PeeWee the rescue Cockatiel came to us about 30 yrs ago w/chest bald & some belly & body feathers gone. His senior owner passed & the granddaughter took possession of PeeWee in his cage & kept him in her enclosed laundry room w/no windows, lights off, plus she kept a cover over the cage 24/7 & lifted it only a few seconds to sprinkle seed into his feeder & add water to his waterer. How the poor little guy survived for weeks in the dark is remarkable.
My DD saw his pathetic existence & pleaded w/me to adopt him (cuz we raised Cockatiels before) if she could convince the granddaughter to give him up. The granddaughter was happy to get PeeWee out of her laundry room so he came to us in a bald mess. His senior owners never kept him caged & he was accustomed to a lot of interaction w/his senior owners. PeeWee went on car rides w/them, motorhome camping sitting on the back of front seats, went into showers w/humans, & he spoke some words.
Once we got PeeWee we let him come out of his cage & he was so happy chirping & exploring but he was still picking his feathers. We made a cone for him & kept it on him till he grew out new feathers ~ several weeks he wore that cone like a champ. He learned to share our bigger cage w/our 2 English Budgerigars & they would grab his cone & drag him around but he would break loose from them when he wanted. After we removed the cone w/ his new feathers all grown in he never picked again. We expanded his & the budgies diet to fresh fruit & veggies. We took him on car rides ~ he would wolf whistle at pedestrians in the crosswalks, not anything we taught him so must've been learned from his previous owners.
We taught him the Andy Griffith Show whistle tune, & he loved the Sit N Sleep Mattress commercials! We were his 4th owners but we think we did right w/him. His senior owners were smokers so he came to us wheezing. After a clean air home w/us he gradually lost the wheezing. The vet said he was small for a Cockatiel but otherwise healthy. He lived to 23-1/2 before his little heart stopped. We never got a picture of our PeeWee w/his dog cone.
New type of bird cones on Amazon
Here's a parrot cone on Amazon but bird cones were not a thing we could find 30 yrs ago & I made one out of milk gallon plastic shaped like this parrot cone which should work for chickens just as well if it's an adjustable closure!