Not having observed specimens of quadrivittata from its entire range, I question those who have whether or not they would consider an animal with both the dorsal markings associated with juveniles of both species and the striping associated with adult yellow rat snakes to be a yellow rat snake. I am referring to mature animals, not juveniles. In other words, where do you draw the line as to whether any given example is black, yellow, or greenish? I would say that if an adult has only stripes regardless of color it is a yellow rat snake. (Coloration is generally associated with locality with the brighter yellow animals typically found in the southern extent of its range) If an adult has both the lateral striping found in yellow rat snakes and the dorsal markings found in adult gray and juvenile black snakes it makes sense to say intergrade. Aside from geographic isolation natural intergradation has undoubtedly been responsible for the creation of many new species throughout time. Extensive DNA testing could answer all of our questions as well as turn the corn snake world completely upside down! LOL Until that time this topic will always be open for debate. The fact remains that some of our pioneering herpetologists recognized the greenish rat snake as an intergrade of black x yellow. If there are any credible published articles or books that do not support this I would greatly appreciate being directed toward them.































of dark melanin in the black rat is associated with the fact that these dorsal markings persist in to adulthood. The striping is an influence of yellow rat snake. An investigation in to this would be greatly assisted and most likely be brought to conclusion with DNA sampling. Perhaps such a project will be conducted one day. I would venture to say that along with geographic isolation natural intergradation has most likely been responsible for many of our present species

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