BR chick head spots

[jossanne]

I got 14 BR packing peanuts this morning, and I'm thrilled about it. I know packing peanuts are supposed to be males, but it would be okay with me if they made a mistake or two...

So I have a question about head spots.

How accurate is it judging gender by size and shape of their head spots? Some of them have huge spots (like stripes across their heads), some have almost none.

Is it greater than 50/50 chances that head spots tell you the gender?

 

[speckledhen]

It's fairly accurate, but isn't the only sexing tool to use. You must take a couple of traits in combination, the down color and the headspot. Read the doc below and it will explain it.

Historical Document
Kansas Agricultural Experiment Station

SEX IDENTIFICATION IN PUREBREDS
BARRED PLYMOUTH ROCKS

It had long been recognized that the size of the light head
spots in Barred Plymouth Rocks varied in the two sexes. The
males tend to have larger headspots and the females to have
darker colored legs. However, this method has not been sufficiently
accurate to be of much commercial value.
Quinn and Knox (1939) attempted to separate the sexes of
Barred Plymouth Rocks by means of the intensity of the black
pigment in the down and legs. In different lots of chicks they
report 83.5, 86.1 and 91.8 percent accuracy.
Jerome (1939) describes a method of sex identification in
Barred Plymouth Rocks based upon the regularity of the outline
of the head spot rather than the size of the spot. Those chicks
having headspots irregular in outline and scattered in appearance
are males while the females tend to have headspots with
more regular outlines. The author claimed an accuracy of 90
percent or better when considering only the headspot and 95
percent if the color of the legs was included in the consideration.
The Canadian Department of Agriculture (Anonymous 1941)
issues an excellently illustrated bulletin describing the method.
It is stated in the bulletin that the method “is widely practiced
in Barred Rock chicks by commercial chick sexers.” Sex identification
is based upon outline of head spot, color of legs and
shade of down color. There are several types of male and female
head spots some of which are shown in Figure 1.​

 

[jossanne]

Excellent information, thank you! Examining down, legs and spots now...

Here's a picture you can kind of see the differences in the babies' spots. There are ten cochin bantams in the box with them.

*edited to add pic*

 

[mikarod]

Wouldn't it be funny if they gave you all male sex-links...LOL

Male (black) sex-links all have the white spot on their heads.

 

[jossanne]

LOL I didn't even think about that! Hmmmmm after all this wondering and thinking and trying to judge their cute little legs, heads and fluffs.....