Is there a difference in head size or shape in Nerodia fasciata between males and females? I have a pair that where identical a couple years aago when they were 14 inches or so. Now they are closer to 2 feet, a couple of dead babies showed up in their enclosure this fall. I noticed one has a much "finer" head structure than the other.

Also, their ventral patterns are nearly identical but one has red "squiggles", the other black. Is there any evidence for or against dimorphism in color?

Thanks.