Not the only onessssss

 

 

When we were at the Gualala River recently, we realized we were not the only ones searching for toads.  We came across a few garter snakes, including the one above that had swallowed a toad!  (More on this below...)

 

There are several species of garter snakes in this area, which can make them challenging to identify.

 

Two of the snakes we saw had a lot of red coloration on their heads and bodies.  Here's a side view of the same snake shown in the first photo:

 

I could use some help, but my guess on this individual is California Red-sided Gartner Snake (Thamnophis sirtalis infernalis).  

We also photographed a different individual that I think might be the same species:

 

 

 

 

But the third snake looked very different:

 

 

 

Here's a side view of the same individual:

 

 

 

The identification of this snake was confusing to me.  Usually garter snakes have a paler yellow dorsal stripe down the middle of the back.  This one only had a partial stripe on the neck.  

As you can see, there is no red coloration anywhere.  And if you're interested in comparing, the labial scales (along the jaw, below the eye) and the internasal scales (between the nostrils) are different (in number and shape, respectively) relative to the first two snakes.

My best guess right now for the third snake is an Aquatic Garter Snake (Thamnophis atratus, possibly Thamnophis atratus hydrophilus).  But I haven't been able to locate another example of an Aquatic Garter Snake with this coloration.  [The color pattern is a better match for a Two-striped Garter Snake (Thamnophis hammondii), but that species isn't found in Sonoma County.] 

 

If you have any input about these identifications, I'd be grateful for any feedback!

P.S.  Fun natural history note: If you look closely at the first photo in this post, you'll see that the snake looks swollen in its midsection.  We weren't sure what was causing that at first, but while Eric was watching the snake, it regurgitated a partially digested toad!