Sympatry or Intergradation Between L.t. syspila and L.t. elapsoides in Western Kentucky

Lampropeltis triangulum syspila (the Redmilk Snake) and Lampropeltis triangulum elapsoides (the Scarlet Kingsnake) are small to medium tricolored snakes belonging to a much larger group that ranges throughout most of the US, Mexico, Central American and much of South America. Although currently listed as members of the same species, there is a growing belief that they may in fact represent two distinct species. In western Kentucky where both occur, they have been described by some as intergrading, and by others as living in sympatry. To test these alternative hypotheses, we have analyzed mitochondrial 16s rRNA gene sequence from both subspecies to look for the presence or absence of gene flow. A comparison of the roughly 860 base pair sequence of 16s gene sequence from both subspecies shows nearly a seven- percent difference. Sequence from L.t. syspila from areas where both occur shows sequence identity to reference L.t. syspila from areas where only it occurs. Similarly, sequence from L.t. elapsoides from sympatric areas shows only identity to reference L.t. elapsoides form more southern reference populations where only it occurs. Although we are still in the process of collecting more samples, the data so far gives no indication of gene flow, and supports the second hypothesis that these two subspecies in western Kentucky are living in sympatry and acting as two true species