Mud nesting crows

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Mud nesting crows
Bluebird (Corcorax melanorhamphos)

Bluebird ( Corcorax melanorhamphos )

Systematics
Subclass : New-jawed birds (Neognathae)
Order : Passerines (Passeriformes)
without rank: Eupasseres
Subordination : Songbirds (passeri)
Superfamily : Corvoidea
Family : Mud nesting crows
Scientific name
Corcoracidae
Mathews , 1927

The mud-nest crows (Corcoracidae, Syn .: Struthideidae), also blue jays, are a family of songbirds (Passeri) within the order of passerine birds (Passeriformes) that occur in Australia . It comprises two genera, each with one type, the Gimpelhäher ( Struth Idea cinerea ) and the throttle Crow ( Corcorax melanorhamphos ).

features

The bull jay ( Struthidea cinerea ) is smaller than the thrush crow

The thrush crow grows to 47 cm, while the bull jay is considerably smaller at 33 cm. The plumage is either glossy black, with the hand wings interspersed with white, or matt gray with brown wings. The wings are of medium length, wide in the bird crow and shorter in the bull jay. The tail is of medium length in the thrush crow and long in the bull jay. The medium-length body is egg-shaped with a generally horizontal and crooked posture. The medium-long beak is curved downwards and pointed in the bird crow and bulbous, conical and slightly curved downwards in the bull jay. The jay has a small head and a medium neck, the bull jay has a large head and a thick short neck. The legs are of medium length, the feet are medium to large. The sexes are similar.

Distribution area

A nominate form and another subspecies are distinguished in both the crow and the bullfinch jay:

  • Corcorax melanorhamphos melanorhamphos ( Vieillot , 1817) occurs in eastern Australia to the eastern half of Queensland (south of the Clarke Range region), south to New South Wales (except in the northwest), via Victoria (mainly in the north of the Great Dividing Range) to the Southeast of South Australia (especially in the Mount Lofty Ranges).
  • Corcorax melanorhamphos whiteae Mathews , 1912 occurs on the Eyre Peninsula and in the Mount Lofty Ranges.
  • The distribution area of Struthidea cinerea cinerea Gould , 1837 extends from central and southern Queensland over inner New South Wales, northern Victoria (along the Murray River) to eastern South Australia (mainly north of the Murray River).
  • Struthidea cinerea dalyi Mathews , 1923 occurs in the northern Northern Territory (mainly south of the Roper River) and in north and north-central Queensland in northern Australia.

habitat

The thrush inhabits relatively open woodland from the tropics to the temperate zone of eastern Australia. The black jay prefers drier habitats, which extend to dry bushland in the western part of its range.

food

The diet of mud-nesting crows is different. It consists mainly of insects, arachnids and other invertebrates in the warmer months. Other diets include seeds, small vertebrates, and aquatic invertebrates. The blue crow and the bull jay look for their food for the most part on the ground, with their beaks scouring the leaves, fallen twigs and branches or other material.

Social and reproductive behavior

A bullfinch's mud nest

Both species are monogamous, cooperative breeding birds. They form groups of four to 20 members who help with hatching and rearing young. As with most cooperative breeding birds, the breeding pair is supported by offspring from previous broods. In contrast to other cooperative breeding birds, whose helpers consist mainly of male juveniles, in the mud nesting crows both the male and the female juveniles remain with the group. Both species build deep bowl-shaped or cup-shaped mud nests, which has earned them the common English name Australian mudnesters (mud nest builders ). Grass is worked into the nest walls. The nest is usually on a wide, horizontal branch. Nest building can take several days and the nests can be built at any time of the year. The clutch generally consists of three to five eggs. Both males and females participate in all areas of parental care, including nesting, incubating the eggs, and feeding the young. The incubation of the eggs takes 19 to 20 days and the young leave the nest after another 18 to 30 days. They achieve complete independence from their parents and other group members after about six months.

Systematics

Originally only the two monotypic genera Struthidea Gould , 1837 and Corcorax Lesson , 1831 were assigned to the family:

  • Corcorax Lesson , 1831
    • Bluebird ( Corcorax melanorhamphos ( Vieillot , 1817) )
      • Corcorax melanorhamphos melanorhamphos ( Vieillot , 1817)
      • Corcorax melanorhamphos whiteae Mathews , 1912
  • Struthidea Gould , 1837
    • Bull jay ( Struthidea cinerea Gould , 1837 )
      • Struthidea cinerea cinerea Gould , 1837
      • Struthidea cinerea dalyi Mathews , 1923

Both genera are morphologically so different that they were at times classified into the separate families Corcaracidae and Struthideidae. Gregory Mathews described the family Struthideidae in 1924 and the family Corcaracidae in 1927. While the Handbook of the Birds of the World gives priority to the family Struthideidae and regards Corcaracidae as a junior synonym, both at the International Ornithological Congress and in more recent literature, z. B. David Winkler et al .: Bird Families of the World (Lynx Edicions, 2015) supports the use of the name Corcaracidae. Since Corcorax melanorhamphos is considered a type species of the family, the ICZN decided in 2013 to keep the name Corcaracidae for the family and to specify the correct spelling of the type species with melanorhamphos (instead of melanoramphos ).

The closest relatives of the mud-nesting crows are the birds of paradise (Paradisaeidae), with which they form a common clade together with the representatives of the Melampittidae family .

literature

  • Barker, FK, Cibois, A., Schikler, P., Feinstein, J., Cracraft, J., 2004. Phylogeny and diversification of the largest avian radiation. Proceedings of the National Academy of Sciences of the United States of America 101, pp. 11040-11045.
  • Rowley, I., Russell, E. & Bonan, A .: Australian Mudnesters (Struthideidae). In: del Hoyo, J., Elliott, A., Sargatal, J., & Christie, DA (Eds.). Handbook of the Birds of the World. Volume 14: Bush-shrikes to Old World Sparrows, Lynx Edicions, Barcelona, ​​2009. pp. 272-286.
  • Jønsson, KA, Fabre, P.-H., Ricklefs, RE, Fjeldså, J., 2011. Major global radiation of corvoid birds originated in the proto-Papuan archipelago. Proceedings of the National Academy of Sciences of the United States of America 108, pp. 2328-2333.
  • Marie Aggerbeck, Jon Fjeldså, Les Christidis , Pierre-Henri Fabre, Knud Andreas Jønsson: Resolving deep lineage divergences in core corvoid passerine birds supports a proto-Papuan island origin. In: Molecular Phylogenetics and Evolution 70 (2014), pp. 272-285.
  • David W. Winkler , Shawn M. Billerman & Irby J. Lovette : Bird Families of the World , The CornellLab of Ornithology & Lynx Edicions, Barcelona, ​​2015. ISBN 978-84-941892-0-3 , pp. 350-351

Individual evidence

  1. ↑ Rudolf Berndt, Wilhelm Meise: Natural history of birds: Special ornithological studies , Kosmos, Society of Friends of Nature, Franckh'sche Verlagshandlung, 1962, p. 571
  2. ^ IOC World Bird List
  3. ↑ ICZN Case 3630 Corcaracidae Mathews, 1927 (Aves) and the spelling melanorhamphos Vieillot, 1817 for the valid name of the type species of its type genus: proposed conservation of usage.
  4. ↑ M. Aggerbeck et al. / Molecular Phylogenetics and Evolution 70 (2014) 272-285, see literature

Web links

Commons : Mud-nesting crows (Corcoracidae)  - Collection of images, videos and audio files