Clearwing budgerigar mutation

[1] The wings and mask carry pale grey shadows of the normal markings and spots.

These brighter coloured 'Greywings' were very popular in Australia and were preferred to the more subdued shades of the true Greywing.

[3] In the mid-1930s there was considerable debate about the nature of these brighter Australian 'Greywings', some maintaining that they were a distinct mutation and others insisting that they were obtained by selective breeding from normal Greywings and/or Dilutes.

[4] The latter name originated from a pair of 'Greywing' Cobalts (of the type with intense body colour) which were presented to HM King George V in, it is believed, 1935.

[5] These birds came from a strain which had been cultivated by Harold E Pier of Peakhurst, New South Wales, over the previous seven years.

The correct identification and classification of the two quite distinct Greywing and Clearwing mutations was clearly understood by some Australian breeders by 1936, and probably considerably earlier, but the first article[6] to appear in Britain which clearly set out the genetic behaviour of the two mutations was written by R B Browne of Hornsby, New South Wales and published in the Budgerigar Bulletin in June 1937.

So the Clearwing mutation exerts a selective effect, not on the wing feathers per se, but on cortical pigmentation.

Both alleles are partially expressed, giving the bird wings like a Greywing and a body colour like a Clearwing.