Need help- Roos or pullets

[abcw]

We are new to chickens and need some help- I have a few crowing but some others I can't figure out. Can some help me? All of these are about 12 weeks.
Here is my Wyandotte:

I also have two buffs. Here's the first, which I'm pretty sure is a roo:

Here is the other:

 

[abcw]

I also have some Jersey Giants:
#1

#2

Let me know what you think. Thanks in advance!!

 

[QueenMisha]

The Wyandotte is a pullet; the Buff Orps are cockerels. The black bird behind the Wyandotte also looks like a cockerel.

Edit: and the JGs in your second post are pullets.

 

[abcw]

The Wyandotte is a pullet; the Buff Orps are cockerels. The black bird behind the Wyandotte also looks like a cockerel.

Edit: and the JGs in your second post are pullets.

Thanks so much! I have about 4 JG Roos- two of them have started to crow so I am sure about them! But the smaller ones - the tail feathers were confusing me!!

 

[drumstick diva]

agree with Queen Misha