As a result, it is set to be listed as endangered under the threatened fauna of Australia. Between 28 and 36 per cent of the species' distribution was impacted by the fires. In July 2021, an Australian Department of the Environment and Energy spokesperson stated the population has declined by approximately 69% in the last three generations, or 21 years and in addition to this decline, the species has suffered direct mortality and habitat loss during the 2019–20 Australian bushfire season. Habitat is defined to include 'an area periodically or occasionally occupied by a species'. Damage is defined to include 'damage caused by removing any part of the habitat'. This protection status as a threatened species makes it a Tier 1 criminal offence for a person or corporation to knowingly damage the bird's habitat. It is protected as a vulnerable species under the Biodiversity Conservation Act 2016 (NSW). As a result, the gang-gang is now listed as vulnerable in New South Wales. Loss of older, hollow trees and loss of feeding habitat across south-eastern Australia through land clearing has led to a significant reduction in the numbers of this cockatoo in recent years. Also, they breed in the canopy of most trees. Unlike most other cockatoos, gang-gangs nest in young, solid trees, the females using their strong beaks to excavate nesting cavities. They migrate short distances during winter into more open habitats, but must migrate back to denser forests to breed, because they need tall trees in order to build nests. Gang-gangs prefer forests and woodlands in the mountains, with dense shrub understories. They are an introduced species on Kangaroo Island. They used to inhabit King Island off of Tasmania, but have become extinct there.

Gang-gangs are endemic to coastal regions of south-eastern Australia. Gang-gangs are very social birds, but not overly noisy. The birds are not easily mistaken for other cockatoos, but while in flight may resemble the Galah. Juvenile males can be distinguished by their brighter crowns and shorter crests, but otherwise look similar to the adult female. The edges of feathers on upperarts are slightly paler grey than the rest of the feather, which makes the bird look somewhat barred. The edges of feathers in underparts have edges of yellow or pink. The head and crest is bright red in males, but dark grey in females. However, more recent molecular phylogenetic analysis places it in the Cacatuinae clade, not the Calyptorhynchinae, and having diverged from the palm cockatoo ( Probosciger aterrimus). The gang-gang cockatoo was thought to be a distinctive early offshoot of the Calyptorhynchinae (black) cockatoos. The classification of the gang-gang cockatoo has always been controversial due to the unusual appearance and coloration of the bird, especially its sexual dichromatism. The species is monotypic: no subspecies are recognised. The genus name combines the Ancient Greek kallos meaning 'beauty' and kephalē meaning 'head'. The specific epithet is from Latin fimbriata meaning 'fringed'. The type locality is the Bass River in the state of Victoria. The gang-gang cockatoo is now the only species placed in the genus Callocephalon that was introduced in 1837 by the French naturalist René Lesson. Grant coined the binomial name Psittacus fimbriatus. In 1803 the British Royal Navy officer James Grant included an illustration of the gang-gang cockatoo in his book describing a voyage to the colony of New South Wales in Australia. The name gang-gang comes from a New South Wales Aboriginal language, probably from one of the coastal languages, although possibly from Wiradjuri. It is easily identified by its distinctive call, which is described as resembling a creaky gate, or the sound of a cork being pulled from a wine bottle. The gang-gang cockatoo is the faunal emblem of the Australian Capital Territory. It ranges throughout south-eastern Australia.

Mostly mild grey in colour with some lighter scalloping (more pronounced and buffy in females), the male has a red head and crest, while the female has a small fluffy grey crest.

It is the only species placed in the genus Callocephalon. The gang-gang cockatoo ( Callocephalon fimbriatum) is a parrot found in the cooler and wetter forests and woodlands of Australia, particularly alpine bushland.

Are gang gang cockatoos endangered