Ouch! Gerrof Me!

Over at Ham Wall there seem to be at least 3 pairs of Great Crested Grebe sharing the same lake.  They are fiercely territorial, particularly in the breeding season and when two pairs met and neither would back down carnage resulted.  Both male and female grebes took on their competitors in what looked to be full on combat.  Fortunately none of the participants seemed to be permanently injured or disabled once peace was restored, although I've heard of birds getting drowned in this sort of situation.

Thereafter the birds seemed content to issue threats and make threatening gestures when other couples got too close, and there was no more actual fighting.

You probably need to see this in large to realise that the grebe closest to the camera is ripping feathers from the chest of the one furthest away.