Returning Blackcap?

Further to Owain Gabb's observation of a returning Blackcap, in this earlier post http://goweros.blogspot.com/2010/02/returning-blackcap.html , a distinctive female Blackcap is once again present in our garden. As you can see she has feathers missing around the eye, in fact around both eyes. We had an identical bird about 4 winters ago which returned the next winter. It would make this bird quite old, if it is the same bird? I haven't noticed this condition on many birds and is the only one I remember on a Blackcap. Given Owain's observation the possibility remains that it is a returning bird. The food selection in the garden is much improved these days compared to previous years, but this bird's ability to control the feeders is also very similar.