The fallow mutation is probably among those which still need investigation and bring some controversy.

Terry Martin gives a strong definition in his book ‘Colour mutations & genetics in parrots’ 2002 edition:

“To be a fallow mutation, a gene must produce red eyes in the adult bird, be recessive in inheritance and change all black pigment (or grey colours) to light brown shades without altering and change any other pigments or distribution. Because black and grey are reduced to light brown, the bird loses any deep colours of green or blue, becoming more yellow or white in appearance and lighter in colour overall”.

In the same book it is stated that international communication between breeders enabled to know that there are four different fallow colours, more or less diluted from light grey to light brown including grey-brown and brown. Each one being named differently (from darker to lighter: ashen fallow, dun fallow, bronze fallow and pale fallow).

It is important to underline that they are not multiple alleles for the same locus but are on different loci and mating them together will produce only normal birds split to the parents’ mutations.

To follow Terry’s book I had previously used in an article and on this website, the name ‘bronze fallow” for the Bourke that we usually call “Jaune” in French (yellow in English). Following recent discussions I had to revise my statement to fit a general choice.

It seems that the “bronze fallow” should still have a visible iris, when the “pale fallow” should have a completely transparent iris (which is the case of the “yellow” Bourke). Although the colour of the yellow Bourke should be a bit lighter to fit better the “pale fallow” definition and the iris visibility isn’t only due to pigment concentration, I think it is good to adopt the name “pale fallow” for the ex “yellow” Bourke, as it has already been adopted by others. Also because “pale” is easy to understand compared with the darker “fallow” Bourke.

But for the previously called “Fallow” Bourke in French I would just keep for now the name “Fallow” until we have more information about it.

From some information that I have gathered I suspect that, besides the "pale Fallow" (pale brown ) , could exist (or have existed) two different “dark fallow” Bourkes: the common one being a brown (“bronze fallow”) and another one, being much darker and more a grey-brown colour (dun fallow?)…so maybe is there a third fallow mutation in Bourkes?

I am looking for breeders breeding Bourkes of that type, although the Fallow Bourkes are not extensivley bred, and would appreciate your help if you have those darker fallow Bourkes in your aviary and could bring me any information…  

 Alain Campagne

Bibliography Terry Martin: Colour mutations & genetics in parrots, Genetics Psittacine list, Mutavi website and information.

male n°1: orange tinge on neck and back and in the pink areas

male n°2: some more melanin giving a greyer tinge, yellow and pink are a bit different

pale fallow

female, sister of male n°1, also showing some orange tinge on neck and back.

fallow

  fallow male

fallow female

 photos Alain Campagne & Daniel Moyer