Is a black chick with a white dot on it's head always a sexlinked male?

[VinnyVincent]

Hello,
I just tried my hand at hatching eggs for the first time. Since it was my first time, I just got some cheap barnyard mix eggs. The person I purchased them from said they had a "big red barnyard mix rooster" and barred rock hens, amongst a few other breeds.

A lot of the chicks came out either solid black, or black with a white spot on their heads. Would it be safe to say that the ones with the white dots on their heads are males?

I'm wondering if any red colored rooster mixed with a barred rock can create a sexlink, or if it has to be a pure bred RIR or NHR rooster to create a black colored sexlink?

 

[casportpony]

@Pyxis, @nchls school, @ColtHandorf, @Brahma Chicken5000, can you help?

 

[Brahma Chicken5000]

The genetics have to be just right for sex linkage to work. @nicalandia is more knowledgable in this regard.

 

[Willawong Hill]

I think any plain/ non barred rooster with a barred hen will make a sex link where all the boys are barred and all the girls are plain.

 

[Pyxis]

I'm wondering if any red colored rooster mixed with a barred rock can create a sexlink, or if it has to be a pure bred RIR or NHR rooster to create a black colored sexlink?

Yes. As long as he's not white or barred, any rooster over a barred hen makes a sex link. If they only had this one rooster, or at least no barred roosters, any barred offspring must be males.