Biology:Western grasswren

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Short description: Species of bird

Western grasswren
Amytornis textilis - Thick-billed Grasswren.jpg
Scientific classification edit
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Maluridae
Genus: Amytornis
Species:
A. textilis
Binomial name
Amytornis textilis
(Quoy & Gaimard, 1824)[2]
Subspecies

See text

The western grasswren (Amytornis textilis), also referred to as the thick-billed grasswren (western subspecies) and, formerly, as the textile wren, is a species of bird in the family Maluridae. It is endemic to Australia . It was formerly lumped as the nominate subspecies of the thick-billed grasswren.[3]

History

The species, indeed the genus, was first collected in 1818 on Shark Bay’s Peron Peninsula, in northwest Western Australia, by Jean René Constant Quoy and Joseph Paul Gaimard, naturalists with Louis de Freycinet's circumnavigational exploring expedition in the French corvette Uranie. Although the original specimen was apparently lost with the shipwreck of the Uranie in the Falkland Islands, it had been illustrated by expedition artist Jacques Arago and was described (as Malurus textilis) by Charles Dumont in 1824.[2]

Description

A species of Amytornis, the western grasswren is a small, shy, mainly terrestrial bird. It has brown plumage, finely streaked with black and white, and a long, slender tail. Males are slightly larger than females, with adult males weighing 22–27 g and females 20–25 g. Females develop distinctive chestnut patches on their flanks beneath their wings at 1–2 months old. They are usually found in groups of two or three.[4]

Subspecies

Recognised subspecies are:[2][3]

  • Amytornis textilis textilis (Dumont, 1824) – (Shark Bay, WA)
  • A. textilis macrourus (Gould, 1847) – (formerly Southwest Australia, now extinct)
  • A. textilis myall (Mathews, 1916) – (Gawler Ranges, SA)

Other described subspecies of doubtful validity include:[2]

  • A. textilis carteri (Mathews, 1917) – (Dirk Hartog Island, now extinct)
  • A. textilis gigantura (Milligan, 1901) – (northern inland population of arid zone chenopod shrublands, now extinct)

Distribution and habitat

Nest and eggs photographed by F. L. Whitlock, East Murchison district

The species once occurred through much of southwestern Australia, with an outlying subspecies in the Gawler Ranges of South Australia. The range of the nominate subspecies, which used to inhabit inland locations, has contracted westwards to the Shark Bay region since 1910. The cause is probably the decline in habitat quality resulting from overgrazing, which has reduced the availability of cover and nesting sites. Its preferred habitat is low, often Acacia dominated, semiarid shrubland, no more than a metre in height, that forms densely foliaged clumps and thickets.[4]

The Southwest Australian subspecies (A. t. macrourus) is now extinct. Its preferred habitat was dense thickets within a variety of eucalypt communities.[2]

Status and conservation

The population size of the nominate subspecies (A. t. textilis) has been estimated at 21,500 individuals occurring over an area of 20,000 km2, with an area of occupancy of 1200 km2. The population comprises a large subpopulation within Francois Peron National Park and a second subpopulation consisting of several disjunct groups on nearby pastoral lands. Individuals from both populations were reintroduced to Dirk Hartog Island in 2022.[5] The generation length has been estimated at four years. Although the subspecies has suffered a severe reduction in range and population decline in the past, the remaining population is healthy and stable, and is not considered eligible for listing under Australia's Environment Protection and Biodiversity Conservation Act 1999 (EPBC).[4]

The Gawler Ranges subspecies (A. t. myall) has an estimated population of about 8400 mature individuals, with a range area of 12,000 km2 and an area of occupancy of 600 km2. Its generation length has been estimated at 9.7 years and the population trend is one of decrease.[6]

References

  1. BirdLife International (2017). "Amytornis textilis". IUCN Red List of Threatened Species 2017: e.T103684117A118653536. doi:10.2305/IUCN.UK.2017-3.RLTS.T103684117A118653536.en. https://www.iucnredlist.org/species/103684117/118653536. Retrieved 13 November 2021. 
  2. 2.0 2.1 2.2 2.3 2.4 Black, Andrew (2011). "Western Australia, home of the Grass-Wren (Amytornis textilis)". Amytornis: Western Australian Journal of Ornithology 3: 1–12. http://www.birdlife.org.au/images/uploads/branches/documents/WA-Amytornis3_2011_Black_pp1-12.pdf. 
  3. 3.0 3.1 Black A.B.; Joseph L.; Pedler L.P.; Carpenter G.A. (2010). "A taxonomic framework for interpreting evolution within the Amytornis textilis–modestus complex of grasswrens". Emu 110 (4): 358–363. doi:10.1071/mu10045. 
  4. 4.0 4.1 4.2 "Advice to the Minister for the Environment and Heritage from the Threatened Species Scientific Committee (the Committee) on Amendments to the list of Threatened Species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)". Dept of Environment and Heritage, Australia. http://www.environment.gov.au/biodiversity/threatened/species/pubs/amytornis-textilis-textilis.pdf. 
  5. "Rare grasswren returns to island for first time in a century" (in en-AU). ABC News. 2022-11-19. https://www.abc.net.au/news/2022-11-19/western-grasswren-returned-to-dirk-hartog-island/101670484. 
  6. Stephen Garnett; Judit Szabo (2011). "Western Grasswren (Gawler Ranges)". Action Plan for Australian Birds 2010. CSIRO. http://birdsindanger.net/western-grasswren-gawler-ranges. 

Wikidata ☰ Q1210117 entry