Non-crowing cock

[Suechooks]

I remember reading in some chicken book, a good many years ago, that hens only lay eggs from one ovary, and if it packs up, the other one MAY start to operate as a testicle. It was an old book and this might be one of those things that has since been proven wrong, but it did seem to be based on actual scientific investigation.

I've read that too!

[mandyballantyne]

I remember reading in some chicken book, a good many years ago, that hens only lay eggs from one ovary, and if it packs up, the other one MAY start to operate as a testicle. It was an old book and this might be one of those things that has since been proven wrong, but it did seem to be based on actual scientific investigation.

Interesting, one of my girls who I don't think is laying has started to mount the other girls?

No one has gone broody so I hope she/he is only playing the part of a cockeral..........

Mandy

[RichmondHens]

This cock is fully male (as far as I'm aware) and I have bred from him so he is/was fertile. I'm not sure why he has stopped crowing but am sure it is a psychological thing rather than physical. He has two male youngsters in with him who are not fully mature yet (they are about 5 months). He has started driving them away from the females if they show interest but is not doing the crowing "this is MY territory and these are MY girls" bit. This is my bantam horde comprising some 20+ birds, which I operate on a different system to the LF which are all rather more "managed" in smaller breeding groups.

I am curious about him but feel sure someday in the future he will resume crowing.

[RichmondHens]

Interesting, one of my girls who I don't think is laying has started to mount the other girls?

No one has gone broody so I hope she/he is only playing the part of a cockeral..........

Mandy

If there is no cock to lead the flock the dominant hen may take on the characteristics of a cock which can include crowing and attempted mating.

And hens will go broody regardless of whether there is a cock in sight. Some breeds are more prone to it than others.

[nellie-m]

I remember reading in some chicken book, a good many years ago, that hens only lay eggs from one ovary, and if it packs up, the other one MAY start to operate as a testicle. It was an old book and this might be one of those things that has since been proven wrong...

Here's what the University of Florida says:

Typically, female chickens only have one functional ovary, the left one.

The right ovary and oviduct are present in the embryonic stages of all birds, but typically do not develop in chickens.

In general, spontaneous sex reversal has been described as the result of pathological conditions (e.g., ovarian cyst or tumor, diseased adrenal glands) which cause the left ovary to regress.

Residual tissue in the right ovary proliferates in the absence of a functional left ovary. This regenerated right gonad is known as an ovotestis and may contain tissue characterisitics of the ovary, the testes, or both.
There are reports of these ovotestes producing semen capable of fathering offspring. Most, however, will never lay an egg or sire offspring.

The "ovotestes" are steroidogenically functional and secret androgens, as well as estrogen.
As a result, the bird develops male secondary characteristics. So while the bird is genotypcially female, it will be phenotypically male.

Footnotes
1. This document is FACTSHEET PS-53, one of a series of the Department of Animal Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: November 2000.

I might add that not only diseases can cause the left ovary to stop working, but also old age - although of course most hens don't get the chance to die of old age... I told you I have two hens right now that hatched in 2000. One of them has started to develop sickles and neck hackles, not as pronounced as in roosters, but there's definitely a change in her plumage. She has not (yet) started to crow, though, she behaves like a normal hen. The other still looks like she always did. Both stopped laying years ago. I have a picture of them somewhere, must go and see if I can find it...

Sometimes hens show a change in behaviour when they lose their male companion - they start to crow or start to mount other hens, like Mandy says. Unless you can actually see secondary sexual characteristics of males appear (saddle and neck hackles, sickles, large wattles and comb etc) this does not necessarily mean their ovary doesn't work anymore. I've seen these behaviours stop as soon as I gave them a new rooster (although such hen may at first be NOT AMUSED and try to fight him!) and these hens also continued to produce eggs.