The courtship ritual. The cock bird puffs himself up, hunches his back and then lurches around the hen bird making heavy breathing noises - much like humans I guess.
A follow on from the pic in the main album at http://365project.org/terryliv/365/2014-08-28.
I was surprised that no-one asked my why my first pic was titled This . . . .
Great shot, very David Attinbourgh. (I think that's how you spell it).