Healthy looking hen is listless, not laying, not eating and shy of flock

[UpstateHenman]

Hello i have a small flock of five hens, 4 and 5 years old. My yellow buff orpington is not laying, but more importantly not eating and is listless and separating from flock. She is usually the most magnanimous bird I have. Been going on for maybe 2 days at most. She looks healthy- crop looks good. But i am worries about her. Attaching video of her. Thank you!

 

[HollowOfWisps]

Has she started molting? My usually energetic older flock is going through a very hard molt this year and for the first week they all stayed quietly inside the barn only moving around to get food/water. After that first week they perked back up and started being more active. The older they get the harder the molts are for them. My birds under 3 years old all had no problem with this years molt just the older ladies took it much harder.

 

[UpstateHenman]

She doesn't appear to be molting but two other birds are- so she may just be starting? She is my only yellow colored bird so looking for her feathers laying around. Thanks

 

[Eggcessive]

Watch to make sure that she is not being bullied or kept from food. Feel of her crop, then in the early morning see if it has emptied overnight. It should be mostly empty and flat then. To get an idea of what her droppings look like and if she is eating and drinking, placing her in a wired dog crate with her own food and water near the others could be good. I would take her aside and offer some soft cooked egg and mushy wet chicken feed. Look her over for any lice or mites on her body, examine her vent area and lower belly for enlargement, and note what her droppings are looking like. Are her urates white, is the poop runny or solid, and color. Pictures can be helpful.