Garter Snakes are often associated with mesic (wet) environments, from river edges to ponds and lakes. In some areas, they are in fact only found in this type of habitat. As you’d imagine, they can swim extremely well, but do have slightly different habits to fully aquatic snakes such as Water Snakes.
In this article, I’ll be telling you about how well Garter Snakes can swim, but also how their biology is linked to water. In my experience, the two are almost always linked.
Garter Snakes and water
In many areas, water courses are biodiversity hotspots. This means they attract a variety of different species, and often a greater abundance of invertebrates and amphibians, which is great for little predators like Garter Snakes.
They also tend to be the last type of habitat to be completely destroyed by human activity. In many areas, the local river with its mostly unkempt banks is the one area where a variety of wildlife is still abundant.
This is pretty convenient for Garter Snakes, who belong to the Natricinae subfamily, are group of colubrid snakes that are mainly aquatic and semi-aquatic. They have an evolutionary history that means the like amphibian and arthropod prey, and instinctively try to stay close to water.
All-in-all, this means two things:
- Garter Snakes have evolved to stay close to water, because of the abundant small prey that they like
- Garter Snakes are often most abundant around (and sometimes confined to) watery habitats like rivers, streams and ditches because they are the last habitats to remain in human populated areas
Garter Snake swimming ability
All snakes can swim, and like their relatives, Garter Snakes move through the water by way of undulation. They make themselves a lateral “s” shape that starts about a third of the way down their body then moves all the way down to the tail.
This pushes each part of their body in turn against the water and pushes them forwards. In this respect, they swim like most terrestrial or semi-aquatic species.
Interestingly, most scientists think that snakes first evolved for a fossorial, or burrowing lifestyle. Funnily enough, the wriggling movements used for burrowing through loose substrate are very similar to those used for swimming.
It would seem snakes are perfectly adapted to move through any medium – solid or liquid – why is probably why we see so many lizards and even amphibians that have evolved to lose their legs and adopt an ophidian body plan.
How Garter Snakes compete with other snakes
As you’d expect, Garters aren’t the only snakes that live around water. They just happen to be one of the more well-known groups of species in the US that does so.
In fact, there are several sympatric species (living within the same distribution) that also thrive in wetlands and other mesic environments. The reason they are able to live together without directly competing is that each species has a favorite food source, and favorite way of escaping predators.
Crayfish Snakes, for example, eat only crayfish – they don’t compete with Garter Snakes for food. Ribbon Snakes eat similar food, but they at the water’s edge more of the time, and use water as their escape route.
Garter Snakes will simply venture further away from the banks or into surrounding woodland if they find themselves competing with too many Ribbon Snakes for prey.
When two species share an environment but use it differently, this is called niche partitioning, whereas when they share an environment hunt different prey it’s called resource partitioning.
Check out the table below detailing my observations of how Garter Snakes and their competing sympatric species swim to learn how they use niche partitioning to avoid direct competition:
| Snake species | Swimming habits |
| Garter Snakes (Thamnophis spp.) | – swim close to edge, unless logs or lily pads are present to rest on – mostly stay on top of water |
| Ribbon Snakes (Thamnophis spp.) | – extemely fast – swim on top of water but will go all the way out into open water to escape predators |
| Queen Snake (Regina septemvittata) and Graham’s Crayfish Snake (Regina grahamii) | – swim slowly on the bottom of clear streams to look for freshly-shed crayfish |
| Water Snakes (Nerodia spp.) | – swim in all parts of the water column – quickly dive underwater to escape predators |
How long can Garter Snakes swim?
Garter Snakes are excellent swimmers, and realistically they could probably swim all day. The reason for this is pretty simple: they can pause and float at any give time.
Like all colubrid species, Garter Snake have only one lung. Their right lung is bigger to make up for the absence of a left lung, and it runs about a third of the snake’s length.
This mean they have a built-in floatation device, which is highly effective given that they generally aren’t very big. All a Garter Snake needs to do if it wants to have a rest while swimming is take a couple of deep breaths.
What’s likely, however, is that you won’t see a Garter Snake swimming for long in open water. In fact, whenever you see them foraging in water, it’s usually at the water’s edge, or going from one piece of floating vegetation to another.
The reason for this is that open water is dangerous for snakes that swim on the surface like Garters. Being there for too long will make them targets for birds, bass, pike, and even Snapping Turtles.
Adaptations of Garter Snakes for Swimming
In truth Garter Snakes don’t have a lot of adaptations that directly help them swim. The main one is their slender, agile body.
This body type is good for swimming quickly across the surface of the water. In fact, you’ll notice is that their relatives the Ribbon Snakes are more slender, and even faster when they swim.
Another adaptation that they have is keeled scales. This type of scale has a ridge down the middle, making the whole snake feel rough.
The problem is that no one can quite decide whether these scales help snakes swim or not. The majority of aquatic snakes in North America, but so do the exclusively terrestrial Rattlesnakes.
At this time the jury is still out on this one!
Can Garter Snakes swim? Conclusion…
Garter Snakes are excellent swimmers, who utilise wet habitats to easily find prey. On occasion, they also take to the water to escape predators.
Swimming and foraging around the edges of bodies of water is an important part of their ecology, which is why you often find most of them near water.
Though they all like water, most Garter Snakes are not fully aquatic. They avoid directly competing with aquatic and semi-aquatic snake species by spending a little more time on land, and hunting for slightly different prey.
FAQ related to whether Garter Snakes can swim
Do garter snakes like to be in water?
Garter Snakes love to be in water. They aren’t as comfortable diving in deep water as Water Snakes, but they do forage in shallow water. If you have a pet Garter Snake, you can give it a large bowl to swim in, and put guppies or minnows in for it to catch. Do not give it only fish for food, however, as this can cause vitamin B (thiamine) deficiency.
Can garter snakes swim under water?
Garter Snakes can indeed swim underwater, and will occasionally hunt below the surface. Overall, they don’t do it as much as fully aquatic species though. They also hunt prey on land, and may even stray from water sources to forage for terrestrial prey like toads.
Can a garter snake hurt you?
Generally speaking, a Garter Snake can’t hurt you. It is safe to pick up a Garter Snake, as bad reactions to their bites are extremely rare. That said, it’s worth mentioning that Garter Snakes will void the contents of their cloaca on you if you pick them up. This contains foul-smelling musk from their scent glands, and it can be hard to get rid of the smell.
What is the difference between a garden snake and a garter snake?
There is no difference between a garden snake and a garter snake. It’s just two different common names for the same group of species. Garter Snakes often wander in gardens in search of bugs and amphibians to eat. Over time, the people in some areas starting calling them Garden Snakes because of this habit.
