Biology:Swift parrot

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Short description: Critically endangered species of Australian bird

Swift parrot
Swift Parrot.jpg
A visiting migrant in Canberra, Australian Capital Territory
Scientific classification edit
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Psittaciformes
Family: Psittaculidae
Tribe: Platycercini
Genus: Lathamus
Lesson, 1830
Species:
L. discolor
Binomial name
Lathamus discolor
(Shaw, 1790)
Swift Parrot Range.png
Distribution of the swift parrot
From Atlas of Living Australia
Synonyms[2]

Psittacus discolor Shaw, 1790
Psittacus sanguinolentus Kerr, 1792
Psittacus lathami Bechstein, 1811
Psittacus humeralis Bechstein, 1811
Psittacus banksianus Vieillot, 1818
Psittacus australis Kuhl 1820
Lathamus rubrifrons Lesson, 1830

The swift parrot (Lathamus discolor) is a species of broad-tailed parrot, found only in southeastern Australia. The species breeds in Tasmania during the summer and migrates north to south eastern mainland Australia from Griffith-Warialda in New South Wales and west to Adelaide in the winter. It is a nomadic migrant, and it settles in an area only when there is food available. The Swift Parrot was voted 2023 Bird of the Year in The Guardian Australia and BirdLife Australia’s biennial poll.

The species is critically endangered,[3][4] and the severe predation of introduced sugar gliders (Petaurus breviceps) on breeding females and nests in some locations has demonstrated an unexpected but potentially serious new threat. Sugar glider predation is worst where logging is severe; these threats interact in a synergistic manner.[5] Genetic evidence for the effective population size suggests that the minimum potential population size is now fewer than 300 individual swift parrots.[6] The genetic evidence supports the results of earlier studies that use demographic information about swift parrots to show the species could be extinct by 2031.[3][7]

Habitat for the critically endangered swift parrot is being “knowingly destroyed” by logging because of government failures to manage the species’ survival.[8] Matthew Webb and Dejan Stojanovic, two of the Eureka prize finalists from the Australian National University’s Difficult Bird Research Group, say governments have stalled on management plans that would protect known feeding and nesting habitat in Tasmania.[9] The researchers analysed logging in Tasmania’s southern forests during the 20-year course of the previous regional forest agreement. They found that a third of the eucalypt forest in this area had been logged between 1997 and 2016 and a quarter of old growth trees that provide nesting habitat for swift parrots had been cleared. “It is very clear that critical breeding habitat is being logged and that current logging regimes are not sustainable,” the paper states.[8]

Taxonomy

The surgeon John White described the swift parrot in 1790 as the red-shouldered paroquet (Psittacus discolor).[10] It was placed in the genus Lathamus by René Primevère Lesson in 1830.

A 2011 genetic study including nuclear and mitochondrial DNA found that the swift parrot was an early offshoot from a lineage giving rise to the genera Prosopeia, Eunymphicus and Cyanoramphus, diverging around 14 million years ago.[11]

"Swift parrot" has been designated the official common name by the International Ornithologists' Union (IOC).[12]

Description

The swift parrot is about 25 centimetres (10 in) long and has long pointed wings and long tapering tail feathers.[13] It is mainly green with bluish crown and red on the face above and below the beak. The adult female is slightly duller, and the juvenile has a dark brown iris and a pale orange bill.[14] The forehead to throat is crimson and there is also crimson patch at the top, edge of the wing. They are noisy, always active and showy, and are very fast with their direct flight.[15]

Breeding

The species breeds in Tasmania from September to February. It nests in tree cavities, but is highly selective in the types of cavities it uses as nests. It prefers cavities with small entrances, deep chambers and wide floors.[16] Tree cavities with these traits are rare and comprise only 5% of the available cavities in Tasmanian forests.[16] These cavities are more likely to occur in large trees.[17] These characteristics of tree cavities are important for passive defense of their nests against native Tasmanian predators.[18] Tree cavities suitable for nesting are highly vulnerable to disturbance. Wildfire caused the collapse of 62.8% of known swift parrot nest cavities (and 48.6% of nesting trees).[19] Deforestation (primarily driven by native forest logging) has been an important contemporary cause of habitat loss for swift parrots. In just one area of swift parrot breeding habitat, the southern forests, 33% of total forest cover was lost/disturbed by logging between 1996–2016, and 23% of potential swift parrot nesting habitat was logged over this same time period.[4] The local extent of deforestation is also positively correlated with other threats to the parrots like predation by sugar gliders.[5]

A juvenile swift parrot in Tasmania.

