Alder Tit – double diluted brown

Description:

This mutation is the combination of the brown factor with the double dilution mentioned previously. There is also co-dominance of factors. The same remarks apply as for the double-dilute and brown-dilute mutations regarding their genetic transmission. The presence of the brown factor combined with the double dilution results in a magnificent, highly spectacular phenotype in the bird. Some have mistakenly referred to this mutation as ‘isabelle’, whereas it has absolutely nothing to do with the isabelle mutation found in the siskin, which is sex-linked, as in the canary or the sizerin. A distinguishing feature is that the double-dilute brown has a streakless back, whereas the true isabelle has a streaked back.

Males:
The main characteristic of the plumage is a predominantly beige-brown colour (slightly browner on the head and back), with no streaking on the back and very slight streaking on the flanks in some individuals. The flight feathers and tail feathers are light grey with a beige-brown tinge and a bright yellow wing bar. The lipochrome on the beak stands out beautifully, giving the bird a yellow colour with light brown highlights. This mutation is a real feast for the eyes but has the disadvantage of being much more fragile than the others, due to the combination of recessive factors.

Female:
Same characteristics (except for the crown, which is lighter) but with a very slightly browner back and a less intense, less bright yellow.