Almost everyone can identify a “garter snake” in Utah!
But here’s the problem:
There are multiple species and sub-species of garter snakes! Therefore, figuring out the identity of the SPECIFIC snake you are observing can be challenging. This is especially true since many of them have similar appearances and behaviors.
Today, you are going to learn about 3 garter snake species in Utah!
- *Just a quick note – to be officially considered a garter snake, the species must be in the genus Thamnophis*
#1. Terrestrial Garter Snake
- Thamnophis elegans
- Adults range from 18 to 41 inches in length.
- Most adults have three yellow, light orange, or white stripes; one down their back and two down their sides.
- Coloration is widely variable. Individuals may be brownish or greenish. Some have red and black spots between the stripes, and occasionally all black individuals are found.
This garter snake can be difficult to identify in Utah!
Even trained herpetologists have issues! Its coloration varies widely, and there are believed to be 6 subspecies, although scientists still debate this.
Terrestrial Garter Snakes occupy various habitats, including both grasslands and forests. They can even be found in mountainous areas up to 13,000 feet above sea level. As the name suggests, they’re primarily found on land. But interestingly, these garter snakes can swim well!
This species is the only garter snake in Utah with a tendency to constrict prey! Most garter snakes grab their prey quickly and just swallow, rubbing their prey against the ground if necessary.
Terrestrial Garter Snakes aren’t aggressive or dangerous, but they do possess mildly venomous saliva! It can cause a muscle infection or even kill some muscle tissue. Most bites on humans just cause pain and some swelling.
#2. Valley Garter Snake
- Thamnophis sirtalis fitchi
- Adults range from 18 to 55 inches in length.
- Coloration is brown to black with three yellow stripes; one down the back and one down each side.
- Pronounced red bars between the yellow stripes. Yellowish chin, jaw, and belly, and a black head, which often has red sides.
- Subspecies of the Common Garter Snake.
Valley Garter Snakes are found in various habitats, including forests, wetlands, scrublands, fields, shorelines, and rocky areas. They’re also well adapted to humans and are often found in urban areas.
Look for these garter snakes in northern Utah under rocks, logs, and other objects, which they use for cover and thermoregulation. During the winter, they hibernate, often communally below the frost line. They will use a variety of underground cavities, including mammal and crayfish burrows, rock crevices, ant mounds, as well as manmade spaces such as foundations and cisterns.
When disturbed, Valley Garter Snakes will try to escape into the water and are excellent swimmers. If captured, be prepared for them to release musk and feces onto your hands! They may also strike, but only if they feel extremely threatened.
The Valley Garter Snake is considered a species of low risk. They are quite common and adapt well to human-modified habitats. However, they are frequently killed on roadways and are sometimes killed out of fear.
#3. Black-necked Garter Snake
- Western Black-necked Garter Snakes are dark olive with an orange-yellow stripe down the back and a yellow to white stripe down each side. It can be up to 42 inches long.
- Eastern Black-necked Garter Snakes are smaller and only grow up to 20 inches in length. They have a checkered pattern of black and yellow on their body, in between their three stripes.
- Both subspecies have a gray head that contrasts strongly with the body. In addition, there is a dark blotch on each side of the neck.
This species is found in many habitats, including desert scrub, plains, arid grasslands, and pine-oak woodlands. They’re almost always found in Utah in association with water sources such as streams, ciénegas, and cattle tanks.
There are two sub-species of this garter snake; the Western AND Eastern. They look different (see photo above), but they also behave uniquely. The Western subspecies (Thamnophis cyrtopsis cyrtopsis) are water snakes and most often found in the actual water. The Eastern (Thamnophis cyrtopsis ocellatus) subspecies prefer to live on DRY LAND that is very close to water.
The Black-necked Garter Snake’s preferred prey is frogs, toads, and their tadpoles, including poisonous species like the Sonoran Desert Toad. However, they have been known to feed on a wide range of other prey, including earthworms, skinks, salamanders, crustaceans, and birds.
Black-necked Garter Snakes adapt well to introduced species like the American Bullfrog. They have also benefited from the creation of cattle tanks since these snakes are dependent upon water.
Do you need additional help identifying garter snakes?
Try this field guide!
Which of these garter snakes have you seen in Utah?
Leave a comment below!