I believe I have a chick with this type of dwarfism in my flock. I thought this article was really helpful. Can you estimate how young of an age they usually pass? Mine is 19 weeks old and I have separated her from the flock as she has been badly bullied due to her having a chick peep and not sounding like a grown hen. Any tips on how to care for her? She seems to be doing fine other than some bully wounds. She definitely has all the features you’ve explain but still seems very healthy otherwise.