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, 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. Genetic evidence for the effective population size suggests that the minimum potential population size is now fewer than 300 individual swift parrots. 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.
Habitat for the critically endangered swift parrot is being “knowingly destroyed” by logging because of government failures to manage the species’ survival. 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. 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.
Taxonomy
The surgeon John White described the swift parrot in 1790 as the red-shouldered paroquet (Psittacus discolor). 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.
"Swift parrot" has been designated the official common name by the International Ornithologists' Union (IOC).
Description
The swift parrot is about long and has long pointed wings and long tapering tail feathers. 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. 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.
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. Tree cavities with these traits are rare and comprise only 5% of the available cavities in Tasmanian forests. These cavities are more likely to occur in large trees. These characteristics of tree cavities are important for passive defense of their nests against native Tasmanian predators. 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). 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. The local extent of deforestation is also positively correlated with other threats to the parrots like predation by sugar gliders.
