Garter / Ribbon snake
Black-necked Garter Snake
HarmlessThamnophis cyrtopsis






6 photographs of the Black-necked Garter Snake. © Cody Stricker.
The Black-necked Garter Snake (Thamnophis cyrtopsis) is a non-venomous snake in the Colubridae family, recorded in 5 countries.
- Also called
- Garter / Ribbon snake
- Family
- Colubridae
- Size
- Slender, 1.5–3 ft.
- Habitat
- Almost anywhere with moisture — gardens, fields, wetlands, and streamsides.
- Behavior
- Harmless and active by day; may release musk if handled. The most commonly seen snakes across most of the U.S.
- Identify
- Slender body with three light stripes running the length of a darker back.
About the Black-necked Garter Snake
Common names: blackneck garter snake, black-neck garter snake
Thamnophis cyrtopsis, the blackneck garter snake, is a species of garter snake of the genus Thamnophis. It is native to the southwestern United States, Mexico and Guatemala, and can be found in a wide range of different habitats, often near water sources.
Description
There are three recognized subspecies of the blackneck garter snake, two of which, Thamnophis cyrtopsis cyrtopsis and Thamnophis cyrtopsis ocellatus, are described below.
Western blackneck garter snake
Thamnophis cyrtopsis cyrtopsis (Kennicott, 1860)
The western blackneck garter snake may attain 107 cm (42 inches) in total length. The snake is colored dark olive with an orange-yellow stripe that is displayed on the middle of the body from the top while the underside is usually a cream or light shade of gray. The western blackneck is a water snake that lives near rivers, swims, and eats small fish and tadpoles.
Eastern blackneck garter snake
Thamnophis cyrtopsis ocellatus (Cope, 1880)
The eastern blackneck garter snake is smaller than the western blackneck garter snake, with an average total length of less than 51 cm (20 inches). It is frequently found on dry land near a water source rather than in water. It displays three light stripes on a dark-colored body with uniform orange and orange-yellow spreading throughout.
Geographic range
The blackneck garter snake can be found in southeastern and central Arizona, parts of the southwestern United States, Mexico and Guatemala.
Habitat
Found near water in desertscrub, grasslands, chaparral, woodland environments.
Behavior
It is active during the day and during twilight activities, and occasionally at night, hibernating from late fall to winter and mating in late spring or summer.
Feeding
Hunts in rivers for small fish, amphibians, other snakes, and invertebrates, such as earthworms.
Adapted from Wikipedia, available under CC BY-SA.
Frequently asked: Black-necked Garter Snake
- Is the Black-necked Garter Snake venomous?
- No. The Black-necked Garter Snake (Thamnophis cyrtopsis) is non-venomous and is not considered dangerous to humans. Like most snakes, it will retreat rather than bite when given the chance.
- Is the Black-necked Garter Snake poisonous?
- Snakes are venomous, not poisonous. "Poisonous" means harmful to eat or touch; "venomous" means injecting toxins through a bite. The Black-necked Garter Snake is neither poisonous nor venomous.
- Is the Black-necked Garter Snake dangerous?
- The Black-necked Garter Snake is not dangerous to humans. It has no medically significant venom and bites only defensively if cornered or handled.
- Where does the Black-necked Garter Snake live?
- The Black-necked Garter Snake has verified records in 5 countries, including United States of America, Mexico, Guatemala. See the distribution section below for its full range.
- How do I identify the Black-necked Garter Snake?
- Slender body with three light stripes running the length of a darker back.
- How big does the Black-necked Garter Snake get?
- Slender, 1.5–3 ft.
- What does the Black-necked Garter Snake eat?
- Hunts in rivers for small fish, amphibians, other snakes, and invertebrates, such as earthworms.
Where it is found
More Colubridae snakes
Common Garter SnakeThamnophis sirtalis
Western Terrestrial Garter SnakeThamnophis elegans
Western Ribbon SnakeThamnophis proximus
Northwestern Garter SnakeThamnophis ordinoides
Common Ribbon SnakeThamnophis saurita
Plains Garter SnakeThamnophis radix
Checkered Garter SnakeThamnophis marcianus
Aquatic Garter SnakeThamnophis atratus
Classification
How scientists group this snake, from the broadest category down to the exact species. Each step narrows to its closest relatives.
- OrderThe broad group of scaled reptiles: all snakes and lizards
- Squamata
- FamilyA group of related snakes that share key traits
- Colubridae
- GenusA close-knit group of very similar species
- Thamnophis
- SpeciesThis exact snake, named in the two-part scientific name
- Thamnophis cyrtopsis
Keep learning
- What to Do If You Find a SnakeFound a snake at home or on a trail? Here is how to stay calm, give it space, identify it safely, and know when to call a professional.
- Venomous vs Nonvenomous: How to Tell the DifferenceThe folk rules for telling venomous snakes apart, where each one fails, and why location-based identification beats guessing by sight.
- What Is a Snake? Anatomy and the BasicsA clear overview of what makes a snake a snake: limbless body plan, anatomy, evolution from lizards, species diversity, and why they are ectothermic.
- How to Keep Snakes Out of Your Yard and HomeA practical guide to keeping snakes out of your yard and home using habitat changes that work, plus what to skip and what to do if one shows up.
Distribution from GBIF & iNaturalist. Venom status per CDC. Background: Wikipedia. Informational only. Never handle a snake to identify it.