missing feathers

[deeschicks19]

One of my girls (Plymouth) is missing a circle of feathers below her neck. I looked for mites but saw none. She is acting just fine and none of the others seem to be bothering or picking on her. All my girls were a year old April 30th. Any ideas or clues or guesses? Is that the beginning of molting? I live outside of New Orleans so it has been extremely hot here. But there run is very large and very shaded and in their coop they have a ceiling fan and I have been using an oscelating fan also the last couple of weeks too. (sorry for the spelling)
Help.
Thanks

 

[Chicks Galore3]

There could be multiple reasons - here are the ones I can think of.

There is, of course, picking, but you said you already investigated. Chickens generally molt first around 18 months of age. But this isn't saying she isn't. Chickens don't always follow the rules. She also could be molting from heat stress. (but it sounds like you keep it well ventilated/cool.) Is she brooding? Very determined hens will pluck out their chest feathers to create a "brooding" patch to keep the eggs warm.

 

[deeschicks19]

No she isn't brooding. And she is acting just fine. I just went in and cleaned out their nests and put new down along with DE in them. She actually just got in one of the nests to lay. I am not going to worry about it unless she starts acting funny. And the spot doesn't look any worse at all. Thanks.
These are my first girls so I am very new with this and I love my girls so of course I worry if I see anything wrong.
Thank you