I had it with a Light Sussex that I got from Sandhill -- I had to go there as I had no cock birds. One of them had a sprig tail, Clive, and i used him with my girls. It seems to be a sex-linked recessive or at worst incompletely dominant, as none of the hens got the trait and just one male, so I've been working on culling males that are born with it and so far so good.