These are "barred rocks"

[MrFluffyandGirls]

Looks like the production ones I got one time. They were good layers.The well bred heritage ones are not as readily available, you have to go looking for those.

 

[house1917]

I'd almost consider some of their patterns to be cuckoo- and found this explanation between barred and cuckoo patterns (not my work- citing @Chris09 who's not an active member)

This is a Sex-link gene that stops and starts pigment production as in feather growth to give the well-known barring pattern as seen on Barred Wyandottes and Scots Greys. The extremely narrow and sharp barring seen on the Barred Plymouth Rocks is achieved by the presence of the gene ('K') for very slow feathering growth,which allows for a lot of on/off sequences in the time it takes for a feather to grow. The same barring gene ('B') when on a rapid feathering breed gives wide, coarse, fuzzy "Cuckoo Barring" as seen on Cuckoo Marans, Cuckoo Pekins (Cochins) and others. The barring gene also interacts with the gene on the E locus, all of the above examples being based on the E plus melantoics. Thus all these barring and cuckoo breeds would be self-black if they did not have the barring gene. This gene has greater pigment-restricting effect on black pigment than it does on red or gold pigment. When the barring gene is applied to the Wild Type pattern, the Crele variety is produced; and the barring on Columbian pattern combination is seen on Rhodebars, one of the autosexing breeds.

 

[Lovem all]

Thank you so much for the information!