Acanthiza

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Acanthiza
Yellowthornbill.jpg
Striated Thornbill (Acanthiza lineata)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Acanthizidae
Genus: Acanthiza
Vigors & Horsfield, 1827
Type species
Motacilla pusilla [1]
Shaw, 1790
Species

14, see text.

Acanthiza is a genus of passeriform birds, most endemic to Australia, but with two species (A. murina and A. cinerea) restricted to New Guinea. These birds are commonly known as thornbills. They are not closely related to species in the hummingbird genera Chalcostigma and Ramphomicron , which are also called thornbills.

Contents

They are found primarily in Australia and have a thin long beak. Colloquially the thornbill is sometimes referred to as a “tit” by locals, but in reality the Australian continent lacks any true tits, albeit Acanthiza species do show some similarities with tits in their behavior. They have a similar role as small insect-eating birds with titmice and kinglets. [2] Like tits, Thornbills live in small groups foraging amidst trees and shrubs, and feed in a similar manner. Cooperative breeding is recorded from most species except the brown and Tasmanian thornbills. [3]

The habitat preferences of the group vary from dense forest to open saltbush and bluebush plains.

Acanthiza follow a very characteristic undulating path when flying. Their diet is formed essentially of little insects and plant lice that these birds glean from foliage. They are also exceptional acrobats that are easily able to stay head downward like tits do.

The nest of the Acanthiza is a large dome-shaped construction, completely enclosed except for a side hole, just like that of the long-tailed tit; however Acanthiza adds to it an additional room whose function is unknown. It is somewhat similar to the Aegithalidae in combining long incubation periods with highly synchronous hatching. [4] This combination, normally impossible due to intense competition for food, [5] occurs because parents and (usually) helpers can organise food supply in such a manner that sibling competition for food is virtually absent. [6]

The number of eggs usually ranges from two to four, and the incubation period is around twenty days with laying intervals of two days. The length of an adult bird is 8 to 10 centimetres (3.1 to 3.9 in).

Species

The genus contains 14 species: [7]

ImageCommon NameScientific nameDistribution
Mountain thornbill Acanthiza katherinanorth-east Queensland, Australia
Acanthiza pusilla - Risdon Brook.jpg Brown thornbill Acanthiza pusillasouth-eastern Australia, Tasmania
Inland thornbill 0A2A2135.jpg Inland thornbill Acanthiza apicalisAustralia, New Guinea
Tasmanian Thornbill - Tasmania S4E5890 (22399609731).jpg Tasmanian thornbill Acanthiza ewingiiTasmania and the Bass Strait Islands.
New Guinea thornbill Acanthiza murinaNew Guinea
Chestnut-rumped Thornbill, on branch.jpg Chestnut-rumped thornbill Acanthiza uropygialisAustralia.
Acanthiza reguloides.jpg Buff-rumped thornbill Acanthiza reguloidesEastern Australia.
Western thornbill Acanthiza inornatasouthwestern Australia.
Slender-billed thornbill Acanthiza iredaleiAustralia.
Acanthiza chrysorrhoa -Canberra, Australia-8 (2).jpg Yellow-rumped thornbill Acanthiza chrysorrhoasouthern and eastern Australia as well as Tasmania
Acanthiza nana - Wianamatta Reserve.jpg Yellow thornbill Acanthiza nanaeastern coast of Australia.
Grey thornbill Acanthiza cinereaNew Guinea
Acanthiza lineata - Wianamatta Reserve.jpg Striated thornbill Acanthiza lineataAustralia
Slaty-backed Thornbill - Christopher Watson (cropped).jpg Slaty-backed thornbill Acanthiza robustirostrisAustralia.

References

  1. "Acanthizidae". aviansystematics.org. The Trust for Avian Systematics. Retrieved 2023-07-16.
  2. Bell, Harry L.; Ford, Hugh A. (1986). "A Comparison of the Social Organization of Three Syntopic Species of Australian Thornbill, Acanthiza". Behavioral Ecology and Sociobiology. 19 (6): 381–92. Bibcode:1986BEcoS..19..381B. doi:10.1007/bf00300540. JSTOR   4599974. S2CID   6197201.
  3. Higging, P.J. and J.M. Peter; Handbook of Australian, New Zealand and Antarctic Birds , vol. 6: Pardalotes to Shrike-thrushes. ISBN   0-19-553762-9
  4. Ricklefs, R.E.; “Sibling competition, hatching asynchrony, incubation period, and lifespan in altricial birds”; in Power, Dennis M. (editor); Current Ornithology. Vol. 11. ISBN   9780306439902
  5. Losdat, Sylvain, Helfenstein, Fabrice, Gaude, Benoît and Richner, Heinz; “Effect of sibling competition and male carotenoid supply on offspring condition and oxidative stress”
  6. Ricklefs, Robert E.; “SIBLING COMPETITION AND THE EVOLUTION OF BROOD SIZE AND DEVELOPMENT RATE IN BIRDS”
  7. Gill, Frank; Donsker, David, eds. (2019). "Bristlebirds, pardalotes, Australasian warblers". World Bird List Version 9.1. International Ornithologists' Union. Retrieved 21 January 2019.