Chick doesn't look like other roosters or hens all by same parents

[alxw]

The chick in the back with black edging on the tail is a roo BUT the chick in the front its tail curls? The roo chick in the back hatched a week earlier than the one in the front but they are both from the same parents. The other hens in the clutch their tails do not curl like the odd ball in the front. Is this a sign that it will be a rooster but with a better tail its comb is not as developed as the one in back but like I said the mystery chick is a week behind the roo. I'm trading two poulets for some Deleware chicks and just want to be sure I'm giving them poulets so I asked for a week to be sure that I knew which chicks were girls and which were roo's. They are 4 1/2 months old.

 

[hdowden]

looks like a cockerel

 

[ramirezframing]

I have had pullets do that as chicks can you get a body shot of it standing and of its comb

 

[alxw]

I will take better pics tomorrow, even though he is a week behind the others would his comb be significantly not as developed as his other siblings who are a week older? The 2 roosters who are a week older than my mystery odd ball chick with curled tail are already starting to mock fight and chase each other. Is a week really that big of a jump in development? Can I just assume that at 4 1/2 months there are obvious signs on which chicks are what, but this curly tail is throwing me off since not one of the other five chicks exhibited a curly tail. Should I treat my odd ball curly tail as the redhead in a family of brunettes lol and just see it as a genetic curve ball instead of a gender indicator?