Silkie Roo Showing His Masculinity Already?

[hokankai]

I received two silkie chicks from a breeder here in town. One of them is already acting VERY roo-ish at 4 weeks old. It has a smaller "bump" on its head than the other, carries itself fairly upright and likes to stand up tall to get a good look at things, is a lot bigger than the other, and its peeps are somewhat loud and scratchy. Is it possible I have a roo who decided to make my life easy and show me his stuff early?

Here's a pic of the chick at 2 weeks

compared to its partial sibling

 

[TeriyakiChicken]

THEY'RE SOOOOO CUTE!
Sorry I'm not much help

 

[AccentOnHakes]

The "bump" is just a vaulted skull, nothing to do with gender.

 

[hokankai]

I know that, but the breeder (Marjorie Best whose been breeding award winning silkies for a looong time) told me that her female silkies will have the knot on top of their skull and that males will not, which is why I mentioned it.