[Cazador]

I'm not surprised that a theory suggesting they could leave the den earlier and mate earlier would be shot down. Any organism that's unable to synchronize mating activity (in terms of location and timing) in a genus with such a limited reproductive period (particularly as one travels further north) is doomed to have impaired, not enhanced, reproduction. Moreover, black snakes in a winter's den wouldn't get the benefits of absorbing more solar energy, so again, it seems like a flawed theory.

Compared to wild-type individuals, melanistics are more likely to enjoy the benefits of faster digestive rates, higher metabolic rate, better immunity, enhanced growth rates, and possibly greater activity levels earlier on sunny days. These attributes would provide a selective advantage in Northern locales.