Came across an easter gartersnake around 11am which had just nabbed a green frog by the foot. What follows is my documentation of a 3 hour struggle.

At first, the gartersnake had a hold of a single leg. But it wanted more. It was quite a battle to get the second leg. After many attempts and quite a few kicks free (not of both legs), the garter grappled the other leg into its control.

Which was the first moment where it showed off its unhinged jaw.

Time lapse of the next few minutes

After so much back and forth it was surprising to see how quickly the snake gained the upperhand. The frog hadn’t given up yet. Notice in the next two photos how the frog was blowing itself up to appear too big to eat.

Though not big enough apparently.

Notice how the snake is bunching up a little. It seemed like that was one method it used to gain ground on the frog. It was slinking up the frog to get more into its stomach. This occassionally backfired and resulted in lost ground.

Cool moment to stop and appreciate the stretched out gartersnake. You can clearly see the keeled scales and the blue checker pattern on its side.

First issue was getting a hold of the frog, then both legs, slight slowing of progress to deal with the puffed up stomach, and now the next challenge is the front legs.

Quick pause to point out another frog no more than a foot in front of this action, hanging out in the stream. Lots of food around.

Second method of the garter to gain ground, inching its jaw forward. Also note the frogs clear eyelid closed.

Surprised this garter could choke the whole thing down. Got the head in and pushed the front legs up to get them in last.

Required a couple moments to open its mouth and push the frog a little bit further down and into its stomach. Then off with a happy little frog bolus in its belly.

Natural History Observations and Comments

It was a day to remember. All natural history observations are. It is mind boggling to think about how much nature occurs unrecorded or even witnessed by humans. Today I was reminded what it must feel like to be a part of the food chain. The Green Frog was snuck up on by a predator and was within a couple inches of escape. Unfortunately that was all it took. At the instance of the first bite the frog was not ready to submit. It jumped, kicked, and bloated itself to make itself as difficult of a meal as it possible could. Despite the added effort,the Eastern Gartersnake hung on and waited. Even though this process required the snake to be out in the open and vulnerable for longer. Both organisms were exposed to potential threats from humans, birds, or other predators. If not the outcome that was witnessed, the frog would have been injured; decreasing its ability to find food, evade future predators, and exposing itself to risks of infection. The snake would have expended its energy supply with no reward. Making its next attempt at dinner all the more dire.

In terms of biological observations, we witness why populations decrease as you rise up the food chain. A larger amount of food is required for sustenance and even though my stream has 10s to 100 frogs there are only a handful of gartersnakes that roam the property. Part of the struggle we saw occurred because of the lack of intensity of gartersnake venom. The debate is out on whether or not the Duvernoy’s gland is a primative venom gland or not. It is known that the secretions and saliva produced from the gland, when subcutaneously injected can cause pain and swelling and is therefore toxic. The question is truly whether it serves that function or if it serves as a mere digestive fluid. Anatomically it was fascinating to see how the garter unhinged it’s jaw and slowly inched itself further forward on the frog’s back side. Meanwhile constricting its body and inching the frog further into it’s digestive tract. What we are truly seeing is not an unhinged jaw (that is us projecting our human anatomy onto them), but instead their extra bone that connects their jaw and skull while ligaments on the sides allow their jaws to stretch extra wide. Additionally, this jaw inching motion is a result of the absence of a connection between their right and left sides. Once inside their mouth, contractions of the esophagous and some internal reorranging allow the prey to fit into their body length stomach. This was witnessed as the ends of the frog were disappearing and the snake was opening its mouth as the contractions occurred. With no more frog visible on the outside, the snake is off to find a warm spot and let their digestive acid begin its work. It is now satiated for the next couple weeks before it must begin its search for another frog.