Why is the Hen Crowing?

We bought chicks in the spring of 2010. We bought 14 chicks. They were all hens. Though we had a rooster for awhile, Napoleon, the bantam Mille fleur who ruled the roost with an iron claw met his Waterloo years ago.

The six hens who are still with us, 7 years later, are still laying about 6 eggs per week. It's unusual to get any eggs from them at this age, but we never forced them to lay through the winter. Hens have a finite number of eggs and forcing them to lay all year will shorten the number of years they will lay.

A month of so ago, we noticed one of the hens seemed to have gotten bigger. Was this just our imagination? It had always been a large bird. Then one day, we heard a strange noise coming from the back yard. It sounded like... crowing? Okay, it sounded more like an attempt to crow, but definitely not a sound our hens have ever made.

So we kept watch on the big one. Gradually it developed a larger comb and a really large wattle. The wattle is the red bit that hangs right below their beak. The comb and wattle are also bright red. It was strutting, yes, strutting across the yard. No self respecting hen would ever strut. Now it's starting to grow those lovely tail feathers in a darker color with a distinct pattern on them. Not much to see yet, but the potential is there.

Here you can easily see the difference between our hen and our new rooster. I've started using "he" instead of "she".

It's nice to have a rooster in the flock. They will stand guard while the hens eat and they are more alert and watchful for predators. Napoleon had a specific crow for times when he wanted the hens to get in the hen house immediately, with no arguments. We'll see what this rooster will do.

There is an explanation for all this. Nature has provided hens with two gonads, only one of which develops into an ovary. The other remains an ovotestis... in other words, a gonad with the potential to be either an ovary or testis, but won't develop unless the working ovary becomes damaged. The estrogen level will go down when the ovary stops working and then the testosterone level goes up, and the hen starts to look and act like a rooster. It's called Spontaneous Sex Reversal and is explained well in the link I just gave you. 

I wonder if this is more common with older birds? If so, might we see more of our old ones transition to a different gender? I wonder what would happen if all six did this? They've lived together too long to start cock fighting now, so I suppose they'd just roost around in the evening, drinking beer and smoking cigars...

...and practicing their crowing.