Blackbird with a growth

[goosey]

I saw this blackbird today foraging around in dead leaves. It had a very large growth on the side of his head which stuck out quite phenomenally. Sorry about the quality of the second image but it does show the size better.
It doesn't seem to cause it too much problem, perhaps because it is towards the back of the head so doesn't obstruct vision and it has survived to adulthood.

[lemars]

It makes you wonder if birds can have undeveloped bits of twins attached to them, doesn't it ? It would be interesting to know what it is - and a better affliction to suffer than some photos I've seen recently of blackbirds becoming bald.
Yours seems quite content with its extras.

C