Thamnophis Sirtalis Sirtalis????

[suzoo]

Hi All. I have a question. I live in Southern Missouri, and my Garter's parents were wild caught here. I am not very familiar with all the different sub-species, and thought I had Eastern Gartersnakes, (Thamnophis Sirtalis Sirtalis). However, I saw a Plains (Thamnophis Radix Radix) that looked like my 2 year old,"Gloria". So my question is, will you please look at my photos and tell me what species you think I have? I have really come to value all of your opinions!! Thanks SO much,
Suzoo

[GarterGuy]

Looks like T.r.radix to me. No T.s.sirtalis has the dark spots below the side stripe like your snakes have. That's a very good sign that you've got Plains garters Thamnophis radix radix. Also it looks like the side stripe is up higher on the body.....T.radix has the side stripe on the 3-4th scale, while T.sirtalis has it at the 2-3rd scale. Something else you can check are the number of scales......T.radix has 21 while T.sirtalis has 19. For my money, from the pics you've got up.......I'd say T.radix and considering the area they came from I'd say T.r.radix and not T.r.haydeni (which some people don't even consider a real subspecies anyways).

[abcat1993]

I thought butler's garters had them on the 3-4th scales? I'm assuming that they both have them on the 3-4th scales.

[Stefan-A]

I thought butler's garters had them on the 3-4th scales? I'm assuming that they both have them on the 3-4th scales.

Butler's has, quote, "lateral stripe involving rows 2, 3, and the lower edge of 4 (at least anteriorly)"

I think only radix and the ribbon snakes have a row 3 and 4 stripe, but of course I could be wrong.

[suzoo]

Looks like T.r.radix to me. No T.s.sirtalis has the dark spots below the side stripe like your snakes have. That's a very good sign that you've got Plains garters Thamnophis radix radix. Also it looks like the side stripe is up higher on the body.....T.radix has the side stripe on the 3-4th scale, while T.sirtalis has it at the 2-3rd scale. Something else you can check are the number of scales......T.radix has 21 while T.sirtalis has 19. For my money, from the pics you've got up.......I'd say T.radix and considering the area they came from I'd say T.r.radix and not T.r.haydeni (which some people don't even consider a real subspecies anyways).

Thank you all! But when you say check the number of scales, where am I counting? Circumference? Length? I'm a noobie. I've worked for Vet's and caught and raised snakes for years but not professionally. Or to the extent that I'm wanting to now!

[Stefan-A]

Thank you all! But when you say check the number of scales, where am I counting? Circumference? Length? I'm a noobie. I've worked for Vet's and caught and raised snakes for years but not professionally. Or to the extent that I'm wanting to now!

Start at the big ventral scales and call them scale row 0. Then move up the side at a 45 degree angle. Count anywhere that isn't too close to the head or behind the cloaca.



Edit: I should be a bit more observant, he meant counting the dorsal scale rows (circumference).

[GarterGuy]

Hey, cool pic for scale counting! Yeh, you count up like this and when you get to the dorsum of the snake, it'll be the same down the other side. So if you count up 11...that means that's 10 scales on either side, with one on top.....total of 21, which it should be for you T.radix.

[suzoo]

Thank you! Thank you!! I will now go count the scales of my snakes! Better than counting sheep, as that has never worked for me, and it's way past my bedtime. lol

[suzoo]

Well, Thank you all VERY much!!! Gloria was a little cranky as she's fixing to shed, but Gerdie(the one as my Avatar) held perfectly still, and the count is 21. You were all right as I knew you would be My snakes are T.Radix!
Again, thanks, Suzoo

[Cazador]

Two more cents to spend as you choose... Rossman et al. recommend counting the dorsal scales beginning with the 10th one in front of (anterior to) the vent since the number of dorsal scales can vary within a single subspecies and even on the same individual, between the vent and the neck.