Is it a rooster?

[TheBigOne]

So, what's your opinion? Is my rhode island red a rooster? He/she is 15 weeks old. No crowing yet but the feather patterns make me suspect. Just wanted some ideas before I reluctantly have to take him back or find him a new home.

 

[Roxannemc]

Im not up on RIRs but it does look like its getting sickle tail feathers...conb is pretty bigI dont see a saddle or neck hackles not sure if all breed roos get them.I would guess it is a roo by its build tail and conb

 

[Peplers chicks]

Yap, a rooster that is, I made a mistake two month's ago, thought I bought two hen's, they turned out to be two roosters, they were very big, nearly no comb or sickle feathers. If I say big, I mean big, much bigger then a full adult barred rock, and the spur's on their feet were very small. It made me feel duh