Corcoracidae – Australian Mudnesters

Apostlebird Struthidea cinerea ©Ian Montgomery Website

The Corcoracidae are taxonomic family within the order Passeriformes commonly known as Australian mudnesters.

Both the Australian mudnesters are found in open habitat in eastern Australia, mostly open eucalypt woodlands and some forest that lacks a closed canopy. The apostlebird is more tolerant of arid habitats and is found in arid woodland and shrublands. Both species are tolerant of human modified habitats and will occupy farmlands and suburban areas, and even parks and gardens.

As the common name of the family suggests, the nests are constructed out of mud. These bowl shaped nests take several days to construct, longer if supplies of mud dry up before the nest is finished. nests are built opportunistically when rain causes muddy puddles, and may be reused if possible. Around three to five oval eggs are laid in each clutch. These eggs are incubated for around twenty days by all members of the group, and feeding and brooding duties are also shared within the group. This family has a very long period of fledgling care, with full independence from the parents and helpers taking up to 200 days.

The two species are medium-sized passerines, the apostlebird being smaller at around 31 centimetres in length and the larger white-winged chough averaging 47 centimetres. Their morphology is typical of ground feeding passerines; long feathered legs and short, rounded wings. The most noticeable differences between the two species are in the plumage, which is generally dull, and in the bill. The bill of the apostlebird is short and deep, not unlike that of a finch, whereas the bill of the white-winged chough is long and curved, not unlike that of its Old World namesakes, the choughs. The differences in the bills reflect the differences in feeding, with the apostlebirds using theirs for sparrow-like picking whereas the white-winged chough uses its bill to flick leaf litter around.

In the field, the relationship between the two species is immediately apparent: both species are highly social, spend much of their time foraging through leaf litter with a very distinctive gait, calling to one another almost constantly, and both species respond to a human interloper by flying heavily to a nearby tree, where they wait for the disturbance to pass, often perching close together in twos and threes and allopreening. In picnic grounds and parks these birds may become accustomed to humans and become very tame. The social groups of mudnesters are based around a dominant male and female. The number of birds in the group may vary from two to twenty birds, six birds being typical in the white-winged chough and seven to nine birds in the apostlebird, although the latter was named as it was often seen in groups of around a dozen birds.

There are just two species in this family of Australian Mudnesters, which are:

White-winged Chough Corcorax melanorhamphos

Apostlebird Struthidea cinerea

Species Links
  • Apostlebird Struthidea cinerea

    BirdLife Species Account
    ...The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern...
  • Apostlebird Struthidea cinerea

    Species Account
    The Apostlebird is a medium-sized dark grey bird with a short strong bill, brown wings and black tail. It is normally seen in groups of six to ten birds, and is usually seen on the ground. It belongs to the group of birds known as 'mud-nesters', the Family Corcoracidae, noted for their communal life style and their bowl nests constructed of mud and plant fibres....
  • Apostlebird Struthidea cinerea

    HBW Species Account
    axonomy: Struthidea cinerea Gould, 1837, interior of New South Wales, Australia. Family treatment much disputed over the years, and present species has frequently been placed in Grallinidae or a monospecific Struthideidae; close relationship with Corcorax generally agreed. Races intergrade in NC Queensland. Isolated population in Northern Territory formerly thought to represent a distinct race from that in N Queensland, but now considered identical. Although name swainsoni predates dalyi, former regarded as invalid, as description and measurements of type specimen ambiguous and possibly based on intermediate specimen, and type locality (N Queensland) imprecise and could lie within zone of intergradation with nominate. Two subspecies recognized....
  • Apostlebird Struthidea cinerea

    Species Account
    The sexes are similar. The adult has a dark gray plumage with pale gray streaks particularly visible on the head, coat, throat and chest. Its wings are brown and long tail feathers of the tail are black with green highlights. The beak robust is black. The legs and feet are blackish. The color of the iris varies with age: in nestlings, they are brown, in immature than a year, they are gray, adults aged at least two years, they are gray with narrow yellow eye ring . This ring becomes wider and more prominent as and as the bird gets older...
  • Apostlebird Struthidea cinerea

    Species Account
    Sound archive and distribution maps
  • Apostlebird Struthidea cinerea

    Species Account
    The apostlebird (Struthidea cinerea), also known as the grey jumper, lazy jack or cwa bird is a quick-moving, gray or black bird about 13 inches (33 centimetres) long. It is a native to Australia where it roams woodlands, eating insects and seeds at, or near, ground level. Apostlebirds often travel in groups of about 12; for this reason they were named after the Biblical apostles, the twelve chief followers of Jesus Christ...
  • Apostlebird Struthidea cinerea

    JCU Species Account
    This noisy gregarious bird is commonly found in open woodland areas, although it has been recorded on campus it is very common in drier areas. These ground feeding birds are found in groups of 6 or more, there may even be up to about 100 in a group. Body is grey with some darker flecks, head is grey, wings brownish, the long tail is black. Legs and feet dark grey to black, eyes brown, bill black...
  • White-winged Chough Corcorax melanorhamphos

    BirdLife Species Account
    ...The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern....
  • White-winged Chough Corcorax melanorhamphos

    Species Account
    The White-winged Chough is a large, almost completely black bird. It has a curved beak, a red eye and a large white wing patch, which is seen when the bird is in flight. The bill and legs are black. Both male and female share the same plumage pattern. Young White-winged Choughs start off duskier than the adults, and the eye is brown. They do not reach sexual maturity until four years of age and, during this time, the eye changes from brown to orange and then to red, and the plumage darken
  • White-winged Chough Corcorax melanorhamphos

    HBW Species Account
    Taxonomy: Coracia melanoramphos Vieillot, 1817, New South Wales, Australia. Family treatment much disputed over the years, and present species has variously been placed in Corvidae, Grallinidae or a monospecific Corcoracidae; close relationship with Struthidea generally agreed. Geographical variation minimal, and species formerly treated as monotypic. Races intergrade in SE South Australia (in and just E of Mt Lofty Ranges). Proposed race subniger (from Ringwood, in Victoria) synonymized with nominate. Species name often misspelt "melanorhamphos". Two subspecies currently recognized.
  • White-winged Chough Corcorax melanorhamphos

    Species Account
    Sound archive and distribution maps
  • White-winged Chough Corcorax melanorhamphos

    Species Account
    The white-winged chough (Corcorax melanorhamphos) is one of only two surviving members of the Australian mud-nest builders family, Corcoracidae, and is the only member of the genus Corcorax. It is native to Southern and Eastern Australia and is an example of convergent evolution as it is only distantly related to the European choughs that it closely resembles in shape, and for which it was named.
Number of Species
  • Number of bird species: 2

Other Links
  • Apostlebirds Corcoracidae

    Website
    The Apostlebirds are a small Australian family composed of just two species: the Apostlebird (left) and the White-winged Chough Corcorax melanorhamphos

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