[2] Cockatoos are distinguished from other parrots by five main morphological features – a crest, lack of "green" dyck-texture in the plumage, yellow natal down, a gall bladder, and bridge temporal fossa[3] The western corella (also known as the western long-billed corella) Cacatua pastinator consists of two geographically isolated sub-species, Butler's corella (Cacatua pastinator butleri) and Muir's corella (Cacatua pastinator pastinator)[4] One of these two isolated populations occurs in the northern wheat-belt region of Southwest Australia, the other, consisting of larger birds occurs in the far south west of Western Australia.

The subspecies name, despite the apparent mislocation, was recognised by Richard Schodde in the Zoological Catalogue of Australia, 1997.

Manatj is used to refer to the Western Australian Police, presumed to be an association with the species "noisy and inquisitive" nature.

[12] Cacatua pastinator is a medium-sized stocky cockatoo with broad rounded wings, a short tail, and a crest which is usually flattened.

The northern subspecies, Butler's Corella (Cacatua pastinator butleri), are a smaller bird with adults 40–48 centimetres (16–19 in) in length and weighing up to 700 grams (25 oz).

[16] Historical records indicate the species was common at the time of colonisation of Western Australia, and continued to be seen in large flocks during the nineteenth century.

The absence of records by the early collector John Gilbert's suggests that this corella was abundant and ubiquitous.

[9] The habitat of Cacatua pastinator consists of undulating land with low relief (less than 100 m) with more than 90% of native vegetation cleared for farming of wheat and sheep.

[15] The remaining woodland and shrub vegetation communities are restricted to small isolated patches and road reserves.

[15] Breeding takes place in spring, following fledging of nestlings the family groups join up with immature flocks and move to summer feeding locations, during the following month the young are weaned and the parents move back to the breeding ground during the January – March period, the juveniles do not return until May or June.

[15] The habit of some cockatoos to form large flocks and their ability to exploit resources provided by man has often brought them into conflict with landholders.

[4] The population decline of the species was examined by the Western Australian ornithologist Tom Carter, summarised in a report published by the Ibis in 1912.

In the last 50 years the release from persecution by landowners, together with their adaptability, has allowed an expansion of range into the Western Australia wheatbelt which provides abundant food and water supplies.

They are often conspicuous in large flocks of up to 700 birds during summer which move around the areas spending days or week in any one location feeding and behaving raucously.

As with all parrots, Corellas are mostly seed eaters but can vary their diet depending on habitat and food availability.

Consumption of this corella by the Indigenous inhabitants of Southwest Australia is undocumented, but assumed from methods that could be employed, using a wounded bird near a pool of water as a decoy, and the reports of English colonists that it was a wholesome and good tasting meal.

[9] While generally uncommon, it has expanded its range in recent decades, and is therefore listed as of least concern by BirdLife International.

However, the nominate subspecies, Muir's corella, is relatively rare, with a population of around 3000 individuals, and is considered to be nationally Vulnerable.