Corcoracidae
Encyclopedia
The Australian mudnesters are passerine
family Struthideidae. The family is often commonly called Corcoracidae, however this is the junior synonym. It contains just two species
in two genera, the White-winged Chough
, Corcorax melanorhamphos, and the Apostlebird
Struthidea cinerea. Both are endemic to Australia
.
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 shrubland
s. Both species are tolerant of human modified habitat
s and will occupy farmland
s and suburban areas, and even parks and gardens.
, 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 chough
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.
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
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
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.
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
family Struthideidae. The family is often commonly called Corcoracidae, however this is the junior synonym. It contains just two species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
in two genera, the White-winged Chough
White-winged Chough
The White-winged Chough is one of only two surviving members of the Australian mud-nest builders family, Corcoracidae, and is the only member of the genus Corcorax...
, Corcorax melanorhamphos, and the Apostlebird
Apostlebird
The Apostlebird , also known as the Grey Jumper, is a quick-moving, gray or black bird about 13 inches long. It is a native to Australia where it roams woodlands, eating insects and seeds at, or near, ground level...
Struthidea cinerea. Both are endemic to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
.
Distribution and habitat
Both the Australian mudnesters are found in open habitatHabitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
in eastern Australia, mostly open eucalypt
Eucalypt
Eucalypts are woody plants belonging to three closely related genera:Eucalyptus, Corymbia and Angophora.In 1995 new evidence, largely genetic, indicated that some prominent Eucalyptus species were actually more closely related to Angophora than to the other eucalypts; they were split off into the...
woodlands and some forest that lacks a closed canopy. The Apostlebird is more tolerant of arid habitats and is found in arid woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
and shrubland
Shrubland
Shrubland, scrubland, scrub or brush 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...
s. Both species are tolerant of human modified habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s and will occupy farmland
Farmland
Farmland generally refers to agricultural land, or land currently used for the purposes of farming. It may also refer to:*Arable land, land capable of cultivating crops*Farmland, Indiana, a town in the United States...
s and suburban areas, and even parks and gardens.
Description
The two mudnesters are medium sized passerines, the Apsotlebird being smaller at around 31 centimetres (12.2 in) in length and the larger White-winged Chough averaging 47 centimetres (18.5 in). 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 plumagePlumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
, which is generally dull, and in the bill
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
. The bill of the Apostlebird is short and deep, not unlike that of a finch
Finch
The true finches are passerine birds in the family Fringillidae. They are predominantly seed-eating songbirds. Most are native to the Northern Hemisphere, but one subfamily is endemic to the Neotropics, one to the Hawaiian Islands, and one subfamily – monotypic at genus level – is found...
, whereas the bill of the White-winged Chough is long and curved, not unlike that of its Old World namesakes, the chough
Chough
The Red-billed Chough or Chough , Pyrrhocorax pyrrhocorax, is a bird in the crow family; it is one of only two species in the genus Pyrrhocorax...
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 Choughs and Apostlebirds 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. Both species are non migratory
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
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
Fledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
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
Bird nest
A bird nest is the spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest of the American Robin or Eurasian Blackbird, or the elaborately woven hanging nest of the...
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
Bird egg
Bird eggs are laid by females and incubated for a time that varies according to the species; a single young hatches from each egg. Average clutch sizes range from one to about 17...
are laid in each clutch. These eggs are incubated
Avian incubation
Incubation refers to the process by which certain oviparous animals hatch their eggs, and to the development of the embryo within the egg. The most vital factor of incubation is the constant temperature required for its development over a specific period. Especially in domestic fowl, the act of...
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 ChoughWhite-winged ChoughThe White-winged Chough is one of only two surviving members of the Australian mud-nest builders family, Corcoracidae, and is the only member of the genus Corcorax...
, Corcorax melanorhamphos - ApostlebirdApostlebirdThe Apostlebird , also known as the Grey Jumper, is a quick-moving, gray or black bird about 13 inches long. It is a native to Australia where it roams woodlands, eating insects and seeds at, or near, ground level...
, Struthidea cinerea
External links
- White-winged Chough & Apostlebird videos, photos & sounds on the Internet Bird Collection