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Garter / Ribbon snake

Black-necked Garter Snake

Harmless

Thamnophis cyrtopsis

Black-necked Garter Snake
Thamnophis cyrtopsis, © Cody Stricker
Black-necked Garter SnakeBlack-necked Garter SnakeBlack-necked Garter SnakeBlack-necked Garter SnakeBlack-necked Garter Snake

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

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

Distribution from GBIF & iNaturalist. Venom status per CDC. Background: Wikipedia. Informational only. Never handle a snake to identify it.