Swift parrots select where to breed in Tasmania based on the local availability of both food and nesting sites.[20][21] The parrots settle wherever in Tasmania their preferred food (nectar from flowering Eucalyptus globulus and Eucalyptus ovata) is abundant, but birds can only breed where suitable nesting sites are also available nearby.[21] Because swift parrots prefer to breed in the most resource rich patch of food, they are able to rear their nestlings in the 'best' conditions each year.[22] Successful swift parrot nests have a mean clutch sizes of 3.8 eggs, and produce 3.2 fledglings, equating to breeding success of 86.9%.[22] However sugar gliders, which are introduced to Tasmania,[23] are a major nest predator of swift parrots.[5] Sugar gliders can result in locally severe parrot nesting failure, and there is a positive relationship between the severity of glider predation and land-cover of mature forest within 500m of a swift parrot nest.[5] This relationship means that in locations where forest cover is low and disturbed, nest failure of swift parrots can be as high as 100%.[5] Sugar gliders are tolerant of forest disturbance, and have high rates of occupancy of swift parrot habitat in Tasmania.[24] On offshore islands where sugar gliders are absent, swift parrots have higher breeding success.[5]

Distribution

Genetic evidence has shown that the swift parrot is a single, genetically mixed and nomadic population that moves around the landscape each year.[25] Because they are nomadic, swift parrots can occur across a very large potential area, but settlement at a given location depends on the local availability of food.[20][26] However, in the Tasmanian breeding range, swift parrots need both food and suitable nesting sites to occur in close proximity in order to nest at a given site.[21] The swift parrot migrates each year across Bass Strait between Tasmania and the mainland of Australia. They arrive in Tasmania during September and return to south-eastern Australia during March and April.[15] They can be found as far north as south-eastern Queensland and as far west as Adelaide in South Australia, although recent sightings have been restricted to the south-eastern part of the state. Because swift parrots are nomadic migrants,[20] their occurrence at any one location are difficult to predict. Although they will repeatedly return to the same locations, local occurrence may only happen intermittently depending on whether or not food (flowering trees) is available in a given year.[20]

Important Bird Areas

Swift Lorikeet (Lathamus discolor) illustrated by Elizabeth Gould (1804–1841) for John Gould’s (1804–1881) Birds of Australia (1972 Edition, 8 volumes).

BirdLife International has identified the following sites as being important for swift parrots:[27]

New South Wales
  • Brisbane Water
  • Capertee Valley
  • Hastings-Macleay
  • Hunter Valley
  • Lake Macquarie
  • Richmond Woodlands
  • South-west Slopes of NSW
  • Tuggerah
  • Ulladulla to Merimbula
Victoria
  • Bendigo Box-Ironbark Region
  • Maryborough-Dunolly Box-Ironbark Region
  • Puckapunyal
  • Rushworth Box-Ironbark Region
  • St Arnaud Box-Ironbark Region
  • Warby-Chiltern Box-Ironbark Region
Tasmania
  • Bruny Island
  • Maria Island
  • South-east Tasmania

Habitat

File:Swift Parrot.ogv

Usually inhabiting: forests, woodlands, agricultural land and plantations, and also in urban areas.

Diet

Swift parrots are primarily nectar feeders, preferring nectar from flowering Eucalyptus spp. In Tasmania, their settlement of breeding habitat is regulated by the occurrence of flowering in their two main food trees Eucalyptus globulus and Eucalyptus ovata.[20] In the winter, their habitat use is broader, with foraging occurring on a range of flowering Eucalyptus spp. across southeastern mainland Australia.[26][28]

