[GarterGuy]

Well unfortunately when it comes right down to it, it is a matter of colour and pattern. T.s.sirtalis and T.s.pallidulus are only subspecies...it's kind of like the Cal.Redsided (T.s.infernalis) and the SanFran.garter (T.s.tetrataenia)...if you really look at them, they're the same snake, except that infernalis has red bars on its sides and tetrataenia has red stripes. With sirtalis and pallidulus, it seems to be that pallidulus usually has the dorsal stripe reduced or absent and the spots on it tend to be vary numerous (even to the point of forming "crossbars" across the back) and smaller then sirtalis. Most sirtalis that have a lot of spotting seem to have fairly large spots running down the sides or even sort of checkered pattern on them, but don't have the fine spotting that you see in pallidulus. Something also to remember here is that since they're just subspecies and their territories cross over, there's probably some hybridization between to the two which will only make things more complicated for ID. I've also found here and there, some people who don't actually consider pallidulus to be a distinct subspecies and would just include it with sirtalis....so who knows, pallidulus may become invalid at some time. I know snake ID is hard, especailly at the subspecies level and particularily with as widely distributed and highly variable a species as T.sirtalis. Hope this helps out some.

Roy