Today, I noticed a pair of blue tits attacking and cannibalising a third blue tit that had got itself trapped in a crack in the bark of a sweet chestnut tree - the crack itself leads into a larger cavity. By the time I noticed what was going on, the trapped bird was dead and had a substantial amount of flesh removed from its head.
I'm no expert on these birds, and was wondering if this behaviour was either:
A) The pair trying to 'evict' the trapped bird and take over the nest for themselves?
B) The pair was trying to kill the third bird in order to reduce competition?
C) The pair found the trapped bird and decided to treat it as a source of food?
Or all of the above. I certainly have never seen or heard of this manner of behaviour before.
Sorry for the poor quality of the picture - it was a still taken from a video.
