Perruche de Latham

Identification

The swift parrot is about 25 centimetres (10 in) 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.

Taxonomie

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.<p>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.<p>"Swift parrot" has been designated the official common name by the International Ornithologists' Union (IOC).

Nom scientifique

Lathamus discolor

Autorité

(Shaw, 1790)

Ordre

Psittaciformes

Famille

Psittaculidés

Genre

Lathamus

Répartition et habitat

Genetic evidence has shown that the swift parrot is a single, genetically mixed and nomadic population that moves around the landscape each year. 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. 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. 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. 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, 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.<p>BirdLife International has identified the following sites as being important for swift parrots: Usually inhabiting: forests, woodlands, agricultural land and plantations, and also in urban areas.

Aire de reproduction

AU : e Tasmania (se Australia)

Aire hors reproduction

se QLD to c VIC (se Australia)

Migration

Complete migrants

Conservation

Modelling of demographic data predicted that the swift parrot is Critically Endangered. Further modelling showed that other aspects of their life history (sex ratio bias and shared paternity) makes their population declines worse than originally predicted. Genetic evidence showed there is only one swift parrot population, so threats at different times and places can potentially act on the entire population. Although expert opinion has estimated the species population size as approximately 2,000 individuals, extensive genetic evidence suggests this is overly optimistic, and that the (minimum) census size of the population may be around 300–500 individuals. Severe deforestation of their breeding range has been long recognised as the principal threat to the species. Logging has already had severe impacts on habitat availability in recent decades 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. Deforestation also affects the rate of predation by sugar gliders – where mature forest cover is diminished, parrots suffer worse predation rates. Sugar glider predation is worst where logging is severe; these threats interact in a synergistic manner.<p>Given the severity of deforestation across the breeding range, and the relationship between deforestation and sugar glider predation intensity, 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. <p>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.<p>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.<p>The swift parrot is listed as threatened on the Victorian Flora and Fauna Guarantee Act (1988). Under this Act, an Action Statement for the recovery and future management of this species has been prepared.

Tendance de la population

declining