Conservation status

Modelling of demographic data predicted that the swift parrot is Critically Endangered.[3] Further modelling showed that other aspects of their life history (sex ratio bias and shared paternity) makes their population declines worse than originally predicted.[7] Genetic evidence showed there is only one swift parrot population, so threats at different times and places can potentially act on the entire population.[25] Although expert opinion has estimated the species population size as approximately 2,000 individuals,[29] recent genetic evidence suggests this is overly optimistic, and that the (minimum) census size of the population may be lower than 300 individuals.[6] Severe deforestation of their breeding range has been long recognised as the principal threat to the species.[30] Logging has already had severe impacts on habitat availability in recent decades[4] and there is evidence that up to 23% of swift parrot breeding habitat has been logged just in the Southern Forests region of Tasmania over the last 20 years.[4] Deforestation also affects the rate of predation by sugar gliders – where mature forest cover is diminished, parrots suffer worse predation rates.[5]

Given the severity of deforestation across the breeding range,[4] and the relationship between deforestation and sugar glider predation intensity,[5] habitat loss in critical breeding areas of Tasmania may be the species most severe threat. Unfortunately, there is evidence that weak and ineffective policy for protection of threatened species in Tasmania's logged forests is likely to continue to threaten the swift parrot into the future.[31]

Australia

Swift parrots are listed as Endangered on the Australian Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), which has been criticised for failing to protect them and other threatened species.[32]

Victoria

The swift parrot is listed as threatened on the Victorian Flora and Fauna Guarantee Act (1988).[33] Under this Act, an Action Statement for the recovery and future management of this species has been prepared.[34]

  • On the 2007 advisory list of threatened vertebrate fauna in Victoria, the swift parrot was listed as Endangered.[35]

