Super red skin on chicken's butt

[MaeM]

Hi, some rescuers gave me this rooster a week ago.

Today I noticed his butt is super red, as you can see in the picture. I saw some redness in his belly, too.

I immediately thought about external parasites but I don't see them in his body and I don't think I have red mites in the coop because it's been empty for 20 years...would they still be living there with no birds to feed on?

I wonder if this could be from a past infestation in his previous "home", where he was being neglected and kept in a small cage.

Any ideas? The chicken looks and acts normal/healthy apart from this.

 

[MamaPoult]

Hi! I bought an Australorp rooster when I first got into chickens. He was super healthy and great otherwise. However, after I combined him with my existing flock I started noticing his back side looking increasingly red as you've described. It took me a while to figure out why but eventually I realized that my hens would pluck his butt feathers everytime he'd bend down. It took a few weeks but after he became fully integrated and respected the redness went down and he grew his feathers back. Definitely wait for others to pipe in but hopefully it was just a case of bullying at his previous living situation and it will grow back. Best of luck.