Americaunas first pic. Hooty and Eddie. Easter Egger 2nd pic.
I have several Easter Eggers I just hatched from my flock, so I'll add more pics when they grow up
Americaunas are purebred, Easter Eggers are hybrids. So for those that keep posting they're the same, that is incorrect.
Ameraucana is the true breed. 'Americauna' is one of many misspellings that hatcheries and backyard breeders use when talking about their Easter-eggers, usually because they don't know any better.
For the record, none of the birds in your post are true Ameraucanas.
I got three SLWs from Tractor Supply, one had a rose comb and two had single combs- which confused me.
So, there are a couple factors to that. The main one is that the rose comb gene is completely dominant over single combs. What that means is that a bird with a rose comb may have two copies of the gene and be pure for it, or they may only have one copy of the gene and have one gene for not having a rose comb in the second slot for that trait. Despite that one is pure for the gene and one not, these birds would be indistinguishable because of the dominance of the trait. If you take two birds carrying only one copy of the rose comb gene and breed them together, about 1 in 4 of their chicks would have a single comb.
On top of this, there may be a connection between the rose comb gene and fertility in roosters; males with two copies of the rose comb gene can be less fertile than males with only one copy, or males with no copies of the gene. Hatcheries like where
TSC gets their chicks keep their birds in large breeding pens, where several males are covering many more females. In this way, they assure fertility and are able to produce many chicks. However, if a pen has both males that have two rose comb genes and males that only have one rose comb gene, then because of the fertility issue connected with the double dose of the gene, the ones with only one rose comb gene are most likely fathering more chicks and those chicks have a 50-50 chance of not inheriting a rose comb gene from their father. Because some of the females can be the same way, having only one copy of the gene but still being indistinguishable from the hens with two rose comb genes, some of the chicks produced from these pens end up with a single comb instead of a rose comb.
However, all that being said, even breeder lines of Wyandottes have single combs pop up every now and then because of the aforementioned fertility issues associated with the rose comb gene.