References

  1. BirdLife International (2018). "Lathamus discolor". IUCN Red List of Threatened Species 2018: e.T22685219A130886700. doi:10.2305/IUCN.UK.2018-2.RLTS.T22685219A130886700.en. https://www.iucnredlist.org/species/22685219/130886700. Retrieved 12 November 2021. 
  2. Australian Biological Resources Study (7 October 2015). "Species Lathamus discolor (Shaw, 1790)". Australian Faunal Directory. Canberra, Australian Capital Territory: Department of the Environment, Water, Heritage and the Arts, Australian Government. https://biodiversity.org.au/afd/taxa/Lathamus_discolor. 
  3. 3.0 3.1 3.2 Heinsohn, Robert; Webb, Matthew; Lacy, Robert; Terauds, Aleks; Alderman, Rachael; Stojanovic, Dejan (2015-06-01). "A severe predator-induced population decline predicted for endangered, migratory swift parrots (Lathamus discolor)" (in en). Biological Conservation 186: 75–82. doi:10.1016/j.biocon.2015.03.006. ISSN 0006-3207. http://www.sciencedirect.com/science/article/pii/S000632071500110X. 
  4. 4.0 4.1 4.2 4.3 4.4 Webb, Matthew H.; Stojanovic, Dejan; Heinsohn, Robert (2019-06-18). "Policy failure and conservation paralysis for the critically endangered swift parrot" (in en). Pacific Conservation Biology 25 (2): 116–123. doi:10.1071/PC18020. ISSN 2204-4604. https://www.publish.csiro.au/pc/PC18020. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Stojanovic, Dejan; Webb, Matthew H.; Alderman, Rachael; Porfirio, Luciana L.; Heinsohn, Robert (2014). "Discovery of a novel predator reveals extreme but highly variable mortality for an endangered migratory bird" (in en). Diversity and Distributions 20 (10): 1200–1207. doi:10.1111/ddi.12214. ISSN 1472-4642. 
  6. 6.0 6.1 Olah, G.; Stojanovic, D.; Webb, M. H.; Waples, R. S.; Heinsohn, R. (2020). "Comparison of three techniques for genetic estimation of effective population size in a critically endangered parrot" (in en). Animal Conservation 24 (3): 491–498. doi:10.1111/acv.12655. ISSN 1469-1795. 
  7. 7.0 7.1 Heinsohn, Robert; Olah, George; Webb, Matthew; Peakall, Rod; Stojanovic, Dejan (2019). "Sex ratio bias and shared paternity reduce individual fitness and population viability in a critically endangered parrot" (in en). Journal of Animal Ecology 88 (4): 502–510. doi:10.1111/1365-2656.12922. ISSN 1365-2656. PMID 30511387. 
  8. 8.0 8.1 Webb, Matthew H.; Stojanovic, Dejan; Heinsohn, Robert (2018-07-17). "Policy failure and conservation paralysis for the critically endangered swift parrot" (in en). Pacific Conservation Biology 25 (2): 116–123. doi:10.1071/PC18020. ISSN 2204-4604. https://www.publish.csiro.au/pc/PC18020. 
  9. "Logging 'destroying' swift parrot habitat as government delays action" (in en). 2018-07-25. http://www.theguardian.com/environment/2018/jul/26/logging-destroying-swift-parrot-habitat-as-government-delays-action. 
  10. White, John (1790). Journal of a Voyage to New South Wales with Sixty-five Plates of Non-descript Animals, Birds, Lizards, Serpents, Curious Cones of Trees and Other Natural Productions. Debrett. pp. 263. https://archive.org/details/b28408160. 
  11. Joseph, Leo; Toon, Alicia; Schirtzinger, Erin E.; Wright, Timothy F. (2011-06-01). "Molecular systematics of two enigmatic genera Psittacella and Pezoporus illuminate the ecological radiation of Australo-Papuan parrots (Aves: Psittaciformes)" (in en). Molecular Phylogenetics and Evolution 59 (3): 675–684. doi:10.1016/j.ympev.2011.03.017. ISSN 1055-7903. PMID 21453777. http://www.sciencedirect.com/science/article/pii/S1055790311001564. 
  12. Gill, Frank; Donsker, David, eds (2021). "Parrots, Cockatoos". World Bird List Version 11.2. International Ornithologists' Union. https://www.worldbirdnames.org/new/bow/parrots/. 
  13. Pizzey, Graham (Graham Martin), 1930- (1997). The Graham Pizzey & Frank Knight field guide to the birds of Australia. Knight, Frank, 1941-. Pymble, N.S.W.: HarperCollins. ISBN 0-207-19691-5. OCLC 677260679. https://www.worldcat.org/oclc/677260679. 
  14. "Swift Parrot - BirdLife Species Factsheet". BirdLife International. 2008. http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=1488&m=0. 
  15. 15.0 15.1 Forshaw, Joseph Michael. (2006). Parrots of the world : an identification guide. Princeton, N.J.: Princeton University Press. ISBN 0-691-09251-6. OCLC 57893782. https://www.worldcat.org/oclc/57893782. 
  16. 16.0 16.1 Stojanovic, Dejan; Webb, Matthew; Roshier, David; Saunders, Debra; Heinsohn, Robert (2012-12-01). "Ground-based survey methods both overestimate and underestimate the abundance of suitable tree-cavities for the endangered Swift Parrot". Emu - Austral Ornithology 112 (4): 350–356. doi:10.1071/MU11076. ISSN 0158-4197. https://doi.org/10.1071/MU11076. 
  17. Webb, Matthew H.; Holdsworth, Mark C.; Webb, Janneke (2012-09-01). "Nesting requirements of the endangered Swift Parrot (Lathamus discolor)". Emu - Austral Ornithology 112 (3): 181–188. doi:10.1071/MU11014. ISSN 0158-4197. https://doi.org/10.1071/MU11014. 
