I think the winner - the foxes - is extraordinary. As the photographer said on another site, the symmetry is amazing. The way the tails of both animals are curled, the heads, and even the expressions on the faces.
That, and the contrast between life and death and also the contrast between the colour of the two animals.
Granted, he had the best equipment available for the shot, but it must have taken an awful lot of hard work and patience and also some luck to be in the right place at the right time. The composition and also the exposure, with so much white in the scene, are perfect.
Quite inspirational. A worthy winner.