Honestly didn't notice that until you pointed it out, haha!
When these snakes were emerging from brumation, they all huddled together, creating a giant pile of mating and warmth, which attracted the slower males. The late males then excreted hormones that made the other snakes believe they were females, so the already warmed up male snakes rushed over to the cold males and rubbed all over to get them warm as well. I'm sure there was more than just rubbing, but still. Pretty dang clever.
Just remembered watching this series called "Inside Nature's Giants"... which might not be up your alley, but they did dissect a big snake (can't remember what), a lion, and a whale over the course of the series.