Battle of the Sexes

Who would be a female frog? Two males have this female in amplexus (mating) mode in my garden pond. They've been at it for over an hour. The bigger, darker male has dragged them all down into the depths on more than one occasion which could kill the female.

I'd only been saying to Len at breakfast that February was the month when we should begin to see frog spawn. 

Maltreated like this, perhaps it's not surprising that I've come across the bodies of dead females floating in the water in the past. Perhaps the carcasses are intended to provide nutrients.

I'll go out a bit later to try and determine what might have happened eventually. The smaller male on the female's back was being quite vocal blowing out his vocal sac at the start. I think they were all getting tired.