  18. Stojanovic, Dejan; Rayner, Laura; Webb, Matthew; Heinsohn, Robert (2017-07-03). "Effect of nest cavity morphology on reproductive success of a critically endangered bird". Emu - Austral Ornithology 117 (3): 247–253. doi:10.1080/01584197.2017.1311221. ISSN 0158-4197. https://doi.org/10.1080/01584197.2017.1311221. 
  19. Stojanovic, Dejan; Webb nee Voogdt, Janneke; Webb, Matthew; Cook, Henry; Heinsohn, Robert (2016-01-15). "Loss of habitat for a secondary cavity nesting bird after wildfire" (in en). Forest Ecology and Management. Special Section: Forest Management for Climate Change 360: 235–241. doi:10.1016/j.foreco.2015.10.040. ISSN 0378-1127. http://www.sciencedirect.com/science/article/pii/S0378112715005976. 
  20. 20.0 20.1 20.2 20.3 20.4 Webb, Matthew H.; Wotherspoon, Simon; Stojanovic, Dejan; Heinsohn, Robert; Cunningham, Ross; Bell, Phil; Terauds, Aleks (2014-08-01). "Location matters: Using spatially explicit occupancy models to predict the distribution of the highly mobile, endangered swift parrot" (in en). Biological Conservation 176: 99–108. doi:10.1016/j.biocon.2014.05.017. ISSN 0006-3207. http://www.sciencedirect.com/science/article/pii/S0006320714002055. 
  21. 21.0 21.1 21.2 Webb, Matthew H.; Terauds, Aleks; Tulloch, Ayesha; Bell, Phil; Stojanovic, Dejan; Heinsohn, Robert (2017). "The importance of incorporating functional habitats into conservation planning for highly mobile species in dynamic systems" (in es). Conservation Biology 31 (5): 1018–1028. doi:10.1111/cobi.12899. ISSN 1523-1739. PMID 28130909. 
  22. 22.0 22.1 Stojanovic, Dejan; Terauds, Aleks; Westgate, Martin J.; Webb, Matthew H.; Roshier, David A.; Heinsohn, Robert (2015). Griffith, Simon. ed. "Exploiting the richest patch has a fitness pay-off for the migratory swift parrot" (in en). Journal of Animal Ecology 84 (5): 1194–1201. doi:10.1111/1365-2656.12375. PMID 25973857. 
  23. Campbell, Catriona D.; Sarre, Stephen D.; Stojanovic, Dejan; Gruber, Bernd; Medlock, Kathryn; Harris, Stephen; MacDonald, Anna J.; Holleley, Clare E. (2018). "When is a native species invasive? Incursion of a novel predatory marsupial detected using molecular and historical data" (in en). Diversity and Distributions 24 (6): 831–840. doi:10.1111/ddi.12717. ISSN 1472-4642. 
  24. Allen, Mark; Webb, Matthew H.; Alves, Fernanda; Heinsohn, Robert; Stojanovic, Dejan (2018). "Occupancy patterns of the introduced, predatory sugar glider in Tasmanian forests" (in en). Austral Ecology 43 (4): 470–475. doi:10.1111/aec.12583. http://doi.wiley.com/10.1111/aec.12583. 
  25. 25.0 25.1 Stojanovic, D.; Olah, G.; Webb, M.; Peakall, R.; Heinsohn, R. (2018). "Genetic evidence confirms severe extinction risk for critically endangered swift parrots: implications for conservation management" (in en). Animal Conservation 21 (4): 313–323. doi:10.1111/acv.12394. ISSN 1469-1795. 
  26. 26.0 26.1 Saunders, Debra L.; Heinsohn, Robert (2008-03-01). "Winter habitat use by the endangered, migratory Swift Parrot (Lathamus discolor) in New South Wales". Emu - Austral Ornithology 108 (1): 81–89. doi:10.1071/MU07033. ISSN 0158-4197. https://doi.org/10.1071/MU07033. 
  27. "BirdLife International" (in en-GB). https://www.birdlife.org/. 
  28. Kennedy, Simon J.; Tzaros, Christopher L. (2005). "Foraging ecology of the Swift Parrot Lathamus discolor in the box-ironbark forests and woodlands of Victoria" (in en). Pacific Conservation Biology 11 (3): 158–173. doi:10.1071/pc050158. ISSN 2204-4604. https://www.publish.csiro.au/pc/pc050158. 
  29. Garnett ST, Szabo JK,Dutson G. (2011) Action Plan for Australian Birds 2010. CSIRO, Melbourne
  30. Saunders DL,Tzaros C (2011) National Recovery Plan for the Swift Parrot Lathamus discolor. Birds Australia, Melbourne
  31. "Pulling a Swiftie". https://www.et.org.au/pulling_a_swiftie. 
  32. Wiggins, Nick; Phillips, Keri (24 August 2020). "What this critically endangered bird tells us about Australia's failing environment protection laws". https://www.abc.net.au/news/2020-08-25/environment-protection-laws-fail-swift-parrot-conservationists/12574398. 
  33. Department of Sustainability and Environment, Victoria
  34. Department of Sustainability and Environment, Victoria
  35. Victorian Department of Sustainability and Environment (2007). Advisory List of Threatened Vertebrate Fauna in Victoria - 2007. East Melbourne, Victoria: Department of Sustainability and Environment. p. 15. ISBN 978-1-74208-039-0. 

Further reading

Recent research findings

The swift parrot has been studied since 2009 by the Difficult Bird Research Group at the Fenner School of Environment and Society of The Australian National University. Below are their research findings:

External links

Wikidata ☰ Q1260561 entry