Corcoracidae is a family of

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by t ...

birds known as the Australian mudnesters. The family has sometimes been called Struthideidae in the past; however, despite Struthideidae being an older name than Corcoracidae, the latter name takes precedence. It contains just two

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

in two genera, the

white-winged chough 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 ...

(''Corcorax melanorhamphos'') and the

apostlebird The apostlebird (''Struthidea cinerea''), also known as the grey jumper, lousy jack, happy jack, Donny bird or caw bird is a quick-moving, gray or black bird about 33 cm (13 in) long. It is a native to Australia where it roams woodlands ...

(''Struthidea cinerea''). Both are endemic to

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

Distribution and habitat

Both the Australian mudnesters are found in open

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

in eastern Australia, mostly open

eucalypt Eucalypt is a descriptive name for woody plants with capsule fruiting bodies belonging to seven closely related genera (of the tribe Eucalypteae) found across Australasia: ''Eucalyptus'', '' Corymbia'', '' Angophora'', ''Stockwellia'', ''Allosyn ...

woodlands and some forest that lacks a closed canopy. The apostlebird is more tolerant of arid habitats and is found in arid

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...

and

shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It m ...

s. Both species are tolerant of human modified

s and will occupy

farmland Agricultural land is typically land ''devoted to'' agriculture, the systematic and controlled use of other forms of lifeparticularly the rearing of livestock and production of cropsto produce food for humans. It is generally synonymous with bot ...

s and suburban areas, and even parks and gardens.

Description

The two mudnesters are medium-sized passerines, the apostlebird being smaller at around in length and the larger white-winged chough averaging . Their morphology is typical of ground feeding passerines, with long legs and short, rounded wings. The most noticeable differences between the two species are in the

plumage Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...

(grey with brown wings and a black tail in the apostlebird, and black with white wing patches in the white-winged chough) and

bill Bill(s) may refer to: Common meanings * Banknote, paper cash (especially in the United States) * Bill (law), a proposed law put before a legislature * Invoice, commercial document issued by a seller to a buyer * Bill, a bird or animal's beak Plac ...

shape. The bill of the apostlebird is short and deep, not unlike that of a

finch The true finches are small to medium-sized passerine birds in the family Fringillidae. Finches have stout conical bills adapted for eating seeds and nuts and often have colourful plumage. They occupy a great range of habitats where they are usua ...

, whereas the bill of the white-winged chough is long and curved, not unlike that of its Old World namesakes, the

chough There are two species of passerine birds commonly called chough ( ) that constitute the genus ''Pyrrhocorax'' of the Corvidae (crow) family of birds. These are the red-billed chough (''Pyrrhocorax pyrrhocorax''), and the Alpine chough (or yellow- ...

s. The differences in the bills reflect the differences in feeding ecology, with the apostlebirds using theirs for sparrow-like picking whereas the white-winged chough uses its bill to flick leaf litter around.

Behaviour

In the field, the relationship between the two species is immediately apparent: both species are highly social, spending much of their time foraging through leaf litter with a very distinctive gait, calling to one another almost constantly. 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 Preening is a found in birds that involves the use of the beak to position feathers, interlock feather that have become separated, clean plumage, and keep ectoparasites in check. Feathers contribute significantly to a bird's insulation, waterp ...

. 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. Both species are non migratory and defend a territory during the breeding season. The size of the territory during the breeding season is around 20 ha, after the breeding season when the chicks are

fledge Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable c ...

d the group may range over a larger territory. On the death of one of the dominant breeders the groups break up, and the remaining dominant bird will take immatures from their group and find a lone bird to form a new group. The majority of recruits into any group after its establishment are youngsters from previous breeding seasons. These helpers are important in breeding success, so much so that white-winged choughs have been reported to kidnap nearly fledged chicks from other groups in order to increase the size of the kidnapping group. As the common name of the family suggests, the

nests A nest is a structure built for certain animals to hold eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of organic materi ...

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 Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

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.

Species

White-winged chough 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 ...

, ''Corcorax melanorhamphos'' *

Apostlebird The apostlebird (''Struthidea cinerea''), also known as the grey jumper, lousy jack, happy jack, Donny bird or caw bird is a quick-moving, gray or black bird about 33 cm (13 in) long. It is a native to Australia where it roams woodlands ...

, ''Struthidea cinerea''

References

External links

White-winged Chough & Apostlebird videos, photos & sounds
on the Internet Bird Collection {{Taxonbar, from=Q579399 . Higher-level bird taxa restricted to Australia Taxa named by Gregory Mathews