Thanks this is Baldy who we have watched him and his partner breed in four different nests over the last 6 years. Unfortunately his partner appears to have beak and feather disease, which she may die from and pass onto Baldy and their future young. She most likely caught it through accidental indigestion of faeces from an infected bird, both attracted to a house providing artificial seed feeding. Such feeding is not good for Gang-gangs - it is killing them.