Blue Tit

Blue Tit

Observation - Blue Tit - UK and Ireland. Description: This Blue Tit appears to have an abnormal growth of feathers on its back. I thought at first it was moulting, but it appeared in the same state for several days (and has not been seen since). Has anyone any explanation - eg ? tumour

This Blue Tit appears to have an abnormal growth of feathers on its back. I thought at first it was moulting, but it appeared in the same state for several days (and has not been seen since). Has anyone any explanation - eg ? tumour