An estimated 50 percent of pet birds engage in “over-preening”, but certain species of parrots are significantly more prone to this problem. Those at particular risk are birds that travel in large flocks when they live in the wild. These birds get lonely without a lot of social interaction. Without another bird, or at least a person, to keep them company, they behave like a lost wild animal. They get anxious, develop behavioral problems, and yes, pull out their feathers and even pick at scabs. More nomadic bird species like Amazon parrots or macaws are at less risk of this.
19 Totally Mind-Blowing Facts