Not easily confused with other parrot species, it has a bright crimson crown, green-yellow cheeks, and a distinctive long bill.

The adult female is very similar though sometimes slightly duller than the male; her key distinguishing feature is a white stripe on the wing under-surface.

Found in woodland and open savanna country, the red-capped parrot is predominantly herbivorous, consuming seeds, particularly of eucalypts, as well as flowers and berries, but insects are occasionally eaten.

Although the red-capped parrot has been shot as a pest and has been affected by land clearing, the population is growing and the species is considered of least-concern by the International Union for Conservation of Nature (IUCN).

The species was described in 1820 by Heinrich Kuhl, as Psittacus spurius, from an immature specimen collected at Albany, Western Australia by the Baudin expedition (1801–1803) and deposited at the National Museum of Natural History in Paris.

[2][3] The specific epithet spurius is the Latin adjective meaning "illegitimate", and refers to the markedly different adult and immature plumages (hence appearing unrelated).

[4] Irish naturalist Nicholas Aylward Vigors named the species Platycercus pileatus in 1830 from an adult male specimen that had been acquired by the Zoological Society of London.

[10] The red-capped parrot's elongated bill and its unusual coloration—lack of cheek patches compared with Platycercus—are the main reasons for its placement in its own genus.

[2] Mathews tentatively described a subspecies carteri in 1915 from a specimen collected at Broomehill on the basis of darker upperparts and greener cheeks;[12] it was not considered distinct by later authors.

[13] There is no known geographical variation; five birds from Esperance had smaller bills and tarsi than individuals from elsewhere in its range, but the sample was too small to draw any conclusions.

[16] In 1955, British evolutionary biologist Arthur Cain proposed that the eastern lineage had vanished after being outcompeted by the crimson rosella (Platycercus elegans), and that its closest relative was the horned parakeet (Eunymphicus cornutus) of New Caledonia, which he concluded had adopted a much greener plumage of a wetter climate.

[22] The red-capped parrot has a long bill and bright, clear patterned plumage, variously described as magnificent, gaudy, or clownishly coloured.

The adult male has a crimson forehead and crown, which extends from the gape or base of the lower mandible through the eye and grey-brown lores.

The male has a slightly wider and flatter head, noticeable when birds are compared directly with each other,[14] as well as longer wings and tail.

[32] Nestlings and fledglings up to two weeks post leaving the nest make a high-pitched two-syllable food begging call.

[26] The red-capped parrot occurs in the Southwest Australia ecoregion in dense to open forest and woodland, and heathland in coastal regions.

[31][21] It also occurs around remnant stands of marri conserved as shade trees on farmland in the western Wheatbelt and Swan Coastal Plain.

[27] The parrot is frequently observed at lake reserves in suburban areas on the Swan Coastal Plain, within sight of waders (Charadriiformes) occurring at freshwater to brackish wetlands.

[36] Red-cap parrot is commonly sighted at Two Peoples Bay Nature Reserve and along roadsides around the Stirling Range and Porongorups.

[27] The red-capped parrot is shy, and often retreats to the upper canopy of trees if disturbed,[27] which has made study of its breeding and social behaviour difficult.

[38] The red-capped parrot is thought to be monogamous, pairs forming long-term bonds generally from around 20 months of age.

[38] Marri seeds are the preferred diet, but it also extracts seeds from karri (Eucalyptus diversicolor), woody pear (Xylomelum), Grevillea, Hakea, dryandra (Banksia) and sheoak (Casuarina, Allocasuarina), mangite (Banksia grandis), as well as from grasses, herbs, or shrubs associated with marri-dominated vegetation types.

[47] The fruit of other cultivated introductions are also selected, including almond, nectarine, olive, peaches, plums, pomegranates, and white cedar (Melia azedarach).

[48] The red-capped parrot primarily feeds on the ground, clasping the capsule of eucalypts or cones of sheoak with one foot and extracting the seed with their slender hooked beak.

[21] The dexterity it exhibits using its foot and beak to dislodge seeds is also shown by the long-billed black cockatoo (Calyptorhynchus baudinii).

[52] Species of bird louse recorded on the red-capped parrot include Forficuloecus palmai, Heteromenopon kalamundae and a member of the genus Neopsittaconirmus.

On account of this and its large range, it is considered to be a least-concern species by the International Union for Conservation of Nature (IUCN),[1] though it has declined in the shires north of Perth as marri forests have vanished with urban development.

[55] Its attractive colours make the red-capped parrot a desirable species to keep, although it has a reputation for being anxious in captivity and difficult to breed.

[56] The first record of successful reproduction in captivity was in England, almost simultaneously by two aviculturalists in 1909, the slightly earlier hatching of one brood saw Mr. Astley awarded a medal by the nation's Avicultural Society.