, usually about 3.5 m above the water's surface. Both sexes complete the nest, incubate the eggs and raise the young. Chicks are kept warm by brooding continously (or cooled down by shading with spread wings) for up to a week after hatching and both adults stay in the nest with the chicks overnight. In hot weather, the adults will even shake water over the chicks after a swim. Chicks can swim after about four weeks in the nest and start to fly at about 50 days.
Living with us
Living with humans
Although the deep, open water bodies that Darters favour suffer less from drainage than other wetland types, Darters are still threatened by increased salinity, clearing, grazing, increased fire frequency and extraction of groundwater. Because Darters often feed on introduced fish species such as Carp and Redfin Perch, they may be adversely affected by attempts to reduce numbers of these fish species. Darters are also often casualties of duck-shooting, with birds being shot or disturbed from their nests and losing their eggs to ravens. Adults may also drown if trapped in fishing nets.
References
Marchant, S. and Higgins, P.J. (eds). 1993. Handbook of Australian, New Zealand and Antarctic Birds. Vol 1B (Ratites to Ducks), Oxford University Press, Sydney.
Morcombe, M. 2000. Field guide to Australian Birds. Steve Parish Publishing.
Simpson, K and Day, N. 1999. Field guide to the birds of Australia, 6th Edition. Penguin Books, Australia.