identity

Information about the wildtype Bourke

Names

Scientific name:

Neopsephotus Bourkii. Neo (Greek) = new, psephotus (Greek) = “inlaid with pebbles”. This is a nice reference to the pattern on the wings, be composed of the brown wing coverts, margined with white.

Local names:

Bourke’s parrot or Bourke’s parakeet. The Bourke’s parakeet is discovered by sir Thomas Mitchell in 1835. The Bourke is named after the governor of New South Wales, in that time, sir Richard Bourke. This is the reason that the name Bourke is always written with a capital.

Pink bellied parakeet. The Bourke has a rose belly and a dark brown-rose breast. This colour corresponds to the red coloured soil in his habitat.

Bourke’s grass parakeet. The Bourke is one of the little parakeets, the grass parakeets. They live in open spaces. Mostly they are foraging on the ground, eating seeds of native grasses, like the spinifex.

Night parrot, Sundown parrot. The Bourke is active in the early morning and late evening when it is growing dark.

Local names of the wild type Bourke are typifying the colour, like pink bellied or the behaviour, like diet and activity. There is a difference between the local names, people gave to the birds in there neighbourhood, and the scientific name, given by biologists. The scientific name is a double name. The Bourke is neither member of the Neophema group (Spendid, Turquosine, Elegant etc.) nor to the Psephotus group (Hooded, Red vented Blue Bonnet, etc). They named him: Neopsephotus. It is an "individual", like the Cockatiel and the Swift parrot. ("Parrots of Australia", by Eastman and Hunt (1966).

group of Bourke's

Colour

The main characteristic of the plumage of the Bourke is the brown colour, supplemented by dark rose and some pale blue. The main colour of the Bourke is brown, earth brown. He is the only brown parrot in Australia.

The melanin pigment gives the warm brown colour.

Melanin pigment has several functions. The Bourke lives in a dry and warm climate. The feathers have a lot of melanin pigment. The upside of the feathers of the Bourke is darker than the down side. The dark back is catching more sunlight. Melanin stops the harmful ultraviolet light of the sun.

Another function of the colour and colour pattern of the Bourke is concealing, preventing detection, hiding the bird in his natural habitat and protecting him against enemies. The chest has brown undulating markings on a rose brown underground. The wings have brown coverts, margined with yellowish white. The belly is rose. The rose colour of the belly corresponds to the red soil of the open sandy country. These brown and rose colours and peculiar colour patterns give shape to a perfect camouflage when the Bourke is seeking for food on the ground. This camouflage structure gives protection in the open regions.


In the evolutionary development of colours in birds there are two directions: cryptic colours, promoting concealment and advertising colours, attracting attention, promoting recognition. Parrots living in the tree tops are most much more colourful with advertising colours then parrots living and feeding on the ground. The Bourke has such a concealing colouring, he is spending most of the time on the ground. It is known that birds who have a camouflage colour and -structure are always alighted on soil matching their plumage in colour and pattern.

An "Individual"

For a long time fanciers who were breeding mutations were treating the Bourke as a member of the Neophema group. Some people do this also today. But the differences between Bourke and Neophema are big. We learn a lot of the specific colour elements of the Bourke's as we compare them with the splendid and the turquoisine, members of the Neophema group, and study the differences.

1. Colour of the plumage: Neophema are green birds, green in several varieties, olive green in the blue wing parrot, golden olive in the elegant, brownish olive in the rock parrot, bright grass green in the orange bellied parrot, bright green in the splendid and the turquoisine. This means that the green colour is a main characteristic of the Neophema. They have feathers with bluestructure and yellow pigment in the whole plumage. The combination of this two colouring elements gives the green colour. The Bourke is an earth brown bird. He has, in some restricted feather fields, feathers with a blue structure, but most of the plumage consist of feathers without this blue structure. He has a little bit of yellow pigment but we never find this pigment in the feathers with a blue structure. The wildtype Bourke has no single green feather. The Bourke is not green. He should not be treated as a green bird.

2. Eumelanin: Neophema have black eumelanin. This makes there colours bright. The turquoise coloured head of the turquoisine, the cobalt blue head of the splendid are some examples. The Bourke has brown eumelanin. All the colours of the Bourke, the wild type and the colour varieties are softened by this kind of eumelanin. The blue colour is pale and the red colour is rose. The splendid male has a striking red chest. The turquoisine male has a bright red wing patch. The Bourke has a rose brown chest. Rose colour is an exception in birds. Rose is a mix of brown and yellow pigment. This rose colour is part of the camouflage of the Bourke. The soil and the sandstone riffs where he is foraging are red coloured. We see the differences in the wildtype. But also the colour varieties are interesting to discover the different influence that brown and black eumelanin have on the plumage.

3. Colour structure: The wing coverts are forming a structure on the wing. In the wildtype the brown wing coverts are margined by white. This "roofing tile structure" is very typical for the Bourke. Neophema are missing such a structure.

4. Colour function: The red coloured chest of the male splendid and the red wing patch of the turquoisine has a function in the courtship display and is a sex symbol. The red pigment of the Bourke has another function. Male and female have a rose coloured belly. This is an adaptation to the red soil where they are foraging and is part of their camouflage, but it plays no role in mating. The Bourke's cock has a blue fore head and pale blue under wing coverts that he is showing in courtship display.

pictures of differences of splendid and Bourke

5. Research: The Bourke is a separate genus. He was for quite a long time considered as a member of the Neophema group. The study: “Biochemical Systematic of Parrots” by the SCIRO, the Australian National University and the Museum of Victoria, is a recent research report about the relationship between parrot species. One of the conclusions of this study was that there is no close relationship with the Neophema. This corresponds with the fact that there are no hybrids of Bourke and Neophema. This corresponds with the fact that the colour of the wild type is very different from the colour of the turquoisine, the splendid and other Neophema. And it fits in with the experience of breeders, that the Bourke has different possibilities than the Neophema regarding the breeding of colour varieties.

Conclusions

Compared with the Neophema the Bourke's parakeet has a very different colouring and colour distribution. When the colouring qualities of the wild types of the Bourke and the Neophema are different we can expect differences in the colour varieties.
Thorough knowledge of the colouring elements of the wild type species should be the starting point of breeding colour varieties and naming the new mutations. False conclusions and false expectations about breeding and developing of colour varieties are possible when the genetic differences of the wild type Bourke and the Neophema and other green species are neglected.

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Copyright 2003 © Bob Fregeres

E-mail: fregeres@bourkes-parakeet.nl

28/11/03