The re-creating of the blue grizzles in
In pigeon genetics, it is great if not only
questions arise, but also once given answers. For example, in a
contribution by Frank Zetzsche to the grizzles in the case of
Thuringian Selfs in No. 18/2019 of the German ‘Geflügel-Zeitung’.
Thuringians are recognised in the standard both in short muffed as
well as clean-legged in three sex-dimorph color-classes for cocks
and four for hens. There are also in addition blue grizzles with
bars in both sexes. The inheritance in the sex-dimorph colors is
based on the fact that cocks have twice the gene Frosty, the females
by gender only once. The coloration of frosty homozygous cocks is
bleached. No, or at least for the author of these lines, no clear
bleaching is recognizable in the females and heterozygous cocks.
Grizzles are rarely shown, clean-legged have for long disappeared.
Fig. 1: Thuringian Self cock blue ground colored;
Fig. 2: Thuringian Self hen blue bar
Fig. 3: Thuringian Self young cock, homozygous
frosty and heterozygous grizzle; Fig. 4: Thuringian Self young hen
with frosty, heterozygous grizzle (photos: Frank Zetzsche)
In the process of re-creating Frank Zetzsche
confirmed the assumption that homozygous frosty blue grizzle cocks
with visible bars, as are required in the standard, are not
possible. However, hemizygous grizzle females who only have the
factor one times, can be raised. Therefore, blue grizzle cocks that
fit the today standard requirements with distinct bars are the only
ones in the color palette that do not have Frosty or have to be
heterozygous only. If one interprets the word ‘Self' in the name of
the breed in such a way that one gets only recognized colors from
the mating of any recognized colors, everything is ‘one color', then
they do not fit into the breed. Because you will raise not
recognised colors from them. Years ago, some fanciers wanted to
delete the grizzles already from the standard.
Fig. 5. Thuringian Self cock (not homozygous
frosty); Fig. 6: Thuringian Self muffed blue ground colored cock
with a blue bar hen and light ground colored cock with a silver hen
(below). Sources: Sell, Genetik der Taubenfärbungen, Achim
2015 and Sell, Pigeon Genetics. Applied Genetics
in the Domestic Pigeon, Achim 2012.
If one draws the parallel to the recognised
sex-dimorph color classes, then there is another possibility. In
blue-bars the bars are bleached in homozygous frosty cocks, and the
overall color becomes lighter. Hens are blue bar. It's not different
when it comes to blue-grizzles. The bars are not or hardly
recognizable at the cocks and the already bright color is further
brightened. Hens are grizzle bars. The light ground colored cocks
have their counterpart in the silver females, the yellow ground
colored cocks in the larked females.
Fig. 7: Thuringian Self cock (at the left),
homozygous frosty cock, heterozygous grizzle, and a blue grrizzle
hen (hemizygous frosty). Source: GeflügelZeitung 18/2019.
For a discussion of the inheritance see 'Pigeon
Genetics' and the German language book ‘Genetics of Pigeon
Colorations’ (Genetik der Taubenfärbungen), the second source also
with many details on the history of the breed.
Zetzsche, Frank, Erzüchtung der glattfüßigen und glattköpfigen
Schimmel bei Thüringer Einfarbigen, GeflügelZeitung 18/2019, S.
Sell, Axel, Genetik der Taubenfärbungen, Achim 2015.
Sell, Axel, Pigeon Genetics. Applied Genetics in
the Domestic Pigeon, Achim 